Glucans are immunomodulatory carbohydrates found in the cell walls of fungi and certain bacteria. We examined the pharmacokinetics of three water-soluble glucans (glucan phosphate, laminarin, and scleroglucan) after oral administration of 1 mg/kg doses in rats. Maximum plasma concentrations for glucan phosphate occurred at 4 h. In contrast, laminarin and scleroglucan showed two plasma peaks between 0.5 and 12 h. At 24 h, 27 Ϯ 3% of the glucan phosphate and 20 Ϯ 7% of the laminarin remained in the serum. Scleroglucan was rapidly absorbed and eliminated. The liver did not significantly contribute to the clearance of plasma glucan. Biological effects were further studied in mice. Following oral administration of 1 mg, glucans were bound and internalized by intestinal epithelial cells and gut-associated lymphoid tissue (GALT) cells. Internalization of glucan by intestinal epithelial cells was not Dectindependent. GALT expression of Dectin-1 and toll-like receptor (TLR) 2, but not TLR4, increased following oral administration of glucan. Oral glucan increased systemic levels of interleukin (IL)-12 (151 Ϯ 15%) in mice. Oral glucan administration also increased survival in mice challenged with Staphylococcus aureus or Candida albicans. These data demonstrate that orally administered water-soluble glucans translocate from the gastrointestinal (GI) tract into the systemic circulation. The glucans are bound by GI epithelial and GALT cells, and they modulate the expression of pattern recognition receptors in the GALT, increase IL-12 expression, and induce protection against infectious challenge.

We examined the effect of modulating phosphoinositide 3-kinase (PI3K) activity in a murine model of cecal ligation and puncture-induced polymicrobial sepsis. Inhibition of PI3K activity with wortmannin increased serum cytokine levels and decreased survival time in septic mice. We have reported that an immunomodulator, glucan phosphate, induces protection in murine polymicrobial sepsis. We observed that glucan stimulated tissue PI3K activity, which positively correlated with increased survival in septic mice. We investigated the effect of PI3K inhibition on survival in septic mice treated with glucan. Treatment of mice with the PI3K inhibitors, wortmannin and LY294002, completely eliminated the protective effect of glucan, indicating that protection against septic mortality was mediated through PI3K. Inhibition of PI3K resulted in increased serum levels of IL1-β, IL-2, IL-6, IL-10, IL-12, and TNF-α in septic mice. Apoptosis is thought to play a central role in the response to septic injury. We observed that inhibition of PI3K activity in septic mice resulted in increased splenocyte apoptosis and a change in the anatomic distribution of splenocyte apoptosis. We conclude that PI3K is a compensatory mechanism that suppresses proinflammatory and apoptotic processes in response to sepsis and/or inflammatory injury. Thus, PI3K may play a pivotal role in the maintenance of homeostasis and the integrity of the immune response during sepsis. We also observed that glucan phosphate decreased septic morbidity and mortality through a PI3K-dependent mechanism. This suggests that stimulation of the PI3K pathway may be an effective approach for preventing or treating sepsis and/or septic shock.

This study investigated physiological and performance changes of a national level 69kg female weightlifter following three competition phases over a 28-week training period. The athlete first trained for a regional championship (weeks 1-12), followed by a local competition (weeks 13-23) and the national championship (weeks 24-28). Body mass, vastus lateralis cross-sectional area, and unloaded and loaded squat jump performance were assessed weekly during each 4-week competition phase. Serum biomarkers, and dynamic mid-thigh pulls were assessed prior to and after each competition phase. Weightlifting performance goals were met for the regional championship (total=200kg) and the local competition (total=193kg), but not the national championship (total=196kg). She lost more body mass in preparation for nationals (-6.0kg) compared to regionals (-2.5kg) and the local competition (+2.2kg). Vastus lateralis cross-sectional area very likely decreased following nationals (precision=99%, effect size=2.08). Her testosterone:cortisol ratio likely increased (88%, 2.64), while interleukin-6 (79%, 2.47), and tumor necrosis factor-alpha (81%, 3.59) likely decreased following nationals. Serum myostatin (99%, 1.95) and decorin (99%, 1.96) very likely decreased following the local competition. Unloaded squat jump height likely increased the week of regionals (89%, 0.95) and the local competition (99%, 1.83), whereas unloaded and loaded squat jump height possibly (69%, 0.99) and likely (82%, 1.52) decreased the week of nationals. Dynamic mid-thigh pull vertical displacement likely increased following regionals (93%, 0.84), and likely decreased following nationals (94%, 0.87). These findings indicate that biomarkers of stress, inflammation, and hypertrophy are related to changes in training volume-load; however, performance measures are needed to assess competition preparedness. Considering the reductions in muscle cross-sectional area corresponding with the large reductions in body mass and underperformance at the national championship, sport scientists and coaches should instruct weightlifters to not attempt large losses in body mass (e.g. >3 kg) close to competition (e.g. <1 week).

Four experiments were designed to examine the contribution of the oocyte or the follicular, oviductal, or early uterine environments to low fertility associated with the first ovulation postpartum. At 17-25 days postpartum in experiments 1, 2, and 3, suckled beef cows were assigned at random to receive 6 mg norgestomet, via ear-implant, for 9 days (NOR) or to serve as controls (CON). Calves were weaned from all cows 7 days after assignment to treatment in order to induce estrus, an LH surge, ovulation, and subsequent formation of CL. As cows were detected to be in estrus, they were bred first by natural service and 12 h later by artificial insemination. In experiment 1, on Day 3 after estrus, the oviduct ipsilateral to the side of ovulation was removed and flushed for recovery of an embryo or oocyte. Rates of recovery (86%), fertilization (68%), and development of fertilized oocytes to the 4- to 8-cell stage (100%) did not differ between CON and NOR cows. In experiment 2, uteri were flushed nonsurgically on Day 6 after estrus. Rates of recovery of embryos from the uterus were similar between CON (86%) and NOR (71%) cows. In experiment 3, one half of the cows in each group (CON and NOR) were fed melengestrol acetate (MGA) beginning on Day 4 after estrus and continuing until Day 35. The remaining cows in each group served as controls. Treatment with NOR increased (p < 0.05) the proportion of cows that maintained pregnancy until Day 35 (9/22) as compared to controls (0/18).(ABSTRACT TRUNCATED AT 250 WORDS)

Eicosanoid production by macrophages is an early response to microbial infection that promotes acute inflammation. The intracellular pathogen Listeria monocytogenes stimulates arachidonic acid release and eicosanoid production from resident mouse peritoneal macrophages through activation of group IVA cytosolic phospholipase A 2 (cPLA 2 ␣).

Sepsis is a frequent complication in critical illness. The mechanisms that are involved in initiation and propagation of the disease are not well understood. Scavenger receptor A (SRA) is a membrane receptor that binds multiple polyanions such as oxidized LDL and endotoxin. Recent studies suggest that SRA acts as a pattern recognition receptor in the innate immune response. The goal of the present study was to determine the role of SRA in polymicrobial sepsis. SRA deficient (SRA−/−) and C57BL/6JB/6J (WT) male mice were subjected to cecal ligation and puncture (CLP) to induce polymicrobial sepsis. NFκB activity, myeloperoxidase activity, and co-association of SRA with toll like receptor (TLR) 4 and TLR2 was analyzed in the lungs. Spleens were analyzed for apoptosis. Serum cytokines and chemokines were assayed. Blood and peritoneal fluid were cultured for aerobic and anaerobic bacterial burdens. Long term survival was significantly increased in SRA−/− septic mice (53.6% vs. 3.6%, p<0.05) when compared to WT mice. NFκB activity was 45.5% lower in the lungs of SRA−/− septic mice versus WT septic mice (p<0.05). Serum levels of interleukin (IL)-5, IL-6, IL-10 and monocyte chemoattractant protein −1 were significantly lower in septic SRA−/− mice when compared to septic WT mice (p<0.05). We found that SRA immuno-precipitated with TLR4, but not TLR2, in the lungs of WT septic mice. We also found that septic SRA−/− mice had lower bacterial burdens than WT septic mice. SRA deficiency had no effect on pulmonary neutrophil infiltration or splenocyte apoptosis during sepsis. We conclude that SRA plays a pivotal, and previously unknown, role in mediating the pathophysiology of sepsis/septic shock in a murine model of polymicrobial sepsis. Mechanistically, SRA interacts with TLR4 to enhance the development of the pro-inflammatory phenotype and mediate the morbidity and mortality of sepsis/septic shock.

Summary Heterotrimeric Gi proteins play a role in signalling activated by lipopolysaccharide (LPS), Staphylococcus aureus (SA) and group B streptococci (GBS), leading to production of inflammatory mediators. We hypothesized that genetic deletion of Gi proteins would alter cytokine and chemokine production induced by LPS, SA and GBS stimulation. LPS‐induced, heat‐killed SA‐induced and heat‐killed GBS‐induced cytokine and chemokine production in peritoneal macrophages from wild‐type (WT), Gαi2–/– or Gαi1/3–/– mice were investigated. LPS induced production of tumour necrosis factor‐α (TNF‐α), interleukin‐6 (IL‐6), IL‐10 and interferon‐γ‐inducible protein‐10 (IP‐10); SA induced TNF‐α, and IL‐1β production; and GBS induced TNF‐α, IL‐6, IL‐1β, macrophage inflammatory protein‐1α (MIP‐1α) and keratinocyte chemoattract (KC) production were all decreased (P < 0·05) in Gαi2–/– or Gαi1/3–/– mice compared with WT mice. In contrast to the role of Gi proteins as a positive regulator of mediators, LPS‐induced production of MIP‐1α and granulocyte–macrophage colony‐stimulating factor (GM‐CSF) were increased in macrophages from Gαi1/3–/– mice, and SA‐induced MIP‐1α production was increased in both groups of Gαi protein‐depleted mice. LPS‐induced production of KC and IL‐1β, SA‐induced production of GM‐CSF, KC and IP‐10, and GBS‐induced production of IL‐10, GM‐CSF and IP‐10 were unchanged in macrophages from Gαi2–/– or Gαi1/3–/– mice compared with WT mice. These data suggest that Gi2 and Gi1/3 proteins are both involved and differentially regulate murine inflammatory cytokine and chemokine production in response to both LPS and Gram‐positive microbial stimuli.

To determine if known androgenic hormone precursors for testosterone in the androgen pathway would be readily transformed to testosterone, eight male subjects [mean age 23.8 (SEM 3) years, bodymass 83.1 (SEM 8.7) kg, height 175.6 (SEM 8.5) cm] underwent a randomized, double-blind, cross-over, placebo-controlled oral treatment with 200 mg of 4-androstene-3,17-dione (delta 4), 4-androstene-3 beta,17 beta-diol (delta 4 Diol), and placebo (PL). The periods of study were separated by 7 days of washout. Blood was drawn at baseline and subsequently every 30 min for 90 min after treatment. Analysis revealed mean area-under-the-curve (AUC) serum delta 4 concentrations to be higher during delta 4 treatment [2177 (SEM 100) nmol.l-1] than delta 4Diol [900 (SEM 96) nmol.l-1] or PL [484 (SEM 82) nmol.l-1; P < 0.0001]. The delta 4 treatment also revealed a significant effect on total testosterone with a mean AUC [1632.5 (SEM 121) nmol.l-1] that was greater than PL [1418.5 (SEM 131) nmol.l-1; P < 0.05] but not significantly different from those observed after delta 4Diol treatment [1602.9 (SEM 119) nmol.l-1; P = 0.77]. Free testosterone concentrations followed a similar pattern where mean AUC for the delta 4 treatment [6114.0 (SEM 600) pmol.l-1] was greater than after PL [4974.6 (SEM 565) pmol.l-1; P < 0.06] but not significantly different from those observed after delta 4Diol [5632.0 (SEM 389) pmol.l-1; P = 0.48]. The appearance and apparent conversion to total and free testosterone over 90 min was stronger for the delta 4 treatment (r = 0.91, P < 0.045) than for delta 4Diol treatment (r = 0.69, NS) and negatively correlated for PL (r = -0.90, P < 0.02). These results would suggest that delta 4, and perhaps delta 4Diol, taken by month are capable of producing in vivo increases in testosterone concentrations in apparently healthy young men as has already been observed in women after treatment with delta 4.