Ultrastructural studies of fibroadenomatous hyperplasia of mammary glands of 2 cats

Feline breeding and pregnancy management: What is normal and when to intervene

Practical relevance:

Cats are common pets worldwide. Successful breeding of cats starts with the selection of suitable breeding animals, and care should be taken to avoid inbreeding. Keeping cats in smaller groups reduces stress and facilitates management.

Clinical challenges:

Breeding cats is challenging in many ways. Group housing is a common scenario, and care should be taken not to have groups that are too large, because of the risk of stress and infectious diseases. Feline pregnancy and parturition both vary in length, which is one reason why it may be challenging to diagnose dystocia. In queens with pyometra, a vaginal discharge may not be evident due to their meticulous cleaning habits.

Audience:

This review is aimed at clinicians in small animal practice, especially those in contact with cat breeders.

Patient group:

Reproductive emergencies occur in both intentionally and unintentionally bred cats, and more often in young or middle-aged queens. Pyometra tends to be a disease of older queens.

Evidence base:

Evidence is poor for many conditions in the breeding queen, and information is extrapolated from the dog or based on case reports and case series.

Artesunate attenuates proliferation of epithelial cells by downregulating the NF-κB and AKT signaling pathways in benign mammary gland hyperplasia rats

Background

The aim of this study was to investigate the effects of artesunate (ART) on breast epithelial cell proliferation in vitro and in vivo.

Methods

Immortalized human non-cancer mammary epithelial (MCF-10A) cells were used to determine the effect of ART on estrogen-induced mammary hyperplasia cells. We investigated the effect of ART on the synthesis of cyclooxygenase-2 (COX-2) and proliferating cell nuclear antigen (PCNA) in MCF-10A by treating MCF-10A 36 h with different concentrations of ART (0, 100, 200, 400 µm, n=12/group). We then investigated the effect of ART on estrogen induced COX-2, PCNA, nuclear factor-kappa B (NF-κB), and pNF-κB synthesis by treating MCF-10A with both estrogen and ART (0, 50, 100, 200 µm, n=12/group). A mammary hyperplasia model (MGH) was established in rats. All rats (n=12) were divided into 4 groups [group A: negative control (NC) + Art −; group B: NC + Art +; group C: MGH + Art −; group D: MGH + Art +] by the random number table method and the effects of ART on estradiol-induced mammary hyperplasia, fibrosis, and phosphorylation of AKT and NF-κB were studied by histopathological staining, Masson trichrome staining, immunohistochemistry (IHC), and western blotting.

Results

The proliferation and inflammation of mammary epithelial cells were blocked by ART (P<0.05). The phosphorylation of NF-κB induced by estradiol in MCF-10A was attenuated by ART (P<0.05). In the rat MGH, ART reduced cell proliferation and fibrosis (P<0.05) and inhibited the phosphorylation of AKT and NF-κB (P<0.05).

Conclusions

The drug ART inhibits estrogen-induced breast hyperplasia by blocking AKT and NFkB phosphorylation.

Ultrastructure of feline mammary hypertrophy

The ultrastructure of feline mammary hypertrophy was studied in a five-month-old female which had aborted recently, a ten-year-old female which was one month postestrus, and a four-year-old progestin-treated neutered male. Morphologic comparisons were made to normal mammary tissue from a one-year-old female cat. Hypertrophied mammary tissue had the same cell types and spatial relationships as did the normal gland. Major differences included a more highly developed duct system composed of metabolically active cells which often were arranged in multiple cell layers, and periductular stroma with increased fibroblasts and vascularization. Hypertrophied epithelial cells were characterized generally by smooth-contoured nuclear membranes, more evenly dispersed heterochromatin, prominent nucleoli, increased polyribosomes, and elongated mitochondria. Secretory activity was developed significantly only in the cat that had aborted recently. Modifications in myoepithelial cells included: more evenly dispersed nuclear heterochromatin, thicker bundles of cytoplasmic filaments, more straight plasma membranes along the basal lamina, and elongated hemidesmosomes. Multilayering of the basal lamina was accentuated. Stromal fibroblasts had nuclear heterochromatin distributed similarly to that of epithelial and myoepithelial cells, and increased rough endoplasmic reticulum. Myoepithelial cells did not contribute to the increased stromal cellularity. No significant ultrastructural differences were noted between mammary hypertrophy in young, old, and progestin-treated cats.