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Scleral stiffening may protect against glaucomatous retinal ganglion cell (RGC) loss or dysfunction associated with ocular hypertension. Here, we assess the potential neuroprotective effects of two treatments designed to stiffen either the entire posterior sclera or only the sclera adjacent to the peripapillary sclera in an experimental model of glaucoma.Rat sclerae were stiffened in vivo using either genipin (crosslinking the entire posterior sclera) or a regionally selective photosensitizer, methylene blue (stiffening only the juxtaperipapillary region surrounding the optic nerve). Ocular hypertension was induced using magnetic microbeads delivered to the anterior chamber. Morphological and functional outcomes, including optic nerve axon count and appearance, retinal thickness measured by optical coherence tomography, optomotor response, and electroretinography traces, were assessed.Both local (juxtaperipapillary) and global (whole posterior) scleral stiffening treatments were successful at increasing scleral stiffness, but neither provided demonstrable neuroprotection in hypertensive eyes as assessed by RGC axon counts and appearance, optomotor response, or electroretinography. There was a weak indication that scleral crosslinking protected against retinal thinning as assessed by optical coherence tomography.Scleral stiffening was not demonstrated to be neuroprotective in ocular hypertensive rats. We hypothesize that the absence of benefit may in part be due to RGC loss associated with the scleral stiffening agents themselves (mild in the case of genipin, and moderate in the case of methylene blue), negating any potential benefit of scleral stiffening.The development of scleral stiffening as a neuroprotective treatment will require the identification of better tolerated stiffening protocols and further preclinical testing.

Most animal models of glaucoma rely on induction of ocular hypertension (OHT), yet such models can suffer from high IOPs leading to undesirable retinal ischemia. Thus, animals with IOPs exceeding a threshold (e.g. > 60 mmHg) are often excluded from studies. However, due to the intermittent nature of IOP measurements, this approach may fail to detect ischemia. Conversely, it may also inappropriately eliminate animals with IOP spikes that do not induce ischemic damage. It is known that acute ischemia selectively impairs inner retinal function, which results in a reduced b-wave amplitude. Here, we explore the potential of using electroretinography (ERG) to detect ischemic damage in OHT eyes. 74 Brown Norway rats received a unilateral injection of magnetic microbeads to induce OHT, while contralateral eyes served as controls. IOP was measured every 2–3 days for 14 days after microbead injection. Retinal function was evaluated using dark-adapted bright flash ERG (2.1 log cd•s/m2) prior to, and at 7 and 14 days after, injection. We investigated two criteria for excluding animals: (IOP Criterion) a single IOP measurement > 60 mmHg; or (ERG Criterion) a b-wave amplitude below the 99.5% confidence interval for naive eyes. 49 of 74 rats passed both criteria, 7 of 74 failed both, and 18 passed one criterion but not the other. We suggest that ERG testing can detect unwelcome ischemic damage in animal models of OHT. Since brief IOP spikes do not necessarily lead to ischemic retinal damage, and because extended periods of elevated IOP can be missed, such ERG-based criteria may provide more objective and robust exclusion criteria in future glaucoma studies.

The central vision-threatening event in glaucoma is dysfunction and loss of retinal ganglion cells (RGCs), thought to be promoted by local tissue deformations. Here, we sought to reduce tissue deformation near the optic nerve head by selectively stiffening the peripapillary sclera, i.e. the scleral region immediately adjacent to the optic nerve head. Previous scleral stiffening studies to treat glaucoma or myopia have used either pan-scleral stiffening (not regionally selective) or regionally selective stiffening with limited access to the posterior globe. We present a method for selectively stiffening the peripapillary sclera using a transpupillary annular light beam to activate methylene blue administered by retrobulbar injection. Unlike prior approaches to photocrosslinking in the eye, this approach avoids the damaging effects of ultraviolet light by employing red light. This targeted photocrosslinking approach successfully stiffened the peripapillary sclera at 6 weeks post-treatment, as measured by whole globe inflation testing. Specifically, strain was reduced by 47% when comparing treated vs. untreated sclera within the same eye (n = 7, p=0.0064) and by 54% when comparing the peripapillary sclera of treated vs. untreated eyes (n = 7, p

Purpose Genipin has been proposed as a possible neuroprotective therapy in myopia and glaucoma. Here, we aim to determine the effects of prolonged genipin-induced scleral stiffening on visual function. Methods Eyes from Brown Norway rats were treated in vivo with either a single 15 mM genipin retrobulbar injection or sham retrobulbar injection and were compared to naive eyes. Intraocular pressure, optomotor response, and electroretinograms were repeatedly measured over 4 weeks following retrobulbar injections to determine visual and retinal function. At 4 weeks, we quantified retinal ganglion cell axon counts. Finally, molecular changes in gene and protein expression were analyzed via real-time polymerase chain reaction (RT-PCR) and proteomics. Results Retrobulbar injection of genipin did not affect intraocular pressure (IOP) or retinal function, nor have a sustained impact on visual function. Although genipin-treated eyes had a small decrease in retinal ganglion cell axon counts compared to contralateral sham-treated eyes (-8,558 ± 18,646; mean ± SD), this was not statistically significant (P = 0.206, n = 9). Last, we did not observe any changes in gene or protein expression due to genipin treatment. Conclusions Posterior scleral stiffening with a single retrobulbar injection of 15 mM genipin causes no sustained deficits in visual or retinal function or at the molecular level in the retina and sclera. Retinal ganglion cell axon morphology appeared normal. Translational significance These results support future in vivo studies to determine the efficacy of genipin-induced posterior scleral stiffening to help treat ocular diseases, like myopia and glaucoma.

In this work, we develop a robust, extensible tool to automatically and accurately count retinal ganglion cell axons in optic nerve (ON) tissue images from various animal models of glaucoma. We adapted deep learning to regress pixelwise axon count density estimates, which were then integrated over the image area to determine axon counts. The tool, termed AxoNet, was trained and evaluated using a dataset containing images of ON regions randomly selected from whole cross sections of both control and damaged rat ONs and manually annotated for axon count and location. This rat-trained network was then applied to a separate dataset of non-human primate (NHP) ON images. AxoNet was compared to two existing automated axon counting tools, AxonMaster and AxonJ, using both datasets. AxoNet outperformed the existing tools on both the rat and NHP ON datasets as judged by mean absolute error, R2 values when regressing automated vs. manual counts, and Bland-Altman analysis. AxoNet does not rely on hand-crafted image features for axon recognition and is robust to variations in the extent of ON tissue damage, image quality, and species of mammal. Therefore, AxoNet is not species-specific and can be extended to quantify additional ON characteristics in glaucoma and potentially other neurodegenerative diseases.

It is widely accepted that biomechanics plays an important role in glaucoma pathophysiology, but the mechanisms involved are largely unknown. Rats are a common animal model of glaucoma, and finite element models are being developed to provide much-needed insight into the biomechanical environment of the posterior rat eye. However, material properties of rat ocular tissues, including the sclera, are currently unknown. Since the sclera plays a major role in posterior ocular biomechanics, our goal was to use inverse finite element modeling to extract rat scleral material properties. We first used digital image correlation to measure scleral surface displacement during whole-globe inflation testing. We modeled the sclera as a nonlinear material with embedded collagen fibers and then fit modeled displacements to experimental data using a differential evolution algorithm. Subject-specific models were constructed in which 3 parameters described the stiffness of the ground substance and collagen fibers in the posterior eye, and 16 parameters defined the primary orientation and alignment of fibers within eight scleral sub-regions. We successfully extracted scleral material properties for eight rat eyes. Model displacements recreated general patterns of the experimental displacements but did not always match local patterns. The fiber directions and fiber concentration parameters were highly variable, but on average, fibers were aligned circumferentially and were more aligned in the peripapillary sclera than in the peripheral sclera. The material properties determined here will be used to inform future finite element models of the rat posterior eye with the goal of elucidating the role of biomechanics in glaucoma pathophysiology.

The stiffness of the sclera is important in several ocular disorders, and there is hence a need to quantify the biomechanical properties of this tissue. Here, we present two methods for measuring the stiffness of scleral ocular tissues: ocular compliance testing and digital image correlation strain mapping. In tandem with these approaches, we provide two methods to spatially quantify the anisotropic alignment of collagen fibers making up the sclera, using second harmonic generation microscopy and small-angle light scattering. Together, these approaches allow specimen-specific measurement of tissue stiffness and collagen alignment, which are key factors in determining how the eye responds to mechanical loads.

The stiffness of the sclera is important in several ocular disorders, and there is hence a need to quantify the biomechanical properties of this tissue. Here, we present two methods for measuring the stiffness of scleral ocular tissues: ocular compliance testing and digital image correlation strain mapping. In tandem with these approaches, we provide two methods to spatially quantify the anisotropic alignment of collagen fibers making up the sclera, using second harmonic generation microscopy and small-angle light scattering. Together, these approaches allow specimen-specific measurement of tissue stiffness and collagen alignment, which are key factors in determining how the eye responds to mechanical loads.

The concept of scleral stiffening therapies has emerged as a novel theoretical approach for treating the ocular disorders glaucoma and myopia. Deformation of specific regions of the posterior eye is innately involved in the pathophysiology of these diseases, and thus targeted scleral stiffening could resist these changes and slow or prevent progression of these diseases. Here, we present the first systematic screen and direct comparison of the stiffening effect of small molecule collagen cross-linking agents in the posterior globe, namely using glyceraldehyde, genipin and methylglyoxal (also called pyruvaldehyde). To establish a dose–response relationship, we used inflation testing to simulate the effects of increasing intraocular pressure in freshly harvested rat eyes stiffened with multiple concentrations of each agent. We used digital image correlation to compute the mechanical strain in the tissue as a metric of stiffness, using a novel treatment paradigm for screening relative stiffening by incubating half of each eye in cross-linker and using the opposite half as an internal control. We identified the doses necessary to increase stiffness by approximately 100%, namely 30 mM for glyceraldehyde, 1 mM for genipin and 7 mM for methylglyoxal, and we also identified the range of stiffening it was possible to achieve with such agents. Such findings will inform development of in vivo studies of scleral stiffening to treat glaucoma and myopia.

Scleral stiffening has been proposed as a therapy for glaucoma and myopia. Previous in vivo studies have evaluated the efficacy of scleral stiffening after multiple treatments with a natural collagen crosslinker, genipin. However, multiple injections limit clinical translatability. Here, we examined whether scleral stiffening was maintained after four weeks following a single genipin treatment. Eyes from brown Norway rats were treated in vivo with a single 15 mM genipin retrobulbar injection, sham retrobulbar injection, or were left naive. Eyes were enucleated either 1 day or four weeks post-injection and underwent whole globe inflation testing. We assessed first principal Lagrange strain of the posterior sclera using digital image correlation as a proxy for scleral stiffness. Four weeks post-injection, genipin treatment resulted in a 58% reduction in scleral strain as compared to controls ( p = 0.005). We conclude that a single in vivo injection of genipin effectively stiffened rat sclera for at least four weeks which motivates further functional studies and possible clinical translation of genipin-induced scleral stiffening.

Throughout the history of orthopaedics, our understanding of the function and necessity of the meniscus has significantly evolved, and with it, our techniques of treating, repairing, preserving, and replacing it have progressed in parallel. Currently, it is known that a meniscus deficiency is a predisposing factor to the development of degenerative changes of the knee. Thus, it is incumbent upon the surgeon to preserve the meniscus to the extent that biology will allow. Unfortunately, circumstances arise when the meniscus cannot be preserved, and young patients afflicted by irreparable meniscus deficiency may be potential candidates for a meniscus transplant. Though its indications are limited and its execution technically complex, meniscal allograft transplant has been shown to provide good subjective outcomes and is a potentially joint preserving surgery. This paper provides a comprehensive and historical review of the meniscus, a brief review of meniscus anatomy and biomechanics, and commentary on the role of meniscal allograft transplant for the treatment of meniscal deficiency, including patient selection, graft selection and sizing, surgical technique, and outcomes.

[ J. R. Soc. Interface 14 , 20170014 (Published online 5 April 2017) ([doi:10.1098/rsif.2017.0014][2])][2] In our recent publication entitled, ‘Quantification of the efficacy of collagen cross-linking agents to induce stiffening of rat sclera’ published on 5 April 2017 (doi:10.1098/rsif.2017.

Fondaparinux is an accepted form of deep venous thrombosis prophylaxis after hip arthroplasty. Cited advantages of its use include once-daily administration, standard dosage, and superiority as compared with enoxaparin. However, there have been several case reports of serious associated bleeding complications. We describe the case of a 77-year-old woman who developed a massive leg hematoma in the operative extremity nearly 3 weeks after a primary total hip arthroplasty while on fondaparinux. The patient developed a compartment syndrome requiring decompression of the hematoma, fasciotomy, and subsequent additional plastic surgery for split thickness skin grafting.

Extravasation injuries occur under a wide variety of circumstances in the inpatient setting. Prevention remains the ideal treatment for these iatrogenic injuries. When extravasation injuries do occur, they must be diagnosed and treated promptly to minimize the amount of soft tissue injury. Initial management is similar among vesicant extravasates. Although evidence is limited to guide management for specific extravasates, it is paramount to be aware of the described treatments and principles.

A model representing the effects of varying dietary crude protein (CP) levels on growth, survival, and reproductive success of collared peccaries is described, validated, and used to simulate population responses to selected environmental conditions. Behavior of the model on both individual and population levels is compared to available field data. At the individual level, predictions of body weight dynamics for juveniles and adults on varying CP diets compare favorably with similar data collected from captive animals. However, simulated individuals lose weight too rapidly when dietary CP remains at extremely low levels for extended periods of time. At the population level, predictions of herd size, herd structure (age-class distribution, sex ratio), seasonality of reproduction, and probability of survival exhibit trends generally similar to those observed among wild peccaries. Simulation of selected environmental conditions typical of south Texas, including a 12-month drought, and an 18-month wet period, suggests that changes in dietary CP can have a significant effect on population dynamics. Changes in juvenile survival rates are the most important factor influencing population responses to fluctuating nutritional conditions. The model relates variability in population recruitment to fluctuations in environmental conditions through the effect of diet quality on survival and reproductive performance of individuals. This approach to population modelling does not place the arbitrary density-dependent constraints on population dynamics that characterize many traditional population models. Rather, density-dependent population responses emerge as the result of ecological constraints on individuals.

Housing animals in groups that are typical of the normal social system can be very important to the success of captive husbandry. Collared peccaries normally live in mixed-sex territorial groups of 13–40 individuals with little evidence for movement between groups. We recorded 21–30 cases of infanticide in a captive group composed of animals from several wild groups. In five observed cases, the attacker was a female unrelated to the mother, but related females helped defend neonates. Victims did not differ in sex ratio or size from individuals that survived. We recommend that peccaries be housed as related female lineages.

The collared peccary (Tayassu tajacu) is a highly social ungulate possessing a large dorsal scent gland located 15-20 cm anterior to the base of the tail. The gland is ca. 10 cm long, 8 cm wide, and contains a centrally located nipple-like opening 10-15 mm in diameter. The gland emits a strong musky odor (Werner et al., 1952) and is used in social functions. The "mutual rub," when two peccaries stand head to tail and vigorously rub the side of the head over the dorsal gland of the partner (Bissonette, 1976; Schweinsburg and Sowls, 1972), constitutes ca. 12% of all behaviors and 59% of all olfaction-related behaviors (Byers, 1985). In addition, the gland functions in herd recognition and cohesion (Byers, 1985) and in scent marking (Sowls, 1984). General histology and morphology of the gland were described previously (Epling, 1956; Werner et al., 1952). Activity of sebaceous tissue located around the nipple in the peccary gland may be increased by androgens, as is found in other species (e.g., hip glands of male voles, Microtus montanus-Jannett, 1978; rump glands of Guinea pigs, Cavia porcellus-Martan, 1962), and Balakrishnan et al. (1984) found that progesterone may increase activity in sudoriferous tissue (located peripherally to the sebaceous tissue in the peccary gland). Estradiol (Ebling, 1976), estrogen (Balakrishnan et al., 1984), testosterone (Balakrishnan et al., 1984; Jannett, 1978), and adrenaline (Miiller-Schwarze, 1983) have been linked specifically to changes in scent-gland activity in various species. Age, sex, and individual differences also may affect gland function in caribou (Tarandus tarandus-Quay, 1955) and white-tailed deer (Odocoileus virginianus-Atkeson and Marchinton, 1982). In peccaries, blood concentrations of testosterone in captive subordinate males were significantly lower than those of the alpha male (Hellgren, 1984), and both blood progesterone and estradiol-17fi concentrations were significantly affected by pregnancy (Hellgren et al., 1985). Such changes in hormone concentrations may alter activity in either or both the sebaceous and sudoriferous components of the dorsal scent gland, resulting in variation in fluid composition. Tembrock (1968) suggested that changes in fluid composition may convey different information to mammalian herd members depending on physiological condition. In this study, we compare overall gland activity, differences in heights of active and inactive sudoriferous secretory cells, and relative activity levels of sebaceous tissue of juveniles

p21/WAF1/CIP1/SDI1 is an important cell-cycle mediator with tumor suppressor gene capabilities, and its inactivation could potentially lead to tumor progression. Because tumor suppressor genes are commonly inactivated by somatic and germline mutations, we analyzed a variety of human tumor cell lines for p21 mutations. We used single-strand conformational analysis and direct sequencing to identify possible mutations in the p21 coding region. Two base-alterations were observed in 41 immortalized human tumor cell lines. A previously reported polymorphism that results in a serine-to-arginine amino-acid substitution at codon 31 was found in 24% (10 of 41) of the tumor cell lines but was also found in 10% (six of 62) of normal parental DNAs tested and 7% (three of 43) of normal DNAs from patients with primary endometrial tumors. Another nucleotide substitution found at codon 80 resulted in the replacement of threonine with methionine. Codon 80 changes were found in 7% (three of 41) of the tumor cell lines (all endometrial) and in 2% (one of 62) of the normal parental DNAs. This change was not found in any of the primary endometrial tumors examined. The biological activity of these base changes was analyzed by using in vitro cyclin-dependent kinase 2-cyclin A kinase assays and calcium phosphate transfections. We observed that wild-type p21 and the p21 variants had similar growth-inhibitory abilities. Thus, our results suggest that mutation of the p21 gene is not prevalent in human tumor cell lines and is not a probable mechanism of inactivation of this gene.

Fondaparinux is an accepted form of deep venous thrombosis prophylaxis after hip arthroplasty. Cited advantages of its use include once-daily administration, standard dosage, and superiority as compared with enoxaparin. However, there have been several case reports of serious associated bleeding complications. We describe the case of a 77-year-old woman who developed a massive leg hematoma in the operative extremity nearly 3 weeks after a primary total hip arthroplasty while on fondaparinux. The patient developed a compartment syndrome requiring decompression of the hematoma, fasciotomy, and subsequent additional plastic surgery for split thickness skin grafting.

The toxicity of silica particles is inversely proportional to their size. The natural protective mechanism of the respiratory passages filters out a large percentage of the dust particles that are inhaled and very few are retained in the alveolar spaces of the lungs. The particles which are retained set up an irritation in the alveolar walls. Wandering monocytes or phagocytic cells appear from the reticulum of the cellular wall, invade the lumen of the air sac, and engulf the particles. These cells may then arrange themselves in layers upon the lining membrane of the air sac (Fig. 1), thus thickening the walls and decreasing the elasticity of the air sac, which interferes with the normal gaseous exchange. As long as the terminal bronchiole is patent, the cells gradually migrate toward the lumen and are removed with the normal bronchial drainage, which is coughed up. If a break occurs in the lining of the air sac, or in the mucous membrane of the bronchiole (Fig. 2), these dust laden monocytes invade the l...

The class of convoluted Pascal distributions obeying certain moment conditions are characterized by a system of differential equations satisfied by their probability mass functions. The result contains a characterization of Pascal distributions obtained by Boswell and Patil (1973) as a special case. (Author)