Effects of phosphodiesterase 4 inhibition on bleomycin-induced pulmonary fibrosis in mice

<p>Abstract</p> <p>Background</p> <p>Pulmonary fibrosis (PF) is a group of devastating and largely irreversible diseases. Phosphodiesterase (PDE) 4 is involved in the processes of remodeling and inflammation, which play key role in tissue fibrosis. The aim of the study was, therefore, to investigate the effect of PDE4 inhibition in experimental model of PF.</p> <p>Methods</p> <p>PF was induced in C57BL/6N mice by instillation of bleomycin. Pharmacological inhibition of PDE4 was achieved by using cilomilast, a selective PDE4 inhibitor. Changes in either lung inflammation or remodeling were evaluated at different stages of experimental PF. Lung inflammation was assessed by bronchoalveolar lavage fluid (BALF) differential cell count and reverse transcription quantitative polymerase chain reaction (RT-qPCR) for inflammatory cytokines. Changes in tissue remodeling were evaluated by pulmonary compliance measurement, quantified pathological examination, measurement of collagen deposition and RT-qPCR for late remodeling markers. Survival in all groups was analyzed as well.</p> <p>Results</p> <p>PDE4 inhibition significantly reduced the total number of alveolar inflammatory cells in BALF of mice with bleomycin-induced PF at early fibrosis stage (days 4 and 7). Number of macrophages and lymphocytes, but not neutrophils, was significantly reduced as well. Treatment decreased lung tumor necrosis factor (TNF)-α mRNA level and increased mRNA level of interleukin (IL)-6 but did not influence IL-1β. At later stage (days 14 and 24) cilomilast improved lung function, which was shown by increase in lung compliance. It also lowered fibrosis degree, as was shown by quantified pathological examination of Hematoxilin-Eosin stained lung sections. Cilomilast had no significant effect on the expression of late remodeling markers such as transforming growth factor (TGF)-β1 and collagen type Ia1 (COL(I)α1). However, it tended to restore the level of lung collagen, assessed by SIRCOL assay and Masson's trichrome staining, and to improve the overall survival.</p> <p>Conclusions</p> <p>Selective PDE4 inhibition suppresses early inflammatory stage and attenuates the late stage of experimental pulmonary fibrosis.</p

An Exploratory Descriptive Study of Antimicrobial Resistance Patterns of Staphylococcus Spp. Isolated from Horses Presented at a Veterinary Teaching Hospital

Background Antimicrobial resistant Staphylococcus are becoming increasingly important in horses because of the zoonotic nature of the pathogens and the associated risks to caregivers and owners. Knowledge of the burden and their antimicrobial resistance patterns are important to inform control strategies. This study is an exploratory descriptive investigation of the burden and antimicrobial drug resistance patterns of Staphylococcus isolates from horses presented at a veterinary teaching hospital in South Africa. Methods Retrospective laboratory clinical records of 1027 horses presented at the University of Pretoria veterinary teaching hospital between 2007 and 2012 were included in the study. Crude and factor-specific percentages of Staphylococcus positive samples, antimicrobial resistant (AMR) and multidrug resistant (MDR) isolates were computed and compared across Staphylococcus spp., geographic locations, seasons, years, breed and sex using Chi-square and Fisher’s exact tests. Results Of the 1027 processed clinical samples, 12.0% were Staphylococcus positive. The majority of the isolates were S. aureus (41.5%) followed by S. pseudintermedius(14.6%). Fifty-two percent of the Staphylococcus positive isolates were AMR while 28.5% were MDR. Significant (p \u3c 0.05) differences in the percentage of samples with isolates that were AMR or MDR was observed across seasons, horse breeds and Staphylococcus spp. Summer season had the highest (64.3%) and autumn the lowest (29.6%) percentages of AMR isolates. Highest percentage of AMR samples were observed among the Boerperds (85.7%) followed by the American saddler (75%) and the European warm blood (73.9%). Significantly (p \u3c 0.001) more S. aureus isolates (72.5%) were AMR than S. pseudintermedius isolates (38.9%). Similarly, significantly (p \u3c 0.001) more S. aureus (52.9%) exhibited MDR than S. pseudintermedius (16.7%). The highest levels of AMR were towards β-lactams (84.5%) followed by trimethoprim/sulfamethoxazole (folate pathway inhibitors) (60.9%) while the lowest levels of resistance were towards amikacin (14.%). Conclusions This exploratory study provides useful information to guide future studies that will be critical for guiding treatment decisions and control efforts. There is a need to implement appropriate infection control, and judicious use of antimicrobials to arrest development of antimicrobial resistance. A better understanding of the status of the problem is a first step towards that goal

Identification of Intracellular and Plasma Membrane Calcium Channel Homologues in Pathogenic Parasites

Ca2+ channels regulate many crucial processes within cells and their abnormal activity can be damaging to cell survival, suggesting that they might represent attractive therapeutic targets in pathogenic organisms. Parasitic diseases such as malaria, leishmaniasis, trypanosomiasis and schistosomiasis are responsible for millions of deaths each year worldwide. The genomes of many pathogenic parasites have recently been sequenced, opening the way for rational design of targeted therapies. We analyzed genomes of pathogenic protozoan parasites as well as the genome of Schistosoma mansoni, and show the existence within them of genes encoding homologues of mammalian intracellular Ca2+ release channels: inositol 1,4,5-trisphosphate receptors (IP3Rs), ryanodine receptors (RyRs), two-pore Ca2+ channels (TPCs) and intracellular transient receptor potential (Trp) channels. The genomes of Trypanosoma, Leishmania and S. mansoni parasites encode IP3R/RyR and Trp channel homologues, and that of S. mansoni additionally encodes a TPC homologue. In contrast, apicomplexan parasites lack genes encoding IP3R/RyR homologues and possess only genes encoding TPC and Trp channel homologues (Toxoplasma gondii) or Trp channel homologues alone. The genomes of parasites also encode homologues of mammalian Ca2+ influx channels, including voltage-gated Ca2+ channels and plasma membrane Trp channels. The genome of S. mansoni also encodes Orai Ca2+ channel and STIM Ca2+ sensor homologues, suggesting that store-operated Ca2+ entry may occur in this parasite. Many anti-parasitic agents alter parasite Ca2+ homeostasis and some are known modulators of mammalian Ca2+ channels, suggesting that parasite Ca2+ channel homologues might be the targets of some current anti-parasitic drugs. Differences between human and parasite Ca2+ channels suggest that pathogen-specific targeting of these channels may be an attractive therapeutic prospect

Canagliflozin and Renal Outcomes in Type 2 Diabetes and Nephropathy

BACKGROUND Type 2 diabetes mellitus is the leading cause of kidney failure worldwide, but few effective long-term treatments are available. In cardiovascular trials of inhibitors of sodium–glucose cotransporter 2 (SGLT2), exploratory results have suggested that such drugs may improve renal outcomes in patients with type 2 diabetes. METHODS In this double-blind, randomized trial, we assigned patients with type 2 diabetes and albuminuric chronic kidney disease to receive canagliflozin, an oral SGLT2 inhibitor, at a dose of 100 mg daily or placebo. All the patients had an estimated glomerular filtration rate (GFR) of 30 to 300 to 5000) and were treated with renin–angiotensin system blockade. The primary outcome was a composite of end-stage kidney disease (dialysis, transplantation, or a sustained estimated GFR of <15 ml per minute per 1.73 m 2), a doubling of the serum creatinine level, or death from renal or cardiovascular causes. Prespecified secondary outcomes were tested hierarchically. RESULTS The trial was stopped early after a planned interim analysis on the recommendation of the data and safety monitoring committee. At that time, 4401 patients had undergone randomization, with a median follow-up of 2.62 years. The relative risk of the primary outcome was 30% lower in the canagliflozin group than in the placebo group, with event rates of 43.2 and 61.2 per 1000 patient-years, respectively (hazard ratio, 0.70; 95% confidence interval [CI], 0.59 to 0.82; P=0.00001). The relative risk of the renal-specific composite of end-stage kidney disease, a doubling of the creatinine level, or death from renal causes was lower by 34% (hazard ratio, 0.66; 95% CI, 0.53 to 0.81; P<0.001), and the relative risk of end-stage kidney disease was lower by 32% (hazard ratio, 0.68; 95% CI, 0.54 to 0.86; P=0.002). The canagliflozin group also had a lower risk of cardiovascular death, myocardial infarction, or stroke (hazard ratio, 0.80; 95% CI, 0.67 to 0.95; P=0.01) and hospitalization for heart failure (hazard ratio, 0.61; 95% CI, 0.47 to 0.80; P<0.001). There were no significant differences in rates of amputation or fracture. CONCLUSIONS In patients with type 2 diabetes and kidney disease, the risk of kidney failure and cardiovascular events was lower in the canagliflozin group than in the placebo group at a median follow-up of 2.62 years