Enhanced protein-metabolite correlation analysis: To investigate the association between Staphylococcus aureus mastitis and metabolic immune pathways

Mastitis is a disease characterized by congestion, swelling, and inflammation of the mammary gland and usually caused by infection with pathogenic microorganisms. Furthermore, the development of mastitis is closely linked to the exogenous pathway of the gastrointestinal tract. However, the regulatory mechanisms governing the gut-metabolism-mammary axis remain incompletely understood. The present study revealed alterations in the gut microbiota of mastitis rats characterized by an increased abundance of the Proteobacteria phylum. Plasma analysis revealed significantly higher levels of L-isoleucine and cholic acid along with 7-ketodeoxycholic acid. Mammary tissue showed elevated levels of arachidonic acid metabolites and norlithocholic acid. Proteomic analysis showed increased levels of IFIH1, Tnfaip8l2, IRGM, and IRF5 in mastitis rats, which suggests that mastitis triggers an inflammatory response and immune stress. Follistatin (Fst) and progesterone receptor (Pgr) were significantly downregulated, raising the risk of breast cancer. Extracellular matrix (ECM) receptors and focal adhesion signaling pathways were downregulated, while blood-milk barrier integrity was disrupted. Analysis of protein-metabolic network regulation revealed that necroptosis, protein digestion and absorption, and arachidonic acid metabolism were the principal regulatory pathways involved in the development of mastitis. In short, the onset of mastitis leads to changes in the microbiota and alterations in the metabolic profiles of various biological samples, including colonic contents, plasma, and mammary tissue. Key manifestations include disturbances in bile acid metabolism, amino acid metabolism, and arachidonic acid metabolism. At the same time, the integrity of the blood-milk barrier is compromised while inflammation is promoted, thereby reducing cell adhesion in the mammary glands. These findings contribute to a more comprehensive understanding of the metabolic status of mastitis and provide new insights into its impact on the immune system.

Hesperetin regulates the intestinal flora and inhibits the TLR4/NF-κB signaling axis to protect the blood-milk barrier and prevent mastitis

The World Health Organization recommends breastfeeding for 6 months, but mastitis, a common disease during lactation, presents a major obstacle to fulfilling this recommendation. Maternal nutrient intake during lactation has been shown to be related to mastitis. Therefore, this study aimed to explore the effect of hesperetin, a phytonutrient, on mastitis. The oral administration of hesperetin to lipopolysaccharide (LPS)-induced mastitis mice alleviated their pathological damage, reduced the secretion of pro-inflammatory cytokines, and maintained the integrity of their blood-milk barrier. Moreover, our results showed that oral administration of hesperetin regulates the composition of the intestinal flora of mice. Fecal microbial transplantation (FMT) from the mice of hesperetin group alleviated LPS-induced mastitis in recipient mice. In additional, hesperetin attenuated the inflammatory response and increased the expression of tight junction proteins (TJs) in LPS-stimulated mouse mammary epithelial cells (mMECs). Through network pharmacological analysis and further research, we demonstrated hesperetin inhibits the expression of TLR4 and the activation of NF-κB signaling. In conclusion, hesperetin protects the blood-milk barrier and improve mastitis by regulating intestinal flora and inhibiting the activation of TLR4/NF-κB signaling axis. This study provides a theoretical basis for lactating females to consume hesperetin as a supplement to prevent mastitis and maintain mammary health.

Bilateral plasma cell mastitis simulating breast cancer: a case report and literature review

Plasma cell mastitis (PCM) is a chronic inflammatory disease of the breast. It is a benign entity mainly found in nonpregnant and nonlactating women. PCM presents with symptoms of inflammation, breast erythema, masses, and indurations. We herein describe a 26-year-old woman with a 2-year history of right breast swelling and a 1-year history of left breast swelling during pregnancy and lactation. She was clinically diagnosed with bilateral breast cancer, but a biopsy specimen revealed PCM. During pregnancy and lactation, PCM can present as bilateral lesions. Early presentation and diagnosis are crucial because PCM, a benign disease, can lead to remarkable morbidity if allowed to progress to an advanced stage.

Retinoic acid ameliorates low-grade endotoxemia-induced mastitis by limiting inflammatory responses in mice

Mastitis is a serious disease for humans and animals, which causes huge economic losses in the dairy industry and is hard to prevent due to the complex and unclear pathogenesis. Subacute ruminal acidosis (SARA) has contributed to the development of mastitis by inducing ruminal dysbiosis and subsequent low-grade endotoxemia (LGE), however, how ruminal metabolic changes regulate this progress is still unclear. Our previous study revealed that cows with SARA had increased ruminal retinoic acid (RA) levels, a metabolic intermediate of vitamin A that plays an essential role in mucosal immune responses. Hence, the aim of this study was to investigate the protective effect of RA on LGE-induced mastitis and the underlying mechanisms in mice. The results showed that RA alleviated LGE-induced mastitis, as evidenced by RA significantly reduced the increase in mammary proinflammatory cytokines and improved blood-milk barrier injury caused by LGE. In addition, RA increased the expression of tight junction proteins, including ZO-1, occludin and claudin-3. Furthermore, we found that RA limited the mammary inflammatory responses by inhibiting the activation of NF-κB and NLRP3 signaling pathways. These findings suggest that RA effectively alleviates LGE-induced mastitis and implies a potential strategy for the treatment and prevention of mastitis and other diseases.

Phenotypic evaluation of mast cells in bovine mammary tissue and mastitis in the context of fibrosis

This research paper addresses the hypothesis that mast cells (MCs) contribute to the formation of mammary fibrosis. MCs are important immune regulatory and immune modulatory cells that play major roles in the inflammatory process. Since there is no detailed knowledge, this research study aimed to comparatively investigate the presence, localization, and immunophenotypes of MCs in healthy and mastitic mammary tissues. A total of 264 mammary samples were evaluated for the examination of mast cells and fibrosis. The mean mast cell number in both acute and chronic mastitis samples were very significantly higher than the control group P < 0.001). A 7.9-fold increase in the number of mast cells was found when the chronic mastitis group was compared with the control (healthy) group. Immunohistochemistry revealed presence of all three immune phenotypes in control and mastitic mammary samples (tryptase + (MCT), chymase + (MCC) and both chymase and tryptase + (MCTC). The mean MCT, MCC, and MCTC numbers in the chronic mastitis group were found to be significantly higher than the control (P < 0.001 for all three phenotypes) but did not differ significantly between control and acute mastitis samples. When the mean numbers of MCT, MCC, and MCTC in the control group and chronic mastitis group were compared, a 10.5, 7.8, and a 4.1-fold increase was observed, respectively. The amount of connective tissue was strongly increased in tissues with chronic mastitis and a 3.01-fold increase was detected compared to the control group. A statistically significant relation was also found between the amount of fibrosis and the increased number of total MCs (P < 0.001).

A mimicker of inflammatory breast carcinoma: Lupus mastitis and evolving imaging features

Rare case of lupus mastitis in a 58-year-old female with discoid lupus erythematosus presented with fever, left breast swelling, and painful palpable lesion. Accurate imaging and histopathologic evaluation allowed for appropriate management and regression of breast findings with hydroxychloroquine treatment, emphasizing the need to avoid unnecessary biopsies and surgeries.

A Retrospective Analysis of the Clinicopathological Features of Patients with Tuberculous Mastitis: A Single Institution's Experience

INTRODUCTION

Tuberculosis remains a global health burden, especially in low- and middle-income countries. Breast tuberculosis is a rare disease with minimal research available. This disease produces a diagnostic challenge as the clinical presentation is variable, and diagnosis often requires additional investigations. This study was undertaken to determine the efficacy of cytology and histology, together with ancillary studies, in diagnosing tuberculous mastitis.

METHODS

This retrospective study was conducted in a Johannesburg Hospital over 5 years. Thirty-two patients with confirmed tuberculous mastitis were included. The patients were considered positive for tuberculous mastitis if histological or cytological findings were confirmed with either a positive tuberculosis culture, Ziehl-Neelsen stain, or polymerase chain reaction examination/GeneXpert.

RESULTS

This case series comprises 3 males and 29 females with a mean age of 35.66. A breast mass was the most common presentation. Over these 5 years, more biopsies were performed on inflammatory breast lesions than fine needle aspirations. There was a higher confirmation rate for cytology diagnoses compared to histology diagnoses.

CONCLUSION

This study supports using fine needle aspiration combined with GeneXpert as the primary diagnostic modality in diagnosing tuberculous mastitis. This test combination is advantageous in resource- and financially constrained environments as it is relatively simple to perform, cost-effective, and has a rapid turnaround time.

Lupus mastitis and antiphospholipid syndrome treated with anticoagulation and immunosuppression: a case report

BACKGROUND

Systemic lupus erythematosus is an autoimmune disease that can have cutaneous and systemic manifestations. Lupus panniculitis, also known as lupus mastitis, is a subset of chronic cutaneous lupus erythematosus that involves inflammation of the subcutaneous fat. The pathogenesis of lupus mastitis is not fully understood. Diagnosis involves a combination of skin manifestations, imaging, and pathologic confirmation. Treatment typically includes steroids and antimalarials, with more severe disease requiring additional immunosuppressive medications. This report highlights a case of lupus mastitis treated with rituximab and a possible relationship between this disease process and thrombotic disease.

CASE PRESENTATION

A 48-year-old African American female with systemic lupus erythematosus and antiphospholipid syndrome presented with new breast lesion. Mammography revealed calcifications and increased density with coarse trabecular pattern. Breast biopsy showed features of cutaneous lupus and occlusive vasculopathy. The patient was diagnosed with lupus mastitis and treated with anticoagulation, rituximab, mycophenolate mofetil, and quinacrine with resolution of her symptoms.

CONCLUSION

This patient experienced improvement in her breast symptoms with combination therapy including rituximab. There are only two other cases reported in literature of patients with lupus mastitis responding to rituximab, highlighting the possible role of B cell depleting therapy for those who have contraindications to standard treatments for lupus mastitis. While the pathophysiology of lupus mastitis is thought to be immune driven, some literature suggests that associated thrombosis commonly seen may be due to a physiologic overlap similar to antiphospholipid syndrome. The possible relationship between antiphospholipid syndrome and lupus mastitis and the use of antiplatelet and anticoagulation therapy is discussed and may warrant further investigation.

LC/MS-based untargeted lipidomics reveals lipid signatures of nonpuerperal mastitis

BACKGROUND

Nonpuerperal mastitis (NPM) is a disease that presents with redness, swelling, heat, and pain during nonlactation and can often be confused with breast cancer. The etiology of NPM remains elusive; however, emerging clinical evidence suggests a potential involvement of lipid metabolism.

METHOD

Liquid chromatography‒mass spectrometry (LC/MS)-based untargeted lipidomics analysis combined with multivariate statistics was performed to investigate the NPM lipid change in breast tissue. Twenty patients with NPM and 10 controls were enrolled in this study.

RESULTS

The results revealed significant differences in lipidomics profiles, and a total of 16 subclasses with 14,012 different lipids were identified in positive and negative ion modes. Among these lipids, triglycerides (TGs), phosphatidylethanolamines (PEs) and cardiolipins (CLs) were the top three lipid components between the NPM and control groups. Subsequently, a total of 35 lipids were subjected to screening as potential biomarkers, and the chosen lipid biomarkers exhibited enhanced discriminatory capability between the two groups. Furthermore, pathway analysis elucidated that the aforementioned alterations in lipids were primarily associated with the arachidonic acid metabolic pathway. The correlation between distinct lipid populations and clinical phenotypes was assessed through weighted gene coexpression network analysis (WGCNA).

CONCLUSIONS

This study demonstrates that untargeted lipidomics assays conducted on breast tissue samples from patients with NPM exhibit noteworthy alterations in lipidomes. The findings of this study highlight the substantial involvement of arachidonic acid metabolism in lipid metabolism within the context of NPM. Consequently, this study offers valuable insights that can contribute to a more comprehensive comprehension of NPM in subsequent investigations.

TRIAL REGISTRATION

Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine (Number: 2019-702-57; Date: July 2019).

[Breast tuberculosis. Report of two cases]

Two cases of mammary tuberculosis (TB) are presented, one of them with additional pleural and lymph node involvement. Both were HIV-negative, with no history of previous TB, with long-standing breast lesions. Both presented a successful outcome with antituberculosis treatment. Breast TB is a very rare pathology that is difficult to diagnose. The cases are presented to consider their differential diagnosis in patients with chronic mastitis and/or nodular or ulcerated lesions of the breast. Multidisciplinary management is recommended.

Ultrasonic multimodality imaging features and the classification value of nonpuerperal mastitis

OBJECTIVE

To explore the value of ultrasonic multimodality imaging for characterizing nonpuerperal mastitis (NPM) lesions and feasibility of distinguishing different subtypes.

METHODS

Thirty-eight NPM lesions were assessed using conventional ultrasonography (US), strain elastography (SE), and contrast-enhanced ultrasound (CEUS). The lesions were confirmed pathologically and classified as granulomatous lobular mastitis (GLM), plasma cell mastitis (PCM), or nonspecific mastitis (NSM). Furthermore, diagnostic indicators were evaluated. The diagnostic performances of the modalities were compared using the area under the receiver operating characteristic curve (AUC).

RESULTS

The overall morphological features on US differed significantly between the GLM and PCM groups (p = 0.002). Lesion size (≤10 mm) (p = 0.003) and mean SE score (p = 0.001) differed significantly between the PCM and NSM groups. The frequent NPM characteristic on CEUS was hyperenhancement with (or without) increased lesion size; intergroup differences were not significant. Breast Imaging Reporting and Data System > 3 was considered to indicate malignancy; accordingly, the accuracy of US alone, US with CEUS, and US with SE was 10.5%, 21.1%, and 65.8%, respectively. Moreover, the AUC for US with SE for classifying GLM and PCM was 0.616.

CONCLUSION

CEUS cannot accurately classify NPM subtypes, while US and SE are valuable for classification.

Aryl hydrocarbon receptor activation by Lactobacillus reuteri tryptophan metabolism alleviates Escherichia coli-induced mastitis in mice

The intestinal microbiota has been associated with the occurrence and development of mastitis, which is one of the most serious diseases of lactating women and female animals, but the underlying mechanism has not yet been elucidated. Aryl hydrocarbon receptor (AhR) activation by microbiota tryptophan metabolism-derived ligands is involved in maintaining host homeostasis and resisting diseases. We investigated whether AhR activation by microbiota-metabolic ligands could influence mastitis development in mice. In this study, we found that AhR activation using Ficz ameliorated mastitis symptoms, which were related to limiting NF-κB activation and enhancing barrier function. Impaired AhR activation by disturbing the intestinal microbiota initiated mastitis, and processed Escherichia coli (E. coli)-induced mastitis in mice. Supplementation with dietary tryptophan attenuated the mastitis, but attenuation was inhibited by the intestinal microbiota abrogation, while administering tryptophan metabolites including IAld and indole but not IPA, rescued the tryptophan effects in dysbiotic mice. Supplementation with a Lactobacillus reuteri (L. reuteri) strain with the capacity to produce AhR ligands also improved E. coli-induced mastitis in an AhR-dependent manner. These findings provide evidence for novel therapeutic strategies for treating mastitis, and support the role of metabolites derived from the intestinal microbiota in improving distal disease.

Mastitis, a common disease for female during lactation period that could cause a health risk for humans or huge economic losses for animals, is caused by pathogen invasion. However, little is known about how host factors affect mastitis’ progression and outcome. Our previous study found that disrupting the intestinal microbiota exacerbated pathogen-induced mastitis, but the underlying mechanism is unclear. Host cell surface receptors recognize intestinal microbiota-metabolized ligands to mediate downstream signal transduction is the primary manner for microbiota-host interactions. In this study, we determined microbiota-mediated aryl hydrocarbon receptor (AhR) activation alleviated E. coli-induced mastitis in mice. Insufficient AhR ligands production by disrupting the intestinal microbiota contributed to mastitis progression, but compensation host with dietary tryptophan, AhR ligands or probiotic Lactobacillus reuteri protected mice from E. coli-induced mastitis by rescuing AhR activation. Our founding provides direct evidence for a potential strategy for treating mastitis and as a basis for targeting microbiota-host interaction for diseases intervention.

Development and Pathology of the Equine Mammary Gland

An understanding of the anatomy, histology, and development of the equine mammary gland underpins study of the pathology of diseases including galactorrhoea, agalactia, mastitis, and mammary tumour development. This review examines the prenatal development of the equine mammary gland and the striking degree to which the tissue undergoes postnatal development associated with the reproductive cycle. The gland is characterised by epithelial structures arranged in terminal duct lobular units, similar to those of the human breast, supported by distinct zones of intra- and interlobular collagenous stroma. Mastitis and mammary carcinomas are two of the most frequently described equine mammary pathologies and have an overlap in associated clinical signs. Mastitis is most frequently associated with bacterial aetiologies, particularly Streptococcus spp., and knowledge of the process of post-lactational regression can be applied to preventative husbandry strategies. Equine mammary tumours are rare and carry a poor prognosis in many cases. Recent studies have used mammosphere assays to reveal novel insights into the identification and potential behaviour of mammary stem/progenitor cell populations. These suggest that mammospheres derived from equine cells have different growth dynamics compared to those from other species. In parallel with studying the equine mammary gland in order to advance knowledge of equine mammary disease at the interface of basic and clinical science, there is a need to better understand equine lactational biology. This is driven in part by the recognition of the potential value of horse and donkey milk for human consumption, particularly donkey milk in children with 'Cow Milk Protein Allergy'.

Staphylococcus aureus-induced proteomic changes in the mammary tissue of rats: A TMT-based study

Staphylococcus aureus is one of the most important pathogens causing mastitis in dairy cows. The objective of this study was to establish a rat model of mastitis induced by S. aureus infection and to explore changes in the proteomes of mammary tissue in different udder states, providing a better understanding of the host immune response to S. aureus mastitis. On day 3 post-partum, 6 rats were randomly divided into two groups (n = 3), with either 100 μL of PBS (blank group) or a S. aureus suspension containing 2×10⁷ CFU·mL⁻¹ (challenge group) infused into the mammary gland duct. After 24 h of infection, the rats were sacrificed, and mammary gland tissue was collected. Tandem mass tag (TMT)-based technology was applied to compare the proteomes of healthy and mastitic mammary tissues. Compared with the control group, the challenge group had 555 proteins with significant differences in expression, of which 428 were significantly upregulated (FC>1.2 and p<0.05) and 127 were downregulated (FC>0.83 and p<0.05 or p<0.01). Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses revealed that upregulated differentially significant expressed proteins (DSEPs) were associated with mainly immune responses, including integrin alpha M, inter-α-trypsin inhibitor heavy chain 4, and alpha-2-macroglobulin. This study is the first in which a rat model of S. aureus-induced mastitis was used to explore the proteins related to mastitis in dairy cows by TMT technology, providing a model for replication of dairy cow S. aureus-induced mastitis experiments.

1,25-hydroxyvitamin D3 decreases endoplasmic reticulum stress-induced inflammatory response in mammary epithelial cells

Recent studies indicated that intramammary administration of active vitamin D₃ hormone (1,25D₃) inhibits the inflammatory process associated with mastitis. We hypothesized that attenuation of endoplasmic reticulum (ER) stress by 1,25D₃ in mammary epithelial cells (MECs) is an important cellular mechanism contributing to this beneficial effect of intramammary treatment with 1,25D₃. To test this hypothesis, the effect of 1,25D₃ was studied on induction of ER stress in a transformed human MEC line, MCF-7 cells. Treatment with two different ER stress inducers, thapsigargin (TG) and tunicamycin (TM), caused a dose-dependent induction of ER stress as evident from up-regulation of protein kinase RNA-like ER kinase (PERK), heat shock protein family A (Hsp70) member 5 (HSPA5), activating transcription factor (ATF4), ATF6, DNA damage inducible transcript 3 (DDIT3) and spliced X-box binding protein 1 (sXBP1) and impaired cell viability and decreased expression of vitamin D receptor (VDR) in MCF-7 cells (P < 0.05). Treatment with 1,25D₃ (100 nM) inhibited TG (10 nM)- and TM (1 μg/mL)-induced mRNA and/or protein levels of ATF4, ATF6, DDIT3 and HSPA5 in MCF-7 cells (P < 0.05). In addition, 1,25D₃ (100 nM) antagonized the effect of TG (10 nM) and TM (1 μg/mL) on mRNA and protein levels of VDR and mRNA levels of genes involved in production and degradation of 1,25D₃ in MCF-7 cells (P < 0.05). Moreover, 1,25D₃ (100 nM) inhibited nuclear factor-κB (NF-κB) activation in response to TM (10 nM) and TG (1 μg/mL) in MCF-7 cells. In conclusion, the present findings show that 1,25D₃ is effective in attenuating ER stress and the NF-κB-driven inflammatory response in MCF-7 cells. This indicates that attenuation of ER stress by 1,25D₃ in MECs may contribute to the recently observed inhibitory effect of intramammary treatment of dairy cows with 1,25D₃ on the inflammatory process associated with mastitis.

Combining ultrasonography and mammography to improve diagnostic accuracy of plasma cell mastitis

OBJECTIVE

To evaluate the diagnostic value of ultrasonography and mammography for plasma cell mastitis.

METHODS

The ultrasonographic and mammographic images of 111 women with histopathologically confirmed plasma cell mastitis were retrospectively analyzed. The diagnostic accuracy of the two imaging methods was compared.

RESULTS

Ultrasonography identified 91 out of 111 (82.0%) patients with plasma cell mastitis, while the other twenty (18.0%) patients were misdiagnosed. Mammography identified 83 (74.8%) out of 111 patients with plasma cell mastitis. Nineteen (17.1%) patients were misdiagnosed. There was no significant difference between the diagnostic accuracy of using two imaging tests (P = 0.127). Mammography clouds identified 11 out of 20 patients who were not diagnosed by ultrasonography. Meanwhile, 19 of the 28 cases misdiagnosed with mammography were correctly identified by ultrasonography. Overall, 91.9% (102/111) of the patients were identified by the combination of ultrasonography and mammography, which yielded statistically significant higher accuracy than using each single test only (P < 0.05).

CONCLUSIONS

In diagnosis of plasma cell mastitis, high-frequency ultrasonography and mammography should be combined to improve the diagnostic accuracy.

Subclinical Mastitis in a European Multicenter Cohort: Prevalence, Impact on Human Milk (HM) Composition, and Association with Infant HM Intake and Growth

Background: Subclinical mastitis (SCM) is an inflammatory condition of the mammary gland. We examined the effects of SCM on human milk (HM) composition, infant growth, and HM intake in a mother–infant cohort from seven European countries. Methods: HM samples were obtained from 305 mothers at 2, 17, 30, 60, 90, and 120 days postpartum. SCM status was assessed using HM Sodium (Na): Potassium (K) ratio >0.6. Levels of different macro- and micronutrients were analyzed in HM. Results: SCM prevalence in the first month of lactation was 35.4%. Mean gestational age at delivery was lower and birth by C-section higher in SCM mothers (p ≤ 0.001). HM concentrations of lactose, DHA, linolenic acid, calcium, and phosphorous (p < 0.05 for all) was lower, while total protein, alpha-lactalbumin, lactoferrin, albumin, arachidonic acid to DHA ratio, n-6 to n-3 ratio and minerals (iron, selenium, manganese, zinc, and copper) were higher (p < 0.001 for all) in mothers with SCM. There were no differences in infant growth and HM intake between non-SCM and SCM groups. Conclusion: We document, for the first time, in a large European standardized and longitudinal study, a high prevalence of SCM in early lactation and demonstrate that SCM is associated with significant changes in the macro- and micronutrient composition of HM. Future studies exploring the relation of SCM with breastfeeding behaviors and developmental outcomes are warranted.

Schisandrin A protects against lipopolysaccharide-induced mastitis through activating Nrf2 signaling pathway and inducing autophagy

Schisandrin A (Sch A), a dibenzocyclooctadiene lignan extracted from Schisandra chinensis (Turcz.) Baill., has anti-oxidant and anti-inflammatory effects, but the effect on masitits has not been studied. Therefore, we investigated the effect of Sch A in cell and mouse models of lipopolysaccharide (LPS)-induced mastitis. Studies in vivo showed that Sch A reduced LPS-induced mammary injury and the production of pro-inflammatory mediators. Sch A also decreased the levels of pro-inflammatory mediators and activated nuclear factor-E2 associated factor 2 (Nrf2) signaling pathway in mouse mammary epithelial cells (mMECs). The Nrf2 inhibitor partially abrogated the downregulation of Sch A on LPS-induced inflammatory response. In addition, LPS stimulation suppressed autophagy, while both Sch A and the autophagy inducer rapamycin activated autophagy in mMECs, which down-regulated inflammatory response. Sch A also restrained LPS-induced phosphorylation of mammalian target of rapamycin (mTOR) and activated AMP-activated protein kinase (AMPK) and unc-51 like kinase 1 (ULK1). In summary, these results suggest that Sch A exerts protective effects in LPS-induced mastitis models by activating Nrf2 signaling pathway and inducing autophagy and the autophagy is initiated by suppressing mTOR signaling pathway and activating AMPK-ULK1 signaling pathway.

Selenium Attenuates Staphylococcus aureus Mastitis in Mice by Inhibiting the Activation of the NALP3 Inflammasome and NF-κB/MAPK Pathway

Mastitis is one of the most important diseases affecting the dairy industry in the world, and it also poses a great threat to human food safety. In this study, we explored whether selenium can inhibit the activation of the NALP3 inflammasome and NF-κB/MAPK pathway to achieve anti-inflammatory effects. Sixty BALB/c female mice were randomly divided into three groups according to diets of different selenium concentrations (high, normal, and low). After 90 days, mice fed the same selenium concentration were randomly divided into two smaller groups, one of which was inoculated with Staphylococcus aureus and the other injected with saline as a control. Through histopathologic examination staining, western blot, qPCR, and ELISA, the results showed that with increasing selenium concentrations, the expression levels of IL-1β, TNF-α, NALP3, caspase-1, and ASC were decreased in mouse mammary tissue. Therefore, this study revealed that selenium can attenuate S. aureus mastitis by inhibiting the activation of the NALP3 inflammasome and NF-κB/MAPK pathway.

The diagnostic value of MRI multi-parameter combination for breast lesions with ring enhancement

PURPOSE

To investigate the diagnostic value of MRI multi-parameter combination for breast lesions with ring enhancement (internal enhancement pattern) on dynamic contrast-enhanced (DCE)-MRI.

METHODS

149 patients with histologically confirmed breast lesions underwent DCE-MRI and diffusion-weighted imaging (DWI) examinations were analyzed. Sixty-seven lesions were found and were allocated into the benign group and the malignant group. The pathological results were used as dependent variables, indexes with statistical differences were used as independent variables, and logistic regression model was performed to construct the newly combined parameters and to evaluate the diagnostic efficacy of the stepwise combined parameters.

RESULTS

There were significant differences in the number of cases with different wall shapes concerning "enhanced ring" and the number of cases with wall nodules between the benign and the malignant group. Significant differences were found in the number of cases with different distribution locations of limited diffusion on DWI between the benign and the malignant group. There were significant differences in the semi-quantitative parameters including early enhancement ratio (EER) and maximum enhancement time (Tmax) between the benign group and the malignant group. There were significant differences in apparent diffusion coefficient (ADC) ring inner and ADC ring wall between the benign and the malignant group. The maximum Youden index of a newly-constructed parameter combination: morphological indexes of "enhanced ring" + distribution locations of limited diffusion on DWI + Tmax + ADC ring inner was 0.732 for combined diagnosis, the area under the ROC curve (Az) was 0.887, and the diagnostic sensitivity and specificity were 85.78 and 87.37%, respectively.

CONCLUSIONS

MRI multi-parameter combination can improve the diagnostic efficacy of breast lesions with ring enhancement.

Postpartum uterine infection & ovarian dysfunction

Postpartum uterine infections such as metritis, endometritis and mastitis have been considered as underlying causes for ovarian dysfunction in mammals. Almost all mammals, particularly dairy animals are susceptible to postpartum uterine infections, resulting in impaired fertility and economic loss. One of the factors for low fertility in females is ovarian dysfunction, which is exhibited as impaired growth and function of ovarian follicles by the postpartum infection. Immune system of mammals provides a host defence mechanism against pathogenic microbes through the recognition of pathogen-associated molecular patterns (PAMPs) and forming inflammasomes. Like immune cells, ovarian granulosa cells also exhibit a similar pattern of cytokine gene expressions on exposure to PAMPs. Genome-wide transcriptomic approaches explored the molecular mechanisms underlying the immune function of buffalo granulosa cells during endotoxin exposure. Understanding the molecular mechanism of ovarian dysfunction due to uterine infection would be helpful to implement various strategies to handle the adverse effects of postpartum uterine disease on fertility by developing potential therapeutics. Therefore, this article focuses on key factors that are responsible for postpartum infection and particularly summarizes the molecular mechanism of infection underlying the ovarian dysfunction in dairy animals.

Mastitis associated with Sjögren's syndrome: a series of nine cases

Sjögren's syndrome is well known to target exocrine glands, especially lacrimal and salivary glands, which share with mammary glands anatomical, histological, and immunological features. Herein, we investigated the mammary involvement in patients with Sjögren's syndrome and compared the histological findings with minor salivary gland involvement. We reviewed the charts of patients with Sjögren's syndrome (followed in Montpellier University Hospital, between January 2000 and January 2015), in whom minor salivary gland and mammary tissues were available. Two expert pathologists analysed retrospectively these tissues in order to identify inflammatory patterns. Immunohistochemical stainings were performed to precise leucocyte distribution. Sixteen Sjögren's syndrome patients with available salivary and breast tissue samples were included. All were women, with a median age of 60.1 ± 11.3 years at Sjögren's syndrome diagnosis. Mammary biopsy was conducted because of breast symptoms in 6 patients and following imaging screening strategies for breast cancer in 10 patients. Nine patients exhibited an inflammatory breast pattern (lymphocytic infiltrates or duct ectasia), close to minor salivary gland histological findings. Immunohistochemical stainings (n = 5) revealed B and T cell infiltrates within breast tissue, with a higher proportion of T CD4+ cells, but no IgG4-secreting plasma cells were found. This is the first series to describe breast inflammatory patterns in Sjögren's syndrome. Mastitis is in line with the classical involvement of exocrine glands in this disease. These findings are consistent with the literature data considering Sjögren's syndrome as an "autoimmune epithelitis".

Infectious and Inflammatory Breast Disease

Breast inflammation can signal an array of breast conditions, from difficulties with breastfeeding to a rare and aggressive type of breast cancer. In some cases, these diseases resemble each other clinically and on imaging examinations. This article explains the inflammatory process and discusses a variety of localized benign inflammatory breast diseases, including lactational and nonlactational mastitis, ductal ectasia, idiopathic granulomatous mastitis, fat necrosis, and diabetic mastopathy. Inflammatory breast cancer also is presented, with an emphasis on its signs and symptoms, diagnosis, staging, multimodality treatment, and prognosis.

Hardness and Painful Lesion of the Breast

Dear Editor, Lupus panniculitis or lupus profundus is a rare inflammatory complication found in patients with systemic lupus erythematosus (SLE), or discoid lupus erythematosus (DLE) (1). When the breast is involved, the term lupus mastitis (LM) is used. This disease involving the breast is rare, and the lesions may precede, coincide with, or occur later than the onset of other lupus lesions. Tissue biopsy is required to confirm the suspected diagnoses of LM. We report a case of a patient with lupus mastitis due to the important differential diagnosis. A 60-year-old woman presented with a painful nodular lesion in her left breast that had appeared 15 days ago (Figure 1, a). She had been previously diagnosed with discoid lupus erythematosus 3 years ago. Physical examination revealed a deep and firm erythematous subcutaneous nodule without overlying skin involvement in the lower-central portion of the left breast. Laboratory findings were positive for antinuclear antibodies (1:80) and double-stranded deoxynucleic acid antibodies (1:10). Mammography and ultrasounds showed an area of increased density and irregular breast tissue along with an important thickening of the overlying skin (Figure 1, b). On suspicion of malignancy, a needle biopsy of the breast lesion was performed and showed vacuolar alteration and lymphocytic infiltrate in the basal layer. Subcutaneous fat showed a lobular panniculitis with a prominent lymphocytic infiltrate and hyalinization of the fat lobules (hyaline fat necrosis). Direct immunofluorescence of the face biopsy revealed IgA, IgG, IgM, and C3 granular deposition. Based on these results, a diagnosis of lupus mastitis associated with DLE was established. Antimalarial therapy resulted in complete resolution of the clinical features. Three years later, the patient presented with a disfiguring atrophy with retraction in the damaged areas of the breast (Figure 2). Lupus mastitis is a very unusual disease that most commonly affects middle-aged women. The first case of LM was described by Tuffanelli in 1971. The lesions usually present following the diagnosis of SLE/DLE; however, on rare occasions they may be observed earlier (2). The histophysiology of this disease remains unclear, but the predominant theory suggests an autoimmune-related etiology. Corroborating evidence for this theory includes the finding of immune complexes, both at the basement membrane of the dermal-epidermal junction and in the blood vessels in the areas of panniculitis (3). Lupus mastitis may be present in the breast as single or multiple subcutaneous nodules that may be tender or painful and can progress to chronic ulcers over time or resolve, leaving atrophic scars. The overlying skin can be normal, erythematous, poikilodermic or ulcerated. When skin changes are prominent, the lesion may clinically and radiologically mimic inflammatory breast carcinoma. Mammographic and ultrasounds findings include an ill-defined breast density with or without associated microcalcifications (4). Histologically, this disease is characterized by lobular lymphocytic panniculitis and predominantly involves the fat lobule and the presence of anucleated adipocytes in a background of a glassy-appearing collagenous stroma (hyaline fat necrosis). Fibrinoid necrosis of the vessel wall has also been reported, but is usually absent (5). Differential diagnosis of lupus mastitis includes inflammatory breast carcinoma, primary medullary carcinoma, and other immune-mediated inflammatory conditions such as diabetic mastopathy. The first line of treatment the use of antimalarial drugs such as hydroxychloroquine. Systemic steroids and cyclophosphamide have also been used. Surgical treatment should be considered only in patients who do not respond to management with medications. In summary, we reported a case of lupus mastitis in a patient with discoid lupus erythematosus. This dermatosis should be considered in the differential diagnosis of breast lesions in lupus patients, and a biopsy of the breast lesion is essential to reject suspected malignancy. If the disease is left untreated, unsightly atrophy will appear; it is thus important to diagnose early on. The course of the disease tends to be chronic with remission and flares, so patients should be followed-up regularly due to the risk of recurrences in the same area or in a different location.

ANGPTL3 is part of the machinery causing dyslipidemia majorily via LPL inhibition in mastitis mice

Previous investigations have shown that inflammation induces changes in lipid and lipoprotein metabolism, and increased expression of angiopoietin-like protein 3 (ANGPTL3) contributes to the development of dyslipidemia. Here we investigated whether there is a correlation between increased ANGPTL3 expression and dyslipidemia in mastitis mice. Thirty mice were divided into two groups: control group and Staphylococcus aureus (S. aureus)-induced mastitis mice group. Changes in the levels of blood lipids [total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C)]; activity of myeloperoxidase (MPO); concentrations of plasma inflammation biomarkers [interferon-γ (IFNγ), tumor necrosis factor α (TNFα), and interleukin-1α (IL-1α)]; concentration of plasma ANGPTL3 protein; lipoprotein lipase (LPL) activities in postheparin plasma; expressions of hepatic N-acetylgalactosaminyltransferase 2 (GALNT2), hepatic ANGPTL3 and adipose LPL were determined. The major results indicated specific pathological mammary tissue changes, elevated MPO activity, reduced GALNT2 mRNA expression, elevated ANGPTL3 mRNA and protein expression and reduced LPL mRNA and protein expression. In plasma samples the S.aureus infused mice displayed elevated ANGPTL3 protein concentration, TG, TC and LDL-C levels, and reduced postheparin LPL activities and HDL-C level. The data suggests that ANGPTL3 is part of the machinery causing dyslipidemia majorily via LPL inhibition in mastitis mice.

A mouse mastitis model to study the effects of the intramammary infusion of a food-grade Lactococcus lactis strain

Lactococcus lactis is one of the most important microorganisms in the dairy industry and has “generally recognized as safe” (GRAS) status. L. lactis belongs to the group of lactic acid bacteria (LAB) and is encountered in a wide range of environments. Recently, the use of the intramammary infusion of a live culture of LAB has been investigated as a new antibiotic alternative for treating mastitis in dairy ruminants. Controversial results are described in literature regarding its efficacy and safety. In this study we conducted in-depth investigation of the mammary gland immune response induced by intramammary inoculum of a live culture of L. lactis LMG 7930 using the mouse mastitis model. Overnight cultures either of L. lactis (≈ 10⁷ CFU) or of the mastitis pathogens Staphylococcus chromogenes (≈ 10⁵ CFU) or S. aureus (≈ 10² CFU/ml) were injected into the mouse inguinal glands. A double injection, consisting of S. chromogenes first and then L. lactis, was also investigated. Bacterial recovery from the gland and inflammatory cell infiltration were assessed. L. lactis-treated and control glands were analysed for proinflammatory cytokine production. Microbiological results showed that L. lactis was able to survive in the mammary gland 24 h post infection, as were the mastitis pathogens S. chromogenes and S. aureus. L. lactis reduced S. chromogenes survival in the glands and increased its own survival ability by coexisting with the pathogen. Histology showed that L. lactis-treated glands presented variable histological features, ranging from undamaged tissue with no inflammatory cell infiltrate to severe PMN infiltrate with focal areas of tissue damage. S. aureus-treated glands showed the most severe histological grade of inflammation despite the fact that the inoculum size was the smallest. In contrast, most S. chromogenes-treated glands showed normal structures with no infiltration or lesions. Significant increases in IL-1β and TNF-α levels were also found in L. lactis-inoculated glands. The above findings seem to suggest that food-grade L. lactis at a high-inoculum dose such as an overnight culture may elicit a suppurative inflammatory response in the mammary gland, thus becoming a potential mastitis-causing pathogen. Because of the unpredictable potential of L. lactis in acting as a potential mastitis pathogen, this organism cannot be considered a safe treatment for bovine mastitis.

Selenium Deficiency Deteriorate the Inflammation of S. aureus Infection via Regulating NF-κB and PPAR-γ in Mammary Gland of Mice

Selenium (Se) is an essential micronutrient contributing to a strong immune system for the prevention of infections and diseases in humans and animals. Dietary Se regulates the immune status and mediates anti-inflammatory action. Mastitis is an inflammation in the mammary gland typically induced through the major pathogen S. aureus. The aim of the present study was to determine the regulating effect of Se on S. aureus-induced inflammation using a mouse mastitis model. Immunofluorescence staining was used to detect histopathological injury. ELISA was used to detect cytokine expression, while protein and mRNA levels were analyzed through Western blotting and qPCR analysis, respectively. The results showed that Se deficiency increased inflammatory lesions in individuals with S. aureus infection in the mammary gland. The NO levels showed a significant increase in Se-deficient mice with S. aureus mastitis. Se deficiency accelerated the production of pro-inflammatory factors and reduced IL-10 expression. Furthermore, the results of the present study showed that the regulating effect of Se on S. aureus-induced mastitis was associated with the NF-κB pathway. Indeed, Se deficiency suppressed PPAR-γ activity and promoted NF-κB pathway activation. Thus, Se supplementation could improve the effect on PPAR-γ and NF-κB. These results suggest that Se deficiency could aggravate the inflammatory injury resulting from S. aureus-induced mastitis. Moreover, the results of the present study contribute to the development of new prevention or treatment methods for S. aureus-induced mastitis and other infectious diseases.

Breast lump as a presentation of a hydatid disease

Hydatid disease is a lesion caused by larval form of Echinococcus granulosus and is seen endemically in sheep-rearing countries. Humans are intermediate hosts of this organism. The liver is the first filter that stops about 75% of the embryos and the lungs filter another 10%, leaving only 15% to develop into cysts in other organs of the body.

Systemic Blastomycosis in a Horse

Progressive multisystemic disease caused by Blastomyces dermatitidis was diagnosed in a 17-year-old Quarter horse broodmare. The mare had been treated unsuccessfully with antibiotics for mastitis 3 months postpartum. The disease progressed to exudative cutaneous lesions affecting the ventrum, pectoral region, and limbs accompanied by weight loss across several months. Yeast bodies were observed in swabs of the cutaneous exudate, suggesting a clinical diagnosis of blastomycosis. Following referral, pleural effusion, cavitated lung lesions, and hyperproteinemia were identified, and the mare was euthanized because of poor prognosis. Necropsy revealed extensive pyogranulomas in the mammary gland, skin, subcutaneous tissues, and lungs, accompanied by thrombi in major blood vessels of the lungs and hind limbs. Histologically, pyogranulomatous inflammation was evident in many tissues, and fungal organisms were seen in sections of mammary gland, skin, subcutis, pericardium, and lung. Blastomyces dermatitidis was cultured from mammary tissue, lungs, lymph node, and an inguinal abscess. Although blastomycosis is endemic in the area of origin of the mare in northwestern Wisconsin, the disease is extremely rare in horses and hence easily misdiagnosed. Unique features of this case included the extent of mammary gland involvement and the presence of thrombi in multiple sites.

Puerarin Exerts an Antiinflammatory Effect by Inhibiting NF-kB and MAPK Activation in Staphylococcus aureus-Induced Mastitis

Mastitis is defined as the inflammation of the mammary gland. There is generally no effective treatment for mastitis in animals. Puerarin, extracted from Radix puerariae, has been proven to possess many biological activities. The present study aims to reveal the potential mechanism that is responsible for the antiinflammatory action of puerarin in Staphylococcus aureus (S. aureus)-induced mastitis in mice. Histopathological changes showed that puerarin ameliorated the inflammatory injury induced by S. aureus. Quantitative real-time polymerase chain reaction and ELISA analysis indicated that puerarin not only suppressed the production of pro-inflammatory cytokines such as TNF-α, IL-1β, and IL-6 but also promoted the secretion of IL-10. Toll-like receptor 2 (TLR2) is important in the immune defense against S. aureus infection. Research in molecular biology has shown that the expression of TLR2 was inhibited with administration of puerarin. Further studies were performed on NF-kB and mitogen-activated protein kinase signaling pathways using western blot. The results demonstrated that puerarin suppressed phosphorylated IkBα, p65, p38, extracellular signal-regulated kinase 1and 2 (ERK), and c-Jun N-terminal kinase (JNK) in a dose-dependent manner. All of the results suggested that puerarin may be a potential therapy for treating mastitis. Copyright © 2016 John Wiley & Sons, Ltd.

IL-6/STAT3 signaling pathway is activated in plasma cell mastitis

Plasma cell mastitis (PCM), a particular type of mastitis, mainly occurs in females at nonpregnant and nonlactating stages. The infiltration of abundant plasma cells and lymphocytes is the hallmark of the disease. The incidence rate of PCM increased gradually and its pathogenesis remained unclear. In this study, we investigated the expression of IL-6/STAT3 signaling pathway, which is vital not only for the differentiation of plasma cells but also for survival of plasma cells and T lymphocytes, in 30 PCM cases, 10 acute mastitis cases and 10 normal breast tissues by immunohistochemical analysis. IL-6 level was significantly higher in PCM patients than in acute mastitis patients or normal group. The positive rate of IL-6 and p-STAT3 staining in PCM samples was 93.3% (28/30) and 70% (21/30), respectively, and there was a significant positive association between IL-6 and p-STAT3 staining (r=0.408, P=0.025). In PCM group, the rate of nipple retraction was 40% (12/30). Significantly higher IL-6 expression was found in PCM patients with nipple retraction than in other PCM patients. However, no significant difference in IL-6 or p-STAT3 staining was detected between PCM patients experiencing recurrence and other PCM patients. In addition, Bcl-2 level was higher in PCM patients than in acute mastitis patients or normal group, but there was no difference in Bcl-2 immunostaining between PCM patients experiencing recurrence and other PCM patients. These indicate that IL-6/STAT3 signaling is activated in PCM and may play an important role in the pathogenesis of PCM.

Antigen-Specific Mammary Inflammation Depends on the Production of IL-17A and IFN-γ by Bovine CD4+ T Lymphocytes

Intramammary infusion of the antigen used to sensitize cows by the systemic route induces a local inflammation associated with neutrophil recruitment. We hypothesize that this form of delayed type hypersensitivity, which may occur naturally during infections or could be induced intentionally by vaccination, can impact the outcome of mammary gland infections. We immunized cows with ovalbumin to identify immunological correlates of antigen-specific mammary inflammation. Intraluminal injection of ovalbumin induced a mastitis characterized by a prompt tissue reaction (increase in teat wall thickness) and an intense influx of leukocytes into milk of 10 responder cows out of 14 immunized animals. The magnitude of the local inflammatory reaction, assessed through milk leukocytosis, correlated with antibody titers, skin thickness test, and production of IL-17A and IFN-γ in a whole-blood antigen stimulation assay (WBA). The production of these two cytokines significantly correlated with the magnitude of the milk leukocytosis following the ovalbumin intramammary challenge. The IL-17A and IFN-γ production in the WBA was dependent on the presence of CD4+ cells in blood samples. In vitro stimulation of peripheral blood lymphocytes with ovalbumin followed by stimulation with PMA/ionomycin allowed the identification by flow cytometry of CD4+ T cells producing either IL-17A, IFN-γ, or both cytokines. The results indicate that the antigen-specific WBA, and specifically IL-17A and IFN-γ production by circulating CD4+ cells, can be used as a predictor of mammary hypersensitivity to protein antigens. This prompts further studies aiming at determining how Th17 and/or Th1 lymphocytes modulate the immune response of the mammary gland to infection.

Baicalein attenuates inflammatory responses by suppressing TLR4 mediated NF-κB and MAPK signaling pathways in LPS-induced mastitis in mice

Baicalein is a phenolic flavonoid presented in the dry roots of Scutellaria baicalensis Georgi. It has been reported that baicalein possesses a number of biological properties, such as antiviral, antioxidative, anti-inflammatory, antithrombotic, and anticancer properties. However, the effect of baicalein on mastitis has not yet been reported. This research aims to detect the effect of baicalein on lipopolysaccharide (LPS)-induced mastitis in mice and to investigate the molecular mechanisms. Baicalein was administered intraperitoneally 1h before and 12h after LPS treatment. The results indicated that baicalein treatment markedly attenuated the damage of the mammary gland induced by LPS, suppressed the activity of myeloperoxidase (MPO) and the levels of tumor necrosis factor (TNF-α) and interleukin (IL-1β) in mice with LPS-induced mastitis. Besides, baicalein blocked the expression of Toll-like receptor 4 (TLR4) and then suppressed the phosphorylation of nuclear transcription factor-kappaB (NF-κB) p65 and degradation inhibitor of NF-κBα (IκBα) and, and inhibited the phosphorylation of p38, extracellular signal-regulated kinase (ERK) and c-jun NH2-terminal kinase (JNK) in mitogen-activated protein kinase (MAPK) signal pathway. These findings suggested that baicalein may have a potential prospect against mastitis.

Transition diseases in grazing dairy cows are related to serum cholesterol and other analytes

The objectives of this study were to describe the incidence of postpartum disease and to evaluate the association with serum cholesterol concentrations during the first 3 weeks after calving in grazing dairy cows. The association between non-esterified fatty acids (NEFA), β-hydroxybutyrate (BHBA), calcium and postpartum diseases was also evaluated. A total of 307 Holstein dairy cows from 6 commercial grazing herds in Osorno, Chile, were monitored from calving until 21 days in milk. Cases of retained placenta, clinical hypocalcemia and clinical mastitis were recorded by the farmer using established definitions. Twice weekly, cows were evaluated for metritis by the same veterinarian based on vaginal discharge and body temperature. Postpartum blood samples were collected weekly and analyzed for serum concentrations of cholesterol, NEFA, BHBA and calcium. Cows were considered as having subclinical ketosis if BHBA >1.2 mmol/L, and subclinical hypocalcemia if calcium <2.0 mmol/L in any of the 3 weekly samples. Overall, 56% of the cows studied developed at least one clinical or subclinical disease after calving. Incidence of individual diseases was 8.8% for retained placenta, 4.2% for clinical hypocalcemia, 11.7% for clinical mastitis, 41.1% for metritis, 19.9% for subclinical hypocalcemia and 16.6% for subclinical ketosis. Lower postpartum cholesterol in cows was associated with developing severe metritis or having more than one clinical disease after calving. For every 0.4 mmol/L decrease in serum cholesterol cows were nearly twice as likely to be diagnosed with multiple clinical diseases after calving. Higher BHBA concentrations and lower calcium concentrations during week 1 were associated with severe cases of metritis. Low serum calcium concentration during week 1 was also associated with developing more than one clinical disorder after calving. In conclusion, the incidence of postpartum diseases can be high even in grazing herds and lower serum cholesterol concentrations were associated with occurrence of clinical postpatum disorders.

Non-classical proIL-1beta activation during mammary gland infection is pathogen-dependent but caspase-1 independent

Infection of the mammary gland with live bacteria elicits a pathogen-specific host inflammatory response. To study these host-pathogen interactions wild type mice, NF-kappaB reporter mice as well as caspase-1 and IL-1beta knockout mice were intramammarily challenged with Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). The murine mastitis model allowed to compare the kinetics of the induced cytokine protein profiles and their underlying pathways. In vivo and ex vivo imaging showed that E. coli rapidly induced NF-kappaB inflammatory signaling concomitant with high mammary levels of TNF-alpha, IL-1 alpha and MCP-1 as determined by multiplex analysis. In contrast, an equal number of S. aureus bacteria induced a low NF-kappaB activity concomitant with high mammary levels of the classical IL-1beta fragment. These quantitative and qualitative differences in local inflammatory mediators resulted in an earlier neutrophil influx and in a more extensive alveolar damage post-infection with E. coli compared to S. aureus. Western blot analysis revealed that the inactive proIL-1beta precursor was processed into pathogen-specific IL-1beta fragmentation patterns as confirmed with IL-1beta knockout animals. Additionally, caspase-1 knockout animals allowed to investigate whether IL-1beta maturation depended on the conventional inflammasome pathway. The lack of caspase-1 did not prevent extensive proIL-1beta fragmentation by either of S. aureus or E. coli. These non-classical IL-1beta patterns were likely caused by different proteases and suggest a sentinel function of IL-1beta during mammary gland infection. Thus, a key signaling nodule can be defined in the differential host innate immune defense upon E. coli versus S. aureus mammary gland infection, which is independent of caspase-1.

Liver X receptor agonist prevents LPS-induced mastitis in mice

Liver X receptor-α (LXR-α) which belongs to the nuclear receptor superfamily, is a ligand-activated transcription factor. Best known for its ability to regulate lipid metabolism and transport, LXRs have recently also been implicated in regulation of inflammatory response. The aim of this study was to investigate the preventive effects of synthetic LXR-α agonist T0901317 on LPS-induced mastitis in mice. The mouse model of mastitis was induced by injection of LPS through the duct of mammary gland. T0901317 was injected 1h before and 12h after induction of LPS intraperitoneally. The results showed that T0901317 significantly attenuated the infiltration of neutrophilic granulocytes, and the activation of myeloperoxidase (MPO); down-regulated the level of pro-inflammatory mediators including TNF-α, IL-1β, IL-6, COX-2 and PEG2; inhibited the phosphorylation of IκB-α and NF-κB p65, caused by LPS. Moreover, we report for the first time that LXR-α activation impaired LPS-induced mastitis. Taken together, these data indicated that T0901317 had protective effect on mastitis and the anti-inflammatory mechanism of T0901317 on LPS induced mastitis in mice may be due to its ability to inhibit NF-κB signaling pathway. LXR-α activation can be used as a therapeutic approach to treat mastitis.

Caloric restriction reverses obesity-induced mammary gland inflammation in mice

Obesity is a risk factor for the development of hormone receptor-positive breast cancer in postmenopausal women. Estrogen synthesis is catalyzed by aromatase. Recently, we identified an obesity→inflammation→aromatase axis in mouse models and women. In mouse models of obesity, inflammatory foci characterized by crown-like structures (CLS) consisting of dead adipocytes encircled by macrophages were found in the mammary gland. CLS of the breast were found in most overweight and obese women. CLS were associated with adipocyte hypertrophy, activation of NF-κB, elevated levels of proinflammatory mediators and aromatase, and increased expression of the progesterone receptor (PR). Collectively, these findings provide a plausible explanation for the link between obesity, chronic inflammation, and postmenopausal breast cancer. Here, we investigated whether caloric restriction (CR) reversed the inflammatory state and related molecular changes in the mammary gland of obese mice. Obese ovariectomized C57BL/6J mice were subjected to 30% CR for 7 or 14 weeks. Findings in CR mice were compared with the results in mice fed a high-fat diet ad libitum or with control mice fed a low-fat diet. CR was associated with more than a 75% decrease in mammary CLS/cm(2). Reduced histologic inflammation following CR was associated with decreased adipocyte diameter and monocyte chemoattractant protein-1 (MCP-1) levels, reduced NF-κB binding activity, and normalization of levels of proinflammatory mediators, aromatase, and PR. In summary, obesity-related inflammation of the mammary gland and elevated aromatase and PR levels were reversed with CR. Our results provide a rationale for determining whether weight loss can reverse breast inflammation associated with obesity in women.

Breast inflammation in type 1 diabetes

BACKGROUND

Lymphocytic mastitis is an uncommon fibroinflammatory disease of the breast which occurs in patients with longstanding diabetes. Various imaging patterns in mammography, ultrasound and magnetic resonance imaging (MRI) have been widely described. This communication wishes to provide some explanation to the variation of imaging findings by a study of follow-up cases and present young nonlactating women who had abscess as the first clinical manifestation of type 1 diabetes.

METHODS

Five women with pathologically confirmed lymphocytic mastopathy and 8 women with type 1 diabetes who presented with breast abscess at National Guard Hospital, Riyadh were studied. The ultrasound, mammographic and MRI features were analyzed. Follow-up of 2 to 4 years was done. The clinical findings were analyzed in a descriptive way.

RESULTS

A total of 13 women were studied. Age ranged from 22-54 years. The clinical presentation was a painless hard breast mass in the 5 cases with lymphocytic mastitis and painful mass in 8 women with breast abscess, 3 of which were non-lactating young women. The common imaging finding at mammography was diffuse or focal stromal distortion unilaterally or bilaterally in 4 cases (80%). Complete clinical and mammographic resolution occurred in 2 (40%) of the cases while it was only partial in the rest with lymphocytic mastopathy. Initial ultrasound showed stromal changes in 3 (60%), mass-like lesion in 1 (20%) and normal in 1 (20%). At follow-up ultrasound examination, all had interval development of dense acoustic shadowing representing the previous lesions between 1-2 years.

CONCLUSION

Lymphocytic mastitis can have various patterns at the initial presentation at ultrasound. However, the chronic change at follow-up in this study was intense acoustic shadowing without any mass in all. Type 1 diabetes is suggested in young non-lactating females presenting with breast abscess.

Feline gangrenous mastitis

A 3.7-kg, 3-year-old intact female domestic shorthaired cat was presented with the chief complaint of anorexia and lethargy of 3 days duration with a noticeable decrease in body condition and a large open wound on her ventral caudal abdomen. A diagnosis of acute mastitis with gland abscessation was made. The patient was successfully treated with oral antibiotics and open wound management using surgical debridement and lavage followed by wound dressings using honey.

[Efficacy of application of radiofrequency scalpel and ozono-ultrasound method in dynamics of planimetric indices of the wound course process in the patients, suffering an acute purulent lactation mastitis]

The results of planimetric investigation, conducted in 82 patients, suffering an acute purulent lactation mastitis (APLM), were analyzed. Of them 42 patients (the main group) were operated on, using radiofrequency scalpel, for the postoperative wounds processing the low-frequency ultrasound and ozonated isotonic solution of sodium chloride were used. In 40 patients (group of comparison) the conventional methods of treatment of APLM were applied.

Tuberculosis of the breast

BACKGROUND

Tuberculosis of the breast is a rare disease with non specific manifestations. It should be included in the differential diagnosis of breast lesions in immune compromised patients especially in tuberculosis endemic areas of the world.

CASE REPORT

We report a case of a 31 year old HIV positive lady who presented with an ulcerated mass on the left breast of 3 months' duration. Incision biopsy of the lesion confirmed tuberculosis of the breast. Treatment with standard anti tuberculous drugs resulted In complete resolution.

CONCLUSION

A high index of suspicion is required to make a diagnosis of breast tuberculosis. The disease can be treated conservatively with standard anti tuberculous drugs while surgery is reserved for rare cases.

[Anti-mycobacteria drugs therapy for periductal mastitis with fistula]

OBJECTIVES

To study the etiology, clinical and pathologic characteristics of periductal mastitis with fistula and estimate the effect of anti-mycobacterial agents for periductal mastitis with fistula.

METHODS

Totally 27 patients of periductal mastitis with fistula received anti-mycobacteria drugs therapy from December 2008 to September 2011 were analyzed retrospectively. All of the patients were female. The mean age at onset was 28 years (range 15 to 40 years old). The main clinical manifestation of the 27 patients was breast fistula, including 21 patients with single fistula and 6 patients with multiple fistula. Three patients manifested with pure fistula, 14 patients with both fistula and lump, 10 patients with fistula, lump and abscess. The samples including pus or tissues of all patients were underwent bacteria culture and all patients core needle biopsy. All patients were given primary anti-mycobacteria drugs therapy, parts of patients received surgery based on the evaluation of medical treatment.

RESULTS

The common bacteria culture of all patients failed to demonstrate any causative microorganism. Four cases were selected randomly to undergo PCR of mycobacteria, only one case was identified as Massiliense in bacteria culture of mycobacteria. Twenty-seven patients with periductal mastitis with fistula were treated with anti-mycobacterial agents (isoniazid, rifampicin and ethambutol or pyrazinamide of triple oral drugs) for 1 to 3 months, the fistula of all 27 patients were closed well. Sixteen patients were treated with the agents only and cured. Eleven patients received surgical treatment after treated with the medical agents. None of the patients were given mastectomy. All patients had no reccurence until now.

CONCLUSIONS

The periductal mastitis with fistula has a closely relationship with the infection of nontuberculosis mycobacteria. Those patients could be treated with triple anti-mycobacterial agents and could also avoided mastectomy.

Bap, a biofilm matrix protein of Staphylococcus aureus prevents cellular internalization through binding to GP96 host receptor

The biofilm matrix, composed of exopolysaccharides, proteins, nucleic acids and lipids, plays a well-known role as a defence structure, protecting bacteria from the host immune system and antimicrobial therapy. However, little is known about its responsibility in the interaction of biofilm cells with host tissues. Staphylococcus aureus, a leading cause of biofilm-associated chronic infections, is able to develop a biofilm built on a proteinaceous Bap-mediated matrix. Here, we used the Bap protein as a model to investigate the role that components of the biofilm matrix play in the interaction of S. aureus with host cells. The results show that Bap promotes the adhesion but prevents the entry of S. aureus into epithelial cells. A broad analysis of potential interaction partners for Bap using ligand overlayer immunoblotting, immunoprecipitation with purified Bap and pull down with intact bacteria, identified a direct binding between Bap and Gp96/GRP94/Hsp90 protein. The interaction of Bap with Gp96 provokes a significant reduction in the capacity of S. aureus to invade epithelial cells by interfering with the fibronectin binding protein invasion pathway. Consistent with these results, Bap deficient bacteria displayed an enhanced capacity to invade mammary gland epithelial cells in a lactating mice mastitis model. Our observations begin to elucidate the mechanisms by which components of the biofilm matrix can facilitate the colonization of host tissues and the establishment of persistent infections.

Percutaneous biopsies: indications and techniques

Breast inflammation is a difficult clinical problem as it can result from a variety of causes: specific or non-specific infectious mastitis, which may or may not be complicated, primary or secondary inflammatory mastitis or inflammatory cancer. The main objective of radiology is to eliminate an inflammatory cancer. Other objectives are to characterise an inflammatory condition (where the clinical context is valuable in guiding diagnosis but which often requires a micro- or macrobiopsy) or to obtain a microorganism in cases of complicated infectious mastitis (a diagnostic procedure but also comprising the first stage of treatment). Whether for bacteriological or histological purposes, percutaneous samples therefore play a large part in the diagnostic procedure, other than in the clinical context of pregnancy where mastitis is more easily diagnosed because of its frequency. The guidance method is usually ultrasound, and the needle chosen will depend on the radiological or ultrasound signal: puncture with an 18G needle will be used for a bacteriological sample, microbiopsy of a mass or lymph nodes, or macrobiopsy in the case of microcalcifications.

Immunopathology of mastitis: insights into disease recognition and resolution

Mastitis is an inflammation of the mammary gland commonly caused by bacterial infection. The inflammatory process is a normal and necessary immunological response to invading pathogens. The purpose of host inflammatory responses is to eliminate the source of tissue injury, restore immune homeostasis, and return tissues to normal function. The inflammatory cascade results not only in the escalation of local antimicrobial factors, but also in the increased movement of leukocytes and plasma components from the blood that may cause damage to host tissues. A precarious balance between pro-inflammatory and pro-resolving mechanisms is needed to ensure optimal bacterial clearance and the prompt return to immune homeostasis. Therefore, inflammatory responses must be tightly regulated to avoid bystander damage to the milk synthesizing tissues of the mammary gland. The defense mechanisms of the mammary gland function optimally when invading bacteria are recognized promptly, the initial inflammatory response is adequate to rapidly eliminate the infection, and the mammary gland is returned to normal function quickly without any noticeable clinical symptoms. Suboptimal or dysfunctional mammary gland defenses, however, may contribute to the development of severe acute inflammation or chronic mastitis that adversely affects the quantity and quality of milk. This review will summarize critical mammary gland defense mechanisms that are necessary for immune surveillance and the rapid elimination of mastitis-causing organisms. Situations in which diminished efficiency of innate or adaptive mammary gland immune responses may contribute to disease pathogenesis will also be discussed. A better understanding of the complex interactions between mammary gland defenses and mastitis-causing pathogens should prove useful for the future control of intramammary infections.

Direct and indirect measurement of somatic cell count as indicator of intramammary infection in dairy goats

BACKGROUND

Mastitis is the most important and costly disease in dairy goat production. Subclinical mastitis is common in goats and is mainly caused by contagious bacteria. Several methods to diagnose subclinical mastitis are available. In this study indirect measurement of somatic cell count (SCC) by California Mastitis Test (CMT) and direct measurement of SCC using a portable deLaval cell counter (DCC) are evaluated. Swedish goat farmers would primarily benefit from diagnostic methods that can be used at the farm. The purpose of the study was to evaluate SCC measured by CMT and DCC as possible markers for intramammary infection (IMI) in goats without clinical symptoms of mastitis. Moreover to see how well indirect measurement of SCC (CMT) corresponded to direct measurement of SCC (DCC).

METHOD

Udder half milk samples were collected once from dairy goats (n = 111), in five different farms in Northern and Central Sweden. Only clinically healthy animals were included in the study. All goats were in mid to late lactation at sampling. Milk samples were analyzed for SCC by CMT and DCC at the farm, and for bacterial growth at the laboratory.

RESULTS

Intramammary infection, defined as growth of udder pathogens, was found in 39 (18%) of the milk samples. No growth was found in 180 (81%) samples while 3 (1%) samples were contaminated. The most frequently isolated bacterial species was coagulase negative staphylococci (CNS) (72% of all isolates), followed by Staphylococcus aureus (23% of all isolates). Somatic cell count measured by DCC was strongly (p = 0.000) associated with bacterial growth. There was also a very strong association between CMT and bacterial growth. CMT 1 was associated with freedom of IMI while CMT ≥2 was associated with IMI. Indirect measurement of SCC by CMT was well correlated with SCC measured by DCC.

CONCLUSIONS

According to the results, SCC measured with CMT or DCC can predict udder infection in goats, and CMT can be used as a predictor of the SCC.

[Granulomatous lobular mastitis: a clinicopathologic study of 68 cases]

OBJECTIVE

To study the clinical and pathologic features of granulomatous lobular mastitis (GLM).

METHODS

Sixty-eight cases of GLM were retrieved from the archival file. The clinical data and histologic features were retrospectively reviewed.

RESULTS

Sixty-eight patients presented with breast mass. Ulceration in overlying breast skin was seen in 9 cases. Most of the patients had history of breast feeding. None of them had evidence of specific infections involving the breast. The clinical and radiologic features mimicked malignancy. Histologically, GLM was characterized by the presence of non-necrotizing granulomas, usually admixed with neutrophils and associated with benign ductolobular units. The ductolobular architecture was still preserved. The duration of follow up ranged from 6 to 36 months. Four patients suffered from disease recurrence.

CONCLUSIONS

GLM shows clinical and radiologic features reminiscent of breast cancer. Correct diagnosis requires histologic examination of the biopsy specimens.