Background

Hematologic variables are often analyzed in animal analogs during the investigation of complex disease etiologies such as necrotizing enterocolitis. However, reference intervals (RI) can vary depending on animal strain, age, and sampling site. Reference intervals have been published for adult C57BL/6J mice, but not newborn C57BL/6J mice.

Objectives

The purpose of the present study was to determine hematologic RI in newborn C57BL/6J mice up to day 35.

Methods

C57BL/6J mice founders from The Jackson Laboratory were bred at the University of Iowa. Blood samples were obtained via facial vein sampling at postnatal days 0 (p0), p7, p14, p21, p28, or young adulthood (p35). CBCs were determined with the Sysmex XT-2000iV analyzer within 30 minutes of blood collection at a 1:10 dilution. Statistics were determined using nonparametric methods following ASVCP guidelines.

Results

Hematologic RI were determined for each of the 6 groups (n = 247, n ≥ 39 per group). Significantly higher values for HGB, RBC, and PLT counts were observed with advancing developmental age. Total WBC counts remained relatively stable during the first 35 days of life. However, WBC differential counts were dominated by neutrophils and lymphocytes in the younger mice, with a trend toward a lymphocytic leukogram on day 35.

Conclusions

These results illustrate the dynamic changes in hematologic variables during murine development after birth. Utilization of age-specific RI is advised when evaluating data derived from experimental perinatal mouse models.

Infants with intrauterine growth restriction (IUGR) are at increased risk for neonatal and lifelong morbidities affecting multiple organ systems including the intestinal tract. The underlying mechanisms for the risk to the intestine remain poorly understood. In this study, we tested the hypothesis that IUGR affects the development of goblet and Paneth cell lineages, thus compromising the innate immunity and barrier functions of the epithelium. Using a mouse model of maternal thromboxane A2-analog infusion to elicit maternal hypertension and resultant IUGR, we tested whether IUGR alters ileal maturation and specifically disrupts mucus-producing goblet and antimicrobial-secreting Paneth cell development. We measured body weights, ileal weights and ileal lengths from birth to postnatal day (P) 56. We also determined the abundance of goblet and Paneth cells and their mRNA products, localization of cellular tight junctions, cell proliferation, and apoptosis to interrogate cellular homeostasis. Comparison of the murine findings with human IUGR ileum allowed us to verify observed changes in the mouse were relevant to clinical IUGR. At P14 IUGR mice had decreased ileal lengths, fewer goblet and Paneth cells, reductions in Paneth cell specific mRNAs, and decreased cell proliferation. These findings positively correlated with severity of IUGR. Furthermore, the decrease in murine Paneth cells was also seen in human IUGR ileum. IUGR disrupts the normal trajectory of ileal development, particularly affecting the composition and secretory products of the epithelial surface of the intestine. We speculate that this abnormal intestinal development may constitute an inherent "first hit", rendering IUGR intestine susceptible to further injury, infection, or inflammation.

Background

Both HIV and depression are associated with increased heart failure (HF) risk. Depression, a common comorbidity, may further increase the risk of HF among adults with HIV infection (HIV+). We assessed the association between HIV, depression, and incident HF.

Methods and results

Veterans Aging Cohort Study (VACS) participants free from cardiovascular disease at baseline (n=81 427: 26 908 HIV+, 54 519 without HIV [HIV-]) were categorized into 4 groups: HIV- without major depressive disorder (MDD) [reference], HIV- with MDD, HIV+ without MDD, and HIV+ with MDD. International Classification of Diseases, Ninth Revision codes from medical records were used to determine MDD and the primary outcome, HF. After 5.8 years of follow-up, HF rates per 1000 person-years were highest among HIV+ participants with MDD (9.32; 95% confidence interval [CI], 8.20-10.6). In Cox proportional hazards models, HIV+ participants with MDD had a significantly higher risk of HF (adjusted hazard ratio, 1.68; 95% CI, 1.45-1.95) compared with HIV- participants without MDD. MDD was associated with HF in separate fully adjusted models for HIV- and HIV+ participants (adjusted hazard ratio, 1.21; 95% CI, 1.06-1.37; and adjusted hazard ratio, 1.29; 95% CI, 1.11-1.51, respectively). Among those with MDD, baseline antidepressant use was associated with lower risk of incident HF events (adjusted hazard ratio, 0.76; 95% CI, 0.58-0.99).

Conclusions

Our study is the first to suggest that MDD is an independent risk factor for HF in HIV+ adults. These results reinforce the importance of identifying and managing MDD among HIV+ patients. Future studies must clarify mechanisms linking HIV, MDD, antidepressants, and HF and identify interventions to reduce HF morbidity and mortality in those with both HIV and MDD.