Tissue disposition of azithromycin after intravenous and intramuscular administration to rabbits

Inherent Fluorescence Demonstrates Immunotropic Properties for Novel Janus Kinase 3 Inhibitors

There is a general question in small molecule pharmacology about how apparent compound concentrations in blood, plasma, and organs actually relate to actual amounts at the target site of a compound. In this study, we used inherently fluorescent JAK3 ligands and their macrolide conjugates to investigate the relationship between physical properties, apparent bulk concentration, and organ and subcellular distribution. In vitro uptake into immune cells suggested that much of the substance was associated with granules or organelles. Samples from murine pharmacokinetic studies were analyzed by both conventional mass spectrometry and cryofluorescence microscopy methods to show the distribution of a compound within organs and cells without artifacts of fixation. These observations confirm the uptake of granules observed in vitro. Data from macrolides carrying either a coumarin fluorophore or a JAK3 inhibitor were similar, suggesting that the distribution is directed by the properties of the larger macrolide. These data show a propensity for azalide macrolides to concentrate in the lung and gut epithelia and suggest that the plasma- or whole-blood-derived estimates of drug levels almost certainly underestimate concentrations of macrolides in the mucous membranes. Thus, their apparent efficacy at sub-bacteriostatic doses may reflect their higher levels in barrier layers.

Selective Inhibitors of Janus Kinase 3 Modify Responses to Lipopolysaccharides by Increasing the Interleukin-10-to-Tumor Necrosis Factor α Ratio

Janus kinase (JAK) inhibitors act at low doses (e.g., tofacitinib, 0.2-0.4 μmol/kg bid) in clinical use, suggesting an efficient underlying mode of action. We hypothesized that their effectiveness is due to their ability to raise the ratio of IL-10 to TNFα. Unlike other JAK isoforms, JAK3 is expressed mainly in hematopoietic cells and is essential for immune function. We used JAK3 selective inhibitors with preferential distribution to immune cells. Inhibition of JAK3 in human leukocytes reduced TNFα and IL-6 but maintained levels of IL-10, while pan-JAK inhibitors increased TNFα, IL-6, and IL-10. JAK1 is required for IL-10 receptor signaling, which suggests that, at exposure above the IC50 (55 nM for tofacitinib on JAK1), there is less feedback control of TNFα levels. This leads to self-limiting effects of JAK1 inhibitors and could place an upper limit on appropriate doses. In vivo, treating mice with JAK3 inhibitors before LPS administration decreased plasma TNFα and increased IL-10 above vehicle levels, suggesting that JAK3 inhibition may limit TNFα release by increasing IL-10 while leaving the IL-10 receptor functional. This mechanism should have general utility in controlling autoimmune diseases and can be conveniently observed by measuring the ratio of IL-10 to TNFα. In summary, our targeted, "leukotropic" inhibitors more effectively increased IL-10/TNFα ratios than unselective control compounds and could, therefore, be ideal for autoimmune therapy.

Sundararajan E, Asadi S, Nilashi M, Ab Aziz MJ, Saravanan MS, Abdelhaq M, Alsaqour R. A Hybrid MCDM Approach Based on Fuzzy-Logic and DEMATEL to Evaluate Adult Obesity

Obesity and its complications is one of the main issues in today's world and is increasing rapidly. A wide range of non-contagious diseases, for instance, diabetes type 2, cardiovascular, high blood pressure and stroke, numerous types of cancer, and mental health issues are formed following obesity. According to the WHO, Malaysia is the sixth Asian country with an adult population suffering from obesity. Therefore, identifying risk factors associated with obesity among Malaysian adults is necessary. For this purpose, this study strives to investigate and assess the risk factors related to obesity and overweight in this country. A quantitative approach was employed by surveying 26 healthcare professionals by questionnaire. Collected data were analyzed with the DEMATEL and Fuzzy Rule-Based methods. We found that lack of physical activity, insufficient sleep, unhealthy diet, genetics, and perceived stress were the most significant risk factors for obesity.

Socio-economic inequalities in the chronic diseases management among Chinese adults aged 45 years and above: a cross sectional study

Backgrounds

Non-communicable diseases (NCDs) have become a priority public health issue. The aim of this study was to examine whether socio-economic inequalities exist in chronic disease management among Chinese adults, and whether the relationship between SES and chronic disease management mediated by social capital.

Methods

We used combined data from China Health and Retirement Longitudinal Study (CHARLS). A total of 19,291 subjects, including 14,905 subjects from 2011 survey, 2036 subjects from 2013, and 2350 subjects from 2015 was included in this study.

Results

Subjects living in urban setting, with higher education attainment and economic status were more likely to have annual health checks, and to be diagnosed for those with hypertension, diabetes and dyslipidemia (all P < 0.05). Social participation could mediate the association between social economic status (SES) and annual health checks, diagnosis of hypertension and dyslipidemia, and health education of hypertension. Health checks could mediate the association between social participation and the diagnosis of hypertension, diabetes and dyslipidemia. The proportions of mediation were 17.5, 23.9 and 8.9%, respectively. There were no mediating effects observed from cognitive social capital variable-perceived helpfulness.

Conclusion

It is necessary to deeply reform our social security system and enhance the social capital construction to promote those low SES people’s physical health.

Distribution and determinants of serum high-sensitivity C-reactive protein in Ethiopian population

BACKGROUND

C-reactive protein (CRP) is an important inflammatory marker associated with different disease conditions, and its concentration differs among ethnicity. This study aimed to determine the distribution and determinants of serum high-sensitive method CRP (hsCRP) that can measure the typically low concentrations, among the Ethiopian population, for which there is no data.

METHODS

A cross-sectional community-based study was conducted in April-June 2015. A total of 5162 individuals aged 15-69 were included. Behavioral, physical, and biochemical measurements were taken using the WHO STEPS non-communicable diseases (NCDs) risk factors assessment tool. Serum hsCRP was determined using Cobas Integra 400 Plus (Roche). Factors associated with hsCRP levels were also considered.

RESULTS

median hsCRP was 0.80 mg/L (Interquartile range, 0.19-2.12) (males: 0.91 mg/L, females: 0.74 mg/L). More than 18% of the study participants had hsCRP greater than 3 mg/L according to the American Heart Association and Centers for Diseases Control and Preventions cut off value. Higher BMI, living in Somali and in Dire Dawa region, and not consuming of fruit or vegetables were independent risk factors for high hsCRP levels.

CONCLUSION

Serum hsCRP levels distribution is comparable to other studies. Until now, no data have been reported in the literature about the Ethiopian population.

Liver-Targeting Class I Selective Histone Deacetylase Inhibitors Potently Suppress Hepatocellular Tumor Growth as Standalone Agents

Dysfunctions in epigenetic regulation play critical roles in tumor development and progression. Histone deacetylases (HDACs) and histone acetyl transferase (HAT) are functionally opposing epigenetic regulators, which control the expression status of tumor suppressor genes. Upregulation of HDAC activities, which results in silencing of tumor suppressor genes and uncontrolled proliferation, predominates in malignant tumors. Inhibition of the deacetylase activity of HDACs is a clinically validated cancer therapy strategy. However, current HDAC inhibitors (HDACi) have elicited limited therapeutic benefit against solid tumors. Here, we disclosed a class of HDACi that are selective for sub-class I HDACs and preferentially accumulate within the normal liver tissue and orthotopically implanted liver tumors. We observed that these compounds possess exquisite on-target effects evidenced by their induction of dose-dependent histone H4 hyperacetylation without perturbation of tubulin acetylation status and G0/G1 cell cycle arrest. Representative compounds 2 and 3a are relatively non-toxic to mice and robustly suppressed tumor growths in an orthotopic model of HCC as standalone agents. Collectively, our results suggest that these compounds may have therapeutic advantage against HCC relative to the current systemic HDACi. This prospect merits further comprehensive preclinical investigations.

Pharmacokinetics of Tildipirosin in Ewes after Intravenous, Intramuscular and Subcutaneous Administration

Simple Summary

Pneumonia is a significant cause of death in sheep flocks. Thus, antibiotics are essential for the treatment of bacterial pneumonia to reduce morbidity and mortality, but few drugs are specifically labeled for clinical use in sheep. Many of the antimicrobial clinical prescriptions that occur in sheep are classified as extra-label use, with dosage, administration frequency, indications, and drug withdrawal times usually being extrapolated from information reported in other species. Thus, the objective of this study was to determine the disposition kinetics of tildipirosin after intravenous, intramuscular, and subcutaneous administration in sheep. Throughout the experiment, all ewes were healthy and no adverse reactions were recorded. The apparent volume of distribution was high, indicating a wide distribution in the body, which can be attributed to a significant fraction of tildipirosin inside the cells, and its expected activity against intracellular bacteria. Following intramuscular administration, tildipirosin was rapidly absorbed even to a greater extent when compared to subcutaneous administration. Most of the adsorbed tildipirosin after intramuscular and subcutaneous administrations were available in the body (>70%). In brief, the excellent tolerability of this formulation and the suitable disposition of tildipirosin in the body makes it an alternative for sheep use, in conditions where the administration of antibiotics is needed to observe desired effects with the benefits of scant manipulation of animals.

Abstract

A single-dose disposition kinetics for tildipirosin was evaluated in clinically healthy ewes (n = 6) after intravenous (IV), intramuscular (IM), and subcutaneous (SC) administration of a commercial formulation. Tildipirosin concentrations were determined by high-performance liquid chromatography with ultraviolet detection. Plasma concentration-time data was calculated by non-compartmental pharmacokinetic methods. The apparent volume of distribution (Vz) of tildipirosin after IV administration was 5.36 ± 0.57 L/kg suggesting a wide distribution in tissues and inside the cells. The elimination half-life (t½λz) was 17.16 ± 2.25, 23.90 ± 6.99 and 43.19 ± 5.17 h after IV, IM and SC administration, respectively. Following IM administration, tildipirosin was rapidly absorbed (tmax = 0.62 ± 0.10 h) even to a greater extent than after SC administration. Time to reach peak concentration (tmax) and peak plasma concentrations (Cmax) differed significantly, but both parameters showed a more significant variability after SC than after IM administration. Bioavailabilities after extravascular administration were high (>70%). Therefore, given general adverse reactions that were not observed in any ewe and favourable pharmacokinetics, tildipirosin could be effective in treating bacterial infections in sheep.

Structural and functional implications of the interaction between macrolide antibiotics and bile acids

Macrolide antibiotics, such as azithromycin and erythromycin, are in widespread use for the treatment of bacterial infections. Macrolides are taken up and excreted mainly by bile. Additionally, they have been implicated in biliary system diseases and to modify the excretion of other drugs through bile. Despite mounting evidence for the interplay between macrolide antibiotics and bile acids, the molecular details of this interaction remain unknown. Herein, we show by NMR measurements that macrolides directly bind to bile acid micelles. The topology of this interaction has been determined by solvent paramagnetic relaxation enhancements (solvent PREs). The macrolides were found to be bound close to the surface of the micelle. Increasing hydrophobicity of both the macrolide and the bile acid strengthen this interaction. Both bile acid and macrolide molecules show similar solvent PREs across their whole structures, indicating that there are no preferred orientations of them in the bile micelle aggregates. The binding to bile aggregates does not impede macrolide antibiotics from targeting bacteria. In fact, the toxicity of azithromycin towards enterotoxic E. coli (ETEC) is even slightly increased in the presence of bile, as was shown by effective concentration (EC50 ) values.

Maternal intravenous administration of azithromycin results in significant fetal uptake in a sheep model of second trimester pregnancy

Treatment of intrauterine infection is likely key to preventing a significant proportion of preterm deliveries before 32 weeks of gestation. Azithromycin (AZ) may be an effective antimicrobial in pregnancy; however, few gestation age-approriate data are available to inform the design of AZ-based treatment regimens in early pregnancy. We aimed to determine whether a single intra-amniotic AZ dose or repeated maternal intravenous (i.v.) AZ doses would safely yield therapeutic levels of AZ in an 80-day-gestation (term is 150 days) ovine fetus. Fifty sheep carrying single pregnancies at 80 days gestation were randomized to receive either: (i) a single intra-amniotic AZ administration or (ii) maternal intravenous AZ administration every 12 h. Amniotic fluid, maternal plasma, and fetal AZ concentrations were determined over a 5-day treatment regimen. Markers of liver injury and amniotic fluid inflammation were measured to assess fetal injury in response to drug exposure. A single intra-amniotic administration yielded significant AZ accumulation in the amniotic fluid and fetal lung. In contrast, repeated maternal intravenous administrations achieved high levels of AZ accumulation in the fetal lung and liver and a statistically significant increase in the fetal plasma drug concentration at 120 h. There was no evidence of fetal injury in response to drug exposure. These data suggest that (i) repeated maternal i.v. AZ dosing yields substantial fetal tissue uptake, although fetal plasma drug levels remain low; (ii) transfer of AZ from the amniotic fluid is less than transplacental transfer; and (iii) exposure to high concentrations of AZ did not elicit overt changes in fetal white blood cell counts, amniotic fluid monocyte chemoattractant protein 1 concentrations, or hepatotoxicity, all consistent with an absence of fetal injury.

Pharmacokinetics of azithromycin in plasma and sinus mucosal tissue following administration of extended-release or immediate-release formulations in adult patients with chronic rhinosinusitis

This study compared the pharmacokinetics of azithromycin (AZI) following administration of extended-release (ER) and immediate-release (IR) formulations in plasma and sinus mucosa in patients with chronic rhinosinusitis. Patients (n=71) were randomised 1:1 to receive a single dose of AZI-ER 2g or up to three doses of AZI-IR 500 mg daily. Paired plasma and sinus tissue samples were taken during endoscopic sinus surgery at 2-168 h (four patients per time point) after the first dose. Samples were measured by a validated liquid chromatography/mass spectrometry assay. Pharmacokinetics were determined using composite concentration-time profiles. Comparison between formulations showed that within the first 24 h, the AZI area under the plasma concentration-time curve (AUC(24)) for ER was 5.2- and 7.0-fold higher than IR in plasma and sinus tissue, respectively. Comparison between matrices showed that the AUC(24) and AUC(168) in sinus tissue were 28.2- and 62.2-fold higher than in plasma for the ER formulation, whilst the AUC(24) in sinus tissue was 21.1-fold higher than in plasma for IR formulation. These results indicated that AZI has good penetration into sinus tissue regardless of formulation; however, dosing of AZI-ER (2 g) increased AZI exposure within the first 24 h compared with the Day 1 dose of 500 mg IR regimen.