Pharmacokinetic and Pharmacodynamic Analyses To Determine the Optimal Fixed Dosing Regimen of Iclaprim for Treatment of Patients with Serious Infections Caused by Gram-Positive Pathogens.

Iclaprim is a bacterial dihydrofolate reductase inhibitor that is currently being evaluated in two phase 3 trials for the treatment of patients with acute bacterial skin and skin structure infections (ABSSSI). Prior animal infection model studies suggest that the pharmacokinetic/pharmacodynamic (PK/PD) drivers for efficacy are area under the concentration-time curve from 0 to 24 h at steady state (AUC0-24ss), AUC/MIC, and time above the MIC during the dosing interval (T > MIC), while QTc prolongation was associated with the maximal concentration at steady state (Cmaxss) in a thorough QTc phase 1 study. Using PK data collected from 470 patients from the previously conducted phase 3 complicated skin and skin structure infection (cSSSI) trials, population PK modeling and Monte Carlo simulation (MCS) were used to identify a fixed iclaprim dosage regimen for the ongoing phase 3 ABSSSI studies that maximizes AUC0-24ss, AUC/MIC, and T > MIC while minimizing the probability of a Cmaxss of ≥800 ng/ml relative to the values for the previously employed cSSSI regimen of 0.8 mg/kg of body weight infused intravenously over 0.5 h every 12 h. The MCS analyses indicated that administration of 80 mg as a 2-h infusion every 12 h provides 28%, 28%, and 32% increases in AUC0-24ss, AUC/MIC, and T > MIC, respectively, compared to values for the 0.8-mg/kg cSSSI regimen, while decreasing the probability of a Cmaxss of ≥800 ng/ml, by 9%. Based on PK/PD analyses, 80 mg iclaprim administered over 2 h every 12 h was selected as the dosing scheme for subsequent phase 3 clinical trials.

Concentrated fish oil (Lovaza(R)) extends lifespan and attenuates kidney disease in lupus-prone short-lived (NZBxNZW)F1 mice.

A growing number of reports indicate that anti-inflammatory actions of fish oil (FO) are beneficial against systemic lupus erythematosus (SLE). However, the majority of pre-clinical studies were performed using 5-20% FO, which is higher than the clinically relevant dose for lupus patients. The present study was performed in order to determine the effective low dose of FDA-approved concentrated FO (Lovaza®) compared to the commonly used FO-18/12 (18-Eicosapentaenoic acid [EPA]/12-Docosahexaenoic acid [DHA]). We examined the dose-dependent response of Lovaza® (1% and 4%) on an SLE mouse strain (NZBxNZW)F1 and compared the same with 1% and 4% placebo, as well as 4% FO-18/12, maintaining standard chow as the control. Results show for the first time that 1% Lovaza® extends maximal lifespan (517 d) and 4% Lovaza® significantly extends both the median (502 d) and maximal (600 d) life span of (NZBxNZW)F1 mice. In contrast, FO-18/12 extends only median lifespan (410 d) compared to standard chow diet (301 d). Additionally, 4% Lovaza® significantly decreased anti-dsDNA antibodies, reduced glomerulonephritis and attenuated lipopolysaccharide-induced pro-inflammatory cytokines (IL-1ß, IL-6, TNF-α) in splenocytes compared to placebo. 4% Lovaza® was also shown to reduce the expression of inflammatory cytokines, including IL-1ß, IL-6 and TNF-α, while increasing renal anti-oxidant enzymes in comparison to placebo. Notably, NFκB activation and p65 nuclear translocation were lowered by 4% Lovaza® compared to placebo. These data indicate that 1% Lovaza® is beneficial, but 4% Lovaza® is more effective in suppressing glomerulonephritis and extending life span of SLE-prone short-lived mice, possibly via reducing inflammation signaling and modulating oxidative stress.

Dietary coral calcium and zeolite protects bone in a mouse model for postmenopausal bone loss.

In patients diagnosed with osteoporosis, calcium is lost from bones making them weaker and easily susceptible to fractures. Supplementation of calcium is highly recommended for such conditions. However, the source of calcium plays an important role in the amount of calcium that is assimilated into bone. We hypothesize that naturally occurring coral calcium and zeolite may prevent ovariectomy-induced bone loss. We have measured bone loss in ovariectomized mice supplemented with coral calcium and Zeolite. Female C57BL/6 mice were either sham-operated or ovariectomized and fed diets containing coral calcium or zeolite for 6 months. Serum was analyzed for bone biochemical markers and cytokines. Bones were analyzed using dual x-ray absorbtiometry, peripheral quantitative computed tomography, and micro-computed tomography densitometry. In the distal femoral metaphysis, total bone and cortical bone mass was restored and the endocortical surface was significantly decreased in coral calcium and zeolite fed ovariectomized (OVX) mice. Trabecular number and the ratio of bone volume to total volume was higher in OVX mice after coral calcium and zeolite feeding, while trabecular separation decreased in the different treatment OVX groups. Coral calcium protected bone to a lesser extent in the proximal tibia and lumbar vertebrae. Overall, coral calcium and zeolite may protect postmenopausal bone loss.

Fish oil concentrate delays sensitivity to thermal nociception in mice.

Fish oil has been used to alleviate pain associated with inflammatory conditions such as rheumatoid arthritis. The anti-inflammatory property of fish oil is attributed to the n-3 fatty acids docosahexaenoic acid and eicosapentaenoic acid. Contrarily, vegetable oils such as safflower oil are rich in n-6 fatty acids which are considered to be mediators of inflammation. This study investigates the effect of n-3 and n-6 fatty acids rich oils as dietary supplements on the thermally induced pain sensitivity in healthy mice. C57Bl/6J mice were fed diet containing regular fish oil, concentrated fish oil formulation (CFO) and safflower oil (SO) for 6 months. Pain sensitivity was measured by Plantar test and was correlated to the expression of acid sensing ion channels (ASICs), transient receptor potential vanilloid 1 (TRPV1) and c-fos in dorsal root ganglion cells. Significant delay in sensitivity to thermal nociception was observed in mice fed CFO compared to mice fed SO (p<0.05). A significant diminution in expression of ion channels such as ASIC1a (64%), ASIC13 (37%) and TRPV1 (56%) coupled with reduced expression of c-fos, a marker of neuronal activation, was observed in the dorsal root ganglion cells of mice fed CFO compared to that fed SO. In conclusion, we describe here the potential of fish oil supplement in reducing sensitivity to thermal nociception in normal mice.

Fish oil decreases inflammation and reduces cardiac remodeling in rosiglitazone treated aging mice.

Clinical studies suggest that rosiglitazone (RSG) treatment may increase the incidence of heart failure in diabetic patients. In this study, we examined whether a high corn oil diet with RSG treatment in insulin resistant aging mice exerted metabolic and pro-inflammatory effects that stimulate cardiac dysfunction. We also evaluated whether fish oil attenuated these effects. Female C57BL/6J mice (13 months old) were divided into 5 groups: (1) lean control (LC), (2) corn oil, (3) fish oil, (4) corn oil+RSG and (5) fish oil+RSG. Mice fed a corn oil enriched diet and RSG developed hypertrophy of the left ventricle (LV) and decreased fractional shortening, despite a significant increase in total body lean mass. In contrast, LV hypertrophy was prevented in RSG treated mice fed a fish oil enriched diet. Importantly, hyperglycemia was controlled in both RSG groups. Further, fish oil+RSG decreased LV expression of atrial and brain natriuretic peptides, fibronectin and the pro-inflammatory cytokines interleukin-6 and tumor necrosis factor-α, concomitant with increased interleukin-10 and adiponectin levels compared to the corn oil+RSG group. Fish oil+RSG treatment suppressed inflammation, increased serum adiponectin, and improved fractional shortening, attenuating the cardiac remodeling seen in the corn oil+RSG diet fed C57BL/6J insulin resistant aging mice. Our results suggest that RSG treatment has context-dependent effects on cardiac remodeling and serves a negative cardiac role when given with a corn oil enriched diet.

Combination of conjugated linoleic acid with fish oil prevents age-associated bone marrow adiposity in C57Bl/6J mice.

The inverse relationship between fat in bone marrow and bone mass in the skeleton of aging subjects is well known. However, there is no precise therapy for the treatment of bone marrow adiposity. We investigated the ability of conjugated linoleic acid (CLA) and fish oil (FO), alone or in combination, to modulate bone loss using 12 months old C57Bl/6J mice fed 10% corn oil diet as control or supplemented with 0.5% CLA or 5% FO or 0.5% CLA+5% FO for 6 months. We found, CLA-fed mice exhibited reduced body weight, body fat mass (BFM) and enhanced hind leg lean mass (HLLM) and bone mineral density (BMD) in different regions measured by dual energy x-ray absorptiometry (DXA); however, associated with fatty liver and increased insulin resistance; whereas, FO fed mice exhibited enhanced BMD, improved insulin sensitivity, with no changes in BFM and HLLM. Interestingly, CLA+FO fed mice exhibited reduced body weight, BFM, peroxisome proliferator-activated receptor gamma and cathepsin K expression in bone marrow with enhanced BMD and HLLM. Moreover, CLA+FO supplementation reduced liver hypertrophy and improved insulin sensitivity with remarkable attenuation of bone marrow adiposity, inflammation and oxidative stress in aging mice. Therefore, CLA with FO combination might be a novel dietary supplement to reduce fat mass and improve BMD.

Obesity-mediated inflammatory microenvironment stimulates osteoclastogenesis and bone loss in mice.

Clinical evidence indicates that fat is inversely proportional to bone mass in elderly obese women. However, it remains unclear whether obesity accelerates bone loss. In this report we present evidence that increased visceral fat leads to inflammation and subsequent bone loss in 12-month-old C57BL/6J mice that were fed 10% corn oil (CO)-based diet and a control lab chow (LC) for 6 months. As expected from our previous work, CO-fed mice demonstrated increased visceral fat and enhanced total body fat mass compared to LC. The adipocyte-specific PPARγ and bone marrow (BM) adiposity were increased in CO-fed mice. In correlation with those modifications, inflammatory cytokines (IL-1ß, IL-6, TNF-α) were significantly elevated in CO-fed mice compared to LC-fed mice. This inflammatory BM microenvironment resulted in increased superoxide production in osteoclasts and undifferentiated BM cells. In CO-fed mice, the increased number of osteoclasts per trabecular bone length and the increased osteoclastogenesis assessed ex-vivo suggest that CO diet induces bone resorption. Additionally, the up-regulation of osteoclast-specific cathepsin k and RANKL expression and down-regulation of osteoblast-specific RUNX2/Cbfa1 supports this bone resorption in CO-fed mice. Also, CO-fed mice exhibited lower trabecular bone volume in the distal femoral metaphysis and had reduced OPG expression. Collectively, our results suggest that increased bone resorption in mice fed a CO-enriched diet is possibly due to increased inflammation mediated by the accumulation of adipocytes in the BM microenvironment. This inflammation may consequently increase osteoclastogenesis, while reducing osteoblast development in CO-fed mice.

High fat diet-induced animal model of age-associated obesity and osteoporosis.

Osteoporosis and obesity remain a major public health concern through its associated fragility and fractures. Several animal models for the study of osteoporotic bone loss, such as ovariectomy (OVX) and denervation, require unique surgical skills and expensive set up. The challenging aspect of these age-associated diseases is that no single animal model exactly mimics the progression of these human-specific chronic conditions. Accordingly, to develop a simple and novel model of post menopausal bone loss with obesity, we fed either a high fat diet containing 10% corn oil (CO) or standard rodent lab chow (LC) to 12-month-old female C57Bl/6J mice for 6 months. As a result, CO fed mice exhibited increased body weight, total body fat mass, abdominal fat mass and reduced bone mineral density (BMD) in different skeletal sites measured by dual energy X-ray absorptiometry. We also observed that decreased BMD with age in CO fed obese mice was accompanied by increased bone marrow adiposity, up-regulation of peroxisome proliferator-activated receptor γ, cathepsin k and increased proinflammatory cytokines (interleukin 6 and tumor necrosis factor α) in bone marrow and splenocytes, when compared to that of LC fed mice. Therefore, this appears to be a simple, novel and convenient age-associated model of post menopausal bone loss, in conjunction with obesity, which can be used in pre-clinical drug discovery to screen new therapeutic drugs or dietary interventions for the treatment of obesity and osteoporosis in the human population.