Inflammatory responses in brain after cerebral ischemia have been studied extensively in male but not female mice, thus potentially giving a less-than-accurate view of gender-based pathological processes. In humans, cerebral infarcts are typically smaller in premenopausal females than age-matched males. In the current study, we confirmed smaller infarcts in female vs. male mice after middle cerebral artery occlusion and 96 hours of reperfusion. Moreover, we explored immunological alterations related to this difference and found that the percentage of CD4+ T lymphocytes was significantly higher in males than females in spleens with increased expression of the activation markers, CD69 and CD44. In contrast, the percentage of CD8+ T lymphocytes was significantly higher in females than males in spleens, leading to the identification of a small but distinct population of IL-10-secreting CD8+CD122+ T-suppressor cells that were also increased in females. Finally, we observed that males have a greater percentage of activated macrophages/microglia in brain than females, as well as increased expression of the VLA-4 adhesion molecule in both brain and spleen. This new information suggesting gender-dependent immunological mechanisms in stroke implies that effective treatments for human stroke may also be gender specific.

The Agency for Healthcare Research and Quality (ARHQ) patient safety indicators (PSI) were developed as a metric of hospital complication rates. PSI-14 measures postoperative wound dehiscence and specifically how often a surgical wound in the abdominal or pelvic area fails to heal after abdominopelvic surgery. Wound dehiscence is estimated to occur in 0.5–3.4% of abdominopelvic surgeries, and carries a mortality of up to 40%. Postoperative wound dehiscence has been adopted as a surrogate safety outcome measure since it impacts morbidity, length of stay, healthcare costs and readmission rates. Postoperative wound dehiscence cases from the Nationwide Inpatient Sample demonstrate 9.6% excess mortality, 9.4 days of excess hospitalization and $40,323 in excess hospital charges relative to matched controls. The purpose of the current study was to investigate the associations between PSI-14 and measurable medical and surgical co-morbidities by using the Explorys technology platform to query electronic health record (EHR) data from a large hospital system serving a diverse patient population in the Washington DC and Baltimore, MD metropolitan areas. The study population included 25,636 eligible patients who had undergone abdominopelvic surgery between January 1, 2008 and December 31, 2012. Of these cases, 786 (2.97%) had post-operative wound dehiscence. Patient-associated co-morbidities were strongly associated with PSI-14, suggesting that this indicator may not solely be an indicator of hospital safety. There was a strong association between PSI-14 and opioid use after surgery and this finding merits further investigation.

Chronic wounds are wounds that have failed to heal after 3 months of appropriate wound care. Previous reports have identified a diverse collection of bacteria in chronic wounds, and it has been postulated that bacterial profile may contribute to delayed healing. The purpose of this study was to perform a microbiome assessment of the Wound Healing and Etiology (WE-HEAL) Study cohort, including underlying comorbidities less commonly studied in the context of chronic wounds, such as autoimmune diseases, and investigate possible relationships of the wound microbiota with clinical healing trends. We examined chronic wound specimens from 60 patients collected through the WE-HEAL Study using 16S ribosomal RNA gene sequencing. A group of co-occurring obligate anaerobes was identified from taxonomic analysis guided by Dirichlet multinomial mixtures (DMM) modeling. The group includes members of the Gram-positive anaerobic cocci (GPAC) of the Clostridia class (i.e., Anaerococcus, Finegoldia, and Peptoniphilus) and additional strict anaerobes (i.e., Porphyromonas and Prevotella). We showed that the co-occurring group of obligate anaerobes not only co-exists with commonly identified wound species (such as Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas, Corynebacterium, and Streptococcus), but importantly, they could also predominate the wound microbiota. Furthermore, examination of clinical comorbidities of the WE-HEAL specimens showed that specific obligate and facultative anaerobes were significantly reduced in wounds presented with autoimmune disease. With respect to future healing trends, no association with the wound microbiome community or the abundance of individual wound species could be established. In conclusion, we identified a co-occurring obligate anaerobic community type that predominated some human chronic wounds and underrepresentation of anaerobes in wounds associated with autoimmune diseases. Possible elucidation of host environments or key factors that influence anaerobe colonization warrants further investigation in a larger cohort.

It has been demonstrated by us as well as others that eosinophils may alter their phenotype and function based on the local environment (7, 9, 10). Since costimulation plays a critical role in T cell cytokine production and environmental polarization (11, 12), we examined the possibility that eosinophils may lose their tolerogenic properties in the absence of CSB immunosuppression. Cytokine expression was examined in BALB/c (H2 d) lung allografts transplanted into fully MHC-mismatched C57BL/6 (B6) (H2 b) recipient mice. In the absence of immunosuppression, lung allografts had higher levels of Th1-polarizing cytokines IFN-γ and TNF-α than did CSB-treated accepting lung grafts (Figure 1A). Limited amounts of Th2-polarizing cytokines IL-4, IL-13, IL-33, and GM-CSF were evident in lung allografts treated with or without CSB immunosuppression (Supplemental Figure 1A; supplemental material available online with this article; https://doi.org/10.1172/jci.insight.128241DS1). We next evaluated lung-resident eosinophils from both CSB-treated and nonimmunosuppressed grafts. Based on a previously identified eosinophil polarization phenotype (7), we noted higher levels of Th1-defining (or E1-defining) features, such as CXCL9, CXCL10, CXCL11, and iNOS in eosinophils isolated from rejecting compared with CSB-treated lung allografts (Figure 1A). In no group was Th2 (or E2) polarization of eosinophils detected (Supplemental Figure 1A). Flow cytometric characterization demonstrated an absence of MHC II and costimulatory molecules such as CD80, CD86, and CD40. However, there were high levels of recipient-derived MHC I (H2K b), PD-L1, and CD101 on lung-resident eosinophils in the absence of CSB (Figure 1B). Notably, we did not detect BALB/c-derived H2 d-MHC on graft-resident eosinophils, indicating a lack of "cross-dressing" or antigen swapping for donor derived-antigens (ref. 13 and Supplemental Figure 1B). Thus, while eosinophils from rejecting lungs resembled those from accepting lungs in some aspects, we did observe some differences. It is thus possible that in the absence of immunosuppression, eosinophils may contribute to graft rejection rather than acceptance, specifically because CD101 expression has been previously associated with an inflammatory eosinophil subtype (14). In order to evaluate this directly, we conditionally depleted eosinophils from B6 iPHIL mice, in which the diphtheria toxin (DT) receptor is expressed under the control of the eosinophil peroxidase promoter (Supplemental Figure 1C and ref. 15). DT-treated mice or saline-injected controls were challenged with a BALB/c lung allograft in the absence of immunosuppression. Surprisingly, mice depleted of eosinophils had higher grades of rejection (Figure 1C), increased numbers of lung-resident T lymphocytes, increased rates of T cell proliferation, and increased effector cell differentiation by day 4 after engraftment (Figure 1D). These patterns of T lymphocyte activation and infiltration were especially prominent for CD8 + T cells. CD4 + T cell proliferation did ...