Male and female anatomical homologies in the perineum of the dog (Canis familiaris)

Abstract Understanding the homologies between male and female perineal structure helps both evolutionary biologists and clinicians better understand the evolution and anatomy of canines. Domestic dogs (Canis familiaris) play an important role in human society, and canine perineal anatomy is important for maintaining dogs’ reproductive health for successful breeding and a wide variety of pathologies. Here, we investigate homologies between male and female perineal structure, identifying structures based on common function, anatomical relationships and attachments. In this investigation we dissected 21 male and female large‐breed dogs. We find broad structural homologies between male and female dogs related to erection, micturition and defecation, including muscles, fasciae and erectile tissue. Using these homologies will help anatomists and clinicians interpret the anatomical organization of the perineum, a notoriously difficult area of anatomy

Leptin-deficient mice have altered three-dimensional growth plate histomorphometry

Abstract Background Leptin is an adipokine that regulates energy homeostasis and is also needed for normal bone growth and maintenance. Mutation in the lep gene, which characterizes the ob/ob mouse model, results in the development of obesity and type 2 diabetes mellitus, as well as reduced limb bone length and increased fracture risk. However, the relationship between limb bone length and growth plate cartilage structure in obese diabetic adolescents is incompletely understood. Here, we tested the hypothesis that leptin deficiency affects the microstructure of growth plate cartilage in juvenile ob/ob mice. Methods Tibial growth plate cartilage structure was compared between lean and obese, leptin-deficient (ob/ob) female mice aged 10 weeks. We used confocal laser scanning microscopy to assess 3D histological differences in Z stacks of growth plate cartilage at 0.2 µm intervals, 80–100 µm in depth. Histomorphometric comparisons were made between juvenile lean and ob/ob mice. Results We found obese mice have significantly reduced tibial length and growth plate height in comparison with lean mice (P < 0.05). Obese mice also have fewer chondrocyte columns in growth plate cartilage with reduced chondrocyte cell volumes relative to lean mice (P < 0.05). Conclusions These data help explicate the relationship between growth plate cartilage structure and bone health in obese diabetic juvenile mice. Our findings suggest obesity and diabetes may adversely affect growth plate cartilage structure

Genistein Suppresses IL-6 and MMP-13 to Attenuate Osteoarthritis in Obese Diabetic Mice

Type 2 diabetes mellitus and osteoarthritis (OA) often present as comorbidities. We examined the role of plasma IL-6, chondrocyte MMP-13, and col10a expression in the development of OA in obese diabetic mice. We further investigated dietary genistein and exercise training as potential mitigators of OA. One hundred adult mice (50 females, 50 males) aged 6 weeks were randomized into 5 groups, including lean controls, obese diabetic controls, and obese diabetic mice treated with genistein, exercise training, and genistein plus exercise training. The obese diabetic state was induced by feeding the mice a high-fat, high-sugar diet. Genistein was incorporated into the diet at a concentration of 600 mg genistein/kg. Exercise training was performed on a treadmill and consisted of daily 30 min sessions at 12 m/min, 5 days/week for a 12-week period. After treatment, plasma was collected, and proximal tibias were removed for analysis. Plasma IL-6 and MMP-13 were elevated while col10a was reduced in obese diabetic mice in comparison to lean controls. Dietary genistein treatment reduced IL-6 and MMP-13 expression and increased col10a expression. Histological examination of articular cartilage showed reduced thickness of the uncalcified zones and proteoglycan content in the cartilage of diabetic mice in comparison to mice fed genistein. Exercise training had no significant effect. In conclusion, genistein (and not exercise training) attenuates OA by reducing IL-6 and MMP-13 expression in diabetic mice

Histological study of white rhinoceros integument

<div><p>In this study, we report findings from a microscopic analysis of the white rhinoceros (<i>Ceratotherium simum</i>) integumentary ultrastructure. Skin samples from the cheek, shoulder, flank and rump were taken from a 46-year-old female southern white rhinoceros and examined using H&E and elastic histological stains. The epidermis was thickest in the flank (1.003 mm) followed by the rump, cheek and shoulder. The stratum corneum comprised more than half the epidermal thickness. Numerous melanin granules were found in the basal and spinosum layers. The epidermal-dermal junction was characterized by abundant papillary folds increasing surface contact between integument layers. Most of the dermal thickness consisted of organized collagen bundles with scattered elastic fibers. Collagen fiber bundles were thickest in the flank (210.9 μm) followed by shoulder, rump and cheek. Simple coiled sweat glands were present in the dermis, but hair and sebaceous glands were absent. Together, these data suggest the white rhinoceros has a unique integumentary system among large terrestrial herbivores.</p></div

Apocrine gland in the dermis of the white rhinoceros.

<p>This type of gland was found in all of the body regions sampled. Verhoeff-Von Gieson elastic stain. Scale bar is 100 μm on left, 50 μm on right.</p

Comparison of epidermal layers of white rhinoceros integument.

<p>Sections are from the (A) cheek, (B) shoulder, (C) flank, and (D) rump. Arrows point to dermal papillae, extension of the papillary layer of the dermis into the epidermis [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0176327#pone.0176327.ref007" target="_blank">7</a>]. Verhoeff-Von Gieson elastic stain. Scale bar is 100 μm.</p

Malpighian layer of the epidermis and papillary layer of the dermis.

<p>Strata basale and spinosum of the epidermis (i.e., Malpighian layer) at higher magnification exhibit regions with high concentrations of melanin granules, also known as mature melanosomes (brown intracellular material in the region of the asterisk) [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0176327#pone.0176327.ref007" target="_blank">7</a>]. Clear cells in the epidermis are also visible that have morphology consistent with that of Langerhans’ cells (arrowheads) [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0176327#pone.0176327.ref009" target="_blank">9</a>]. The papillary layer of the dermis demonstrates dark-staining elastic fibers (arrows). The inset shows a blowup of the stratum spinosum with regions of densely packed keratinocyte desmosomal intercellular junctions (narrow arrows indicating numerous parallel, dark-staining lines between cells). Verhoeff-Von Gieson elastic stain. Scale bar is 50 μm.</p

Thickness of epidermal layers and dermal collagen bundles (μm; mean ± SD).

<p>Thickness of epidermal layers and dermal collagen bundles (μm; mean ± SD).</p