Immediate early response protein 2 promotes the migration and invasion of hepatocellular carcinoma cells via regulating the activity of Rho GTPases

Human immediate early response 2 (IER2) has been implicated in tumor cell motility and metastasis; however, the underlying mechanisms in hepatocellular carcinoma (HCC) metastasis remain to be clarified. In this study, we demonstrate that dysregulation of IER2 was shown in HCC clinical samples, and IER2 expression resulted in the promotion of cell migration and invasion in vitro, and HCC tumor growth and pulmonary metastasis in vivo. Moreover, we showed that IER2 expression altered assembly of the actin cytoskeleton rearrangement. Furthermore, MAPK and PI3K/Akt signaling pathways induced by IER2 were confirmed to be probably involved in regulating the activity of Rho GTPases, such as RhoA, Rac1 and Cdc42. Collectively, our results indicated a significant role of IER2 in the HCC cell motility and metastasis through MAPK and PI3K/Akt signaling pathways to regulate the activity of Rho GTPases, thereby modulating actin cytoskeleton rearrangement, unveiling a novel mechanism of cell motility regulation induced by IER2.

Identification of antimicrobial metabolites produced by a potential biocontrol Actinomycete strain A217

AIMS

To extract and identify the metabolites of strain A217 as well as its antifungal spectrum and control effect on various plant pathogens.

METHODS AND RESULTS

Strain A217 was identified as a Streptomyces sp. which was most similar to Streptomyces lienomycini. An antimicrobial spectrum test indicated that strain A217 inhibited several plant pathogenic fungi and strong antibacterial effect such as Phytophthora capsici, Botrytis cinerea, Sclerotinia sclerotiorum, Fusarium oxysporum, Pseudomonas syringae and Xanthomonas campestris. An in vivo tissue test demonstrated that the fermentation broth of strain A217 exerted therapeutic and protective effects of 49·47 and 61·60% respectively, on S. sclerotiorum. Additionally, the fermentation broth of A217 exerted control effects on walnut black spot disease in walnut leaves and branches amounting to 79·33 and 81·52% respectively. In a pot experiment, the fermentation broth exhibited a stronger protective and control effect (68·29%), as well as better bacteriostatic and disease control effects on Phytophthora blight of pepper, compared with Metalaxyl. Compounds possessing antifungal and antibacterial activities were obtained from the fermentation broth of strain A217, using column chromatography and HPLC. Chemical and structural analyses conducted using MS and nuclear magnetic resonance confirmed that these compounds were 1H-pyrrole-2-carboxylic acid and 1H-pyrrole-2-carboxamide. The EC₅₀ values of compound 1H-pyrrole-2-carboxylic acid1 for S. sclerotiorum and P. capsici were 20·13 and 50·36 μg ml^-1 respectively. Compound 1H-pyrrole-2-carboxamide2 showed significant antibacterial activity against different plant pathogenic bacteria. The MIC values of P. syringae, X. campestris and X. campestris pv. jugiandis were 7·5, 30 and 15·0 μg ml^-1 respectively.

CONCLUSIONS

Actinomyces A217 fermentation products have a broad spectrum of bacteriostasis, and have good bacteriostasis activity to many plant pathogenic fungi and bacteria.

SIGNIFICANCE AND IMPACT OF THE STUDY

The present study revealed a new antimicrobial producing strain of Streptomyces and its potential application as a biological control agent for plant diseases.

Molecular mechanism for P38 signaling pathway in autophagy of skin cancer cell line HS-1

OBJECTIVE

Abnormal cell autophagy is correlated with aging, neurodegenerative disease, and skin cancer. The signal transduction pathway of autophagy in skin cancer is still unclear. This study aimed to investigate the role of P38 signal pathway-induced cell autophagy in skin cancer onset and potential clinical application value.

MATERIALS AND METHODS

Skin cancer cell line HS-1 was used as the model for ultraviolet (UV) irritation. Western blot tested autophagy signal molecules P38 activation in skin cancer cell line HS-1. Cells were then treated with P38 pathway agonist and antagonist to test autophagy condition and P38 pathway activation. Correlation analysis was performed to investigate the correlation between P38 pathway and cell autophagy level.

RESULTS

UV irradiation treated skin cancer cell line HS-1 led to cell autophagy and P38 activation. AICAR and SB203580 potentiated and inhibited UV-induced HS-1 cell autophagy, respectively. P38 signal pathway activation condition was positively correlated with autophagy level.

CONCLUSIONS

UV irradiation can induce skin cancer cell autophagy via the P38 signal pathway, indicating that the regulation of the P38 signal pathway activation might be one potential strategy treating skin cancer.

Large-scale state-dependent membrane remodeling by a transporter protein

That channels and transporters can influence the membrane morphology is increasingly recognized. Less appreciated is that the extent and free-energy cost of these deformations likely varies among different functional states of a protein, and thus, that they might contribute significantly to defining its mechanism. We consider the trimeric Na⁺-aspartate symporter Glt_Ph, a homolog of an important class of neurotransmitter transporters, whose mechanism entails one of the most drastic structural changes known. Molecular simulations indicate that when the protomers become inward-facing, they cause deep, long-ranged, and yet mutually-independent membrane deformations. Using a novel simulation methodology, we estimate that the free-energy cost of this membrane perturbation is in the order of 6–7 kcal/mol per protomer. Compensating free-energy contributions within the protein or its environment must thus stabilize this inward-facing conformation for the transporter to function. We discuss these striking results in the context of existing experimental observations for this and other transporters.

[Investigation of treatment and analysis of prognostic risk on enterocutaneous fistula in China: a multicenter prospective study]

Objective: To investigate the diagnosis and treatment for enterocutaneous fistula (ECF) in China, and to explore the prognostic factors of ECF. Methods: A multi-center cross-sectional study was conducted based on the Registration System of Chinese Gastrointestinal Fistula and Intra-Abdominal Infections to collect the clinical data of ECF patients from 54 medical centers in 22 provinces/municipalities from January 1, 2018 to December 31, 2018. The clinical data included patient gender, age, length of hospital stay, intensive care unit (ICU) admission, underlying diseases, primary diseases, direct causes of ECF, location and type of ECF, complications, treatment and outcomes. All medical records were carefully filled in by the attending physicians, and then re-examined by more than two specialists. The diagnosis of ECF was based on the clinical manifestations, laboratory/imaging findings and intraoperative exploration. Results: A total of 1521 patients with ECF were enrolled, including 1099 males and 422 females, with a median age of 55 years. The top three primary diseases of ECF were malignant tumors in 626 cases (41.2%, including 540 gastrointestinal tumors, accounting for 86.3% of malignant tumors), gastrointestinal ulcers and perforations in 202 cases (13.3%), and trauma in 157 cases (10.3%). The direct causes of ECF were mainly surgical operation in 1194 cases (78.5%), followed by trauma in 156 (10.3%), spontaneous fistula due to Crohn's disease in 92 (6.0%), radiation intestinal injury in 41 (2.7%), severe pancreatitis in 20 (1.3%), endoscopic treatment in 13 (0.9%) and 5 cases (0.3%) of unknown reasons. All the patients were divided into three groups: 1350 cases (88.7%) with simple ECF, 150 (9.9%) with multiple ECF, and 21 (1.4%) with combined internal fistula. Among the patients with simple ECF, 438 cases (28.8%) were jejuno-ileal fistula, 313 (20.6%) colon fistula, 170 (11.2%) rectal fistula, 111 (7.3%) duodenal fistula, 76 (5.0%) ileocecal fistula, 65 (4.3%) ileocolic anastomotic fistula, 55 (3.6%) duodenal stump fistula, 36 (2.4%) gastrointestinal anastomotic fistula, 36 (2.4%) esophagogastric/esophagojejunal anastomotic fistula, 29 (1.9%) gastric fistula and 21 (1.4%) cholangiopancreatiointestinal. Among all the simple ECF patients, 991 were tubular fistula and 359 were labial fistula. A total of 1146 patients finished the treatment, of whom 1061 (92.6%) were healed (586 by surgery and 475 self-healing) and 85 (7.4%) died. A total of 1043 patients (91.0%) received nutritional support therapy, and 77 (6.7%) received fistuloclysis. Infectious source control procedures were applied to 1042 patients, including 711 (62.0%) with active lavage and drainage and 331 (28.9%) with passive drainage. Among them, 841 patients (73.4%) underwent minimally invasive procedures of infectious source control (replacement of drainage tube through sinus tract, puncture drainage, etc.), 201 (17.5%) underwent laparotomy drainage, while 104 (9.1%) did not undergo any drainage measures. A total of 610 patients (53.2%) received definitive operation, 24 patients died within postoperative 30-day with mortality of 3.9% (24/610), 69 (11.3%) developed surgical site infection (SSI), and 24 (3.9%) had a relapse of fistula. The highest cure rate was achieved in ileocecal fistula (100%), followed by rectal fistula (96.2%, 128/133) and duodenal stump fistula (95.7%,44/46). The highest mortality was found in combined internal fistula (3/12) and no death in ileocecal fistula. Univariate prognostic analysis showed that primary diseases as Crohn's disease (χ(2)=6.570, P=0.010) and appendicitis/appendiceal abscess (P=0.012), intestinal fistula combining with internal fistula (χ(2)=5.460, P=0.019), multiple ECF (χ(2)=7.135, P=0.008), esophagogastric / esophagojejunal anastomotic fistula (χ(2)=9.501, P=0.002), ECF at ileocecal junction (P=0.012), non-drainage/passive drainage before the diagnosis of intestinal fistula (χ(2)=9.688, P=0.008), non-drainage/passive drainage after the diagnosis of intestinal fistula (χ(2)=9.711, P=0.008), complicating with multiple organ dysfunction syndrome (MODS) (χ(2)=179.699, P<0.001), sepsis (χ(2)=211.851, P<0.001), hemorrhage (χ(2)=85.300, P<0.001), pulmonary infection (χ(2)=60.096, P<0.001), catheter-associated infection (χ(2)=10.617, P=0.001) and malnutrition (χ(2)=21.199, P<0.001) were associated with mortality. Multivariate prognostic analysis cofirmed that sepsis (OR=7.103, 95%CI:3.694-13.657, P<0.001), complicating with MODS (OR=5.018, 95%CI:2.170-11.604, P<0.001), and hemorrhage (OR=4.703, 95%CI: 2.300-9.618, P<0.001) were independent risk factors of the death for ECF patients. Meanwhile, active lavage and drainage after the definite ECF diagnosis was the protective factor (OR=0.223, 95%CI: 0.067-0.745, P=0.015). Conclusions: The overall mortality of ECF is still high. Surgical operation is the most common cause of ECF. Complications e.g. sepsis, MODS, hemorrhage, and catheter-associated infection, are the main causes of death. Active lavage and drainage is important to improve the prognosis of ECF.

Determination of Clopidol Residues in Chicken Tissues by Liquid Chromatography: Collaborative Study

Eighteen laboratories participated in a collaborative study on the determination of clopidol residues in chicken muscle tissues by liquid chromatography. Of these, results from 16 laboratories which rigorously followed the method were subjected to statistical analysis. The method performance was assessed by all participants using 14 samples of chicken muscle fortified at concentrations ranging from 0.1 to 5.0 mg/kg. In addition, 9 participants each reported results for 6 clopidol-incurred samples in chicken muscle. Test portions were extracted with acetonitrile, and the extracts were purified with alumina and anion exchange resin solid-phase extraction cartridges in sequence. Clopidol was separated by reversed-phase liquid chromatography and quantified at 270 nm. Average recoveries ranged from 81.8 to 85.4%, reproducibility relative standard deviation (RSDR) ranged from 11.9 to 22.6%, and repeatability relative standard deviation (RSDr) ranged from 9.9 to 15.1%. For clopidol-incurred samples at concentrations of 0.100–0.687 mg/kg, the mean determination value range was 0.099–0.659 mg/kg; RSDR was 12.6–19.8%, RSDr was 3.1–8.5%; and HORRAT values were 0.7–1.1. The accuracy and precision of the method are in conformity with the requirements specified by AOAC INTERNATIONAL. The method was adopted Official First Action in April 2003.

Heterozygous lys169Glu mutation of glucokinase gene in a Chinese family having glucokinase-maturity-onset diabetes of the young (GCK-MODY)

We report a 24-year-old female with early-onset and persistent mild fasting hyperglycemia due to glucokinase-maturity-onset diabetes of the young (GCK-MODY). A c.505A>G (p. Lys169Glu) missense mutation of the GCK gene was identified. In silico analysis indicated that the mutation affected a conserved amino acid and is disease-causing. This report describes GCK-MODY in a Chinese family and stresses that in managing this condition it is important to avoid unnecessary drug treatment and excessive anxiety about mild hyperglycemia.

[Changes of surgical interventions on necrotizing pancreatitis]

Objective: To investigate the changes of surgical invitations on necrotizing pancreatitis in recent 14 years by reviewing single center data. Methods: One thousand and eighty patients with necrotizing pancreatitis who received surgical invitation were involved in the study.All the patients were treated at Department of Pancreatic Surgery,Union Hospital,Tongji Medical College,Huazhong University of Science and Technology from January 2005 to December 2018. Six hundred and seventy-eight were males and 402 were females. The median (range) age of the study patients was 45 (20-76) years.The etiology of the disease was related to cholelithiasis in 335 cases(31.02%), hyperlipemia in 302 cases(27.96%), alcohol in 226 cases(20.93%), endoscopic retrograde cholangiopancreatography in 28 cases(2.59%), pregnancy in 50 cases(4.63%), idiopathic factors in 72 cases(6.67%) and other causes in 67 cases(6.20%). The patients were divided into two groups according to the time of admission. Group 1 included 1 475 patients that admitted from January 2005 to December 2010, and group 2 included 1 539 patients that admitted from January 2011 to December 2018. The surgical interventions, morbidity and mortality of the two group were compared, and χ(2) test was used for the statistical test. Results: Two hundred and sixty-six among the 1 080 cases were treated with drainage procedures because of the pseudocyst.One hundred and seventy-five drainage procedures were performed between January 2005 and December 2018, which account for 11.87%(175 /1 475) of all patients of necrotizing pancreatitis; 91 drainage procedures were performed between January 2011 and December 2018,which account for 5.91%(91/1 539) of all patients of necrotizing pancreatitis. Eight hundred and fourteen cases received surgical intervention for infection of necrotizing tissues. Of these cases, 410 cases received percutaneous catheter drainage(PCD) of retroperitoneal fluid or residual infection. Debridement of necrotic tissues was performed on 756 cases. Of these cases, 32 cases received minimal invasive retroperitoneal debridement with/without denotes video assistant,4 cases received transluminal endoscopic debridement, 21 cases received laparoscopic debridement, and 709 cases received open laparotic debridement.Three hundred and sixty-five cases were admitted to our institute during January 2005 to December 2010, and the other 391 cases were admitted to our institute from January 2011 to December 2018. Of the first period, all debridement were performed with open laparotic procedures. Of the second period,debridement were performed with open laparotic procedures and minimal invasive procedures. The average times of surgical invasion, morbidity of principal local complications and mortality of the two periods were 1.27 and 1.34,28.22%(103/365) and 29.92%(117/346),and 6.03%(23/365) and 6.91%(27/346), respectively. Conclusions: Minimal invasive procedures can be considered for debridement in patients with necrotizing pancreatitis in some selected conditions.The involvements of minimal invasive procedures in treatment of necrotizing pancreatitis don't decrease the morbidity of principal local complications and mortality in recent years. Rational surgical procedures and appropriate surgical timing are the keys to improve the efficacy of necrotizing pancreatitis.

[Changes of surgical interventions on necrotizing pancreatitis]

Objective: To investigate the changes of surgical invitations on necrotizing pancreatitis in recent 14 years by reviewing single center data. Methods: One thousand and eighty patients with necrotizing pancreatitis who received surgical invitation were involved in the study.All the patients were treated at Department of Pancreatic Surgery,Union Hospital,Tongji Medical College,Huazhong University of Science and Technology from January 2005 to December 2018. Six hundred and seventy-eight were males and 402 were females. The median (range) age of the study patients was 45 (20-76) years.The etiology of the disease was related to cholelithiasis in 335 cases(31.02%), hyperlipemia in 302 cases(27.96%), alcohol in 226 cases(20.93%), endoscopic retrograde cholangiopancreatography in 28 cases(2.59%), pregnancy in 50 cases(4.63%), idiopathic factors in 72 cases(6.67%) and other causes in 67 cases(6.20%). The patients were divided into two groups according to the time of admission. Group 1 included 1 475 patients that admitted from January 2005 to December 2010, and group 2 included 1 539 patients that admitted from January 2011 to December 2018. The surgical interventions, morbidity and mortality of the two group were compared, and χ(2) test was used for the statistical test. Results: Two hundred and sixty-six among the 1 080 cases were treated with drainage procedures because of the pseudocyst.One hundred and seventy-five drainage procedures were performed between January 2005 and December 2018, which account for 11.87%(175 /1 475) of all patients of necrotizing pancreatitis; 91 drainage procedures were performed between January 2011 and December 2018,which account for 5.91%(91/1 539) of all patients of necrotizing pancreatitis. Eight hundred and fourteen cases received surgical intervention for infection of necrotizing tissues. Of these cases, 410 cases received percutaneous catheter drainage(PCD) of retroperitoneal fluid or residual infection. Debridement of necrotic tissues was performed on 756 cases. Of these cases, 32 cases received minimal invasive retroperitoneal debridement with/without denotes video assistant,4 cases received transluminal endoscopic debridement, 21 cases received laparoscopic debridement, and 709 cases received open laparotic debridement.Three hundred and sixty-five cases were admitted to our institute during January 2005 to December 2010, and the other 391 cases were admitted to our institute from January 2011 to December 2018. Of the first period, all debridement were performed with open laparotic procedures. Of the second period,debridement were performed with open laparotic procedures and minimal invasive procedures. The average times of surgical invasion, morbidity of principal local complications and mortality of the two periods were 1.27 and 1.34,28.22%(103/365) and 29.92%(117/346),and 6.03%(23/365) and 6.91%(27/346), respectively. Conclusions: Minimal invasive procedures can be considered for debridement in patients with necrotizing pancreatitis in some selected conditions.The involvements of minimal invasive procedures in treatment of necrotizing pancreatitis don't decrease the morbidity of principal local complications and mortality in recent years. Rational surgical procedures and appropriate surgical timing are the keys to improve the efficacy of necrotizing pancreatitis.

P11.52 Reduced expression of proteolipid protein 2 increases ER-stress-induced apoptosis and autophagy in glioblastoma

BACKGROUND

The PLP2 gene encodes for the Proteolipid protein 2 (PLP2) which is an integral ion channel membrane protein of the endoplasmic reticulum. The protein has been shown to be involved in several human cancers, but the importance of PLP2 in gliomas is poorly understood. In the present study, we therefore investigated the role of PLP2 in human glioma development.

MATERIAL AND METHODS

Immunohistochemistry was carried out for paraffin-embedded glioma samples, and changes in protein level were detected by western blot analysis. Small interfering RNA transfections were used for knockdown of specific genes. Cell viability and proliferation was then assessed by CCK-8 assay and EdU assay. Transmission electron microscopy was used to observe the ultrastructure of the cells and flow cytometry for the evaluation of apoptosis. Finally, U87 and U251 cells were treated with lentiviral transduction to obtain stably PLP2-knockdown cell lines, which were used for an in vivo study.

RESULTS

Data from publicly available datasets (Rembrandt, TCGA and CGGA) showed a correlation between up-regulation of PLP2 levels and increased malignancy. This was confirmed by IHC staining of sections from our own clinical glioma samples. Mechanistically, down-regulation of PLP2 in U87 and U251 glioma cell lines decreased the proliferation and increased apoptosis and autophagy, mediated by ER-stress. In PLP2 knockdown U87 and U251 cells, autophagy inhibition by chloroquine (CQ) augmented apoptotic cell death. Finally, orthotopic U87-shPLP2 and U251-shPLP2 intracranial xenograft models revealed that down-regulating of PLP2 inhibited glioma development in vivo.

CONCLUSION

In conclusion, the results indicate that PLP2 expression is related to glioma progression, and could be a potential target for future treatment strategies.

P11.57 A 3D brain organoid coculture system delineates the invasive cell components in glioblastoma

BACKGROUND

Glioblastoma (GBM) cell infiltration into the surrounding normal brain tissue where the blood brain barrier is intact, represents a major problem for clinical management and therapy. There is a vital need to understand the molecular mechanism that drives tumor cell invasion into the surrounding brain. We have previously developed a 3D coculture model where mature brain organoids are confronted with patient-derived glioblastoma stem-like cells (GSCs). In such a coculture system, single cell invasion into the normal brain tissue can be studied in detail. Here, we first describe in detail, by RNA-seq and proteomics, the differentiation of various neural cell lineages into mature brain organoids as well as their cellular organization. By real-time confocal microscopy and imaging analyses we also determine the speed of tumor cell invasion into the brain. Finally, we used this coculture system to delineate in detail the cellular heterogeneity within the invasive compartment and their gene expression.

MATERIAL AND METHODS

Immunohistochemistry and immunofluorescence were used to determine the expression and distribution of mature neurons, astrocytes, oligodendrocytes, and microglia within the brain organoids. Proteomics and RNA-seq were used to determine brain development ex-vivo. To assess the clonal composition of the GBM-invasive compartment, we used cellular (RGB) barcoding technology. By advanced imaging, we tracked in real time the invasion of barcoded cells into the brain organoids. Finally, we isolated invasive cells and non-invasive cells from our coculture system and used single cell sequencing to analyze their gene expression profiles and molecular phenotypes.

RESULTS

Immunohistochemistry and immunofluorescence showed that brain organoids, after 21 days of differentiation, display a highly cellular and structural organization. RNA-seq and proteomics, performed at different time points of organoid differentiation, revealed that the brain organoids develop into mature brain structures after 21 days as verified by a comparative analysis to normal rat brain development in vivo. Imaging analyses showed that multiple clones within the GBMs have the capacity to invade into the brain tissue with an average speed of ~ 20 μm/h. RNA-sec analysis of the invasive compartment revealed a strong up-regulation of genes and pathways associated with anaerobic respiration (glycolysis).

CONCLUSION

We describe a highly standardized brain organoid coculture system that can be used to delineate GBM invasion ex-vivo. We demonstrate that this platform can be used to unravel the mechanisms that drive GBM invasion into the normal brain.

Effects of zoledronic acid on bone mineral density around prostheses and bone metabolism markers after primary total hip arthroplasty in females with postmenopausal osteoporosis

INTRODUCTION

To investigate the effect of zoledronic acid on periprosthetic bone mineral density (BMD) and bone metabolism markers after primary total hip arthroplasty in females with postmenopausal osteoporosis.

METHODS

From November 2015 to April 2016, 40 female patients who met the inclusion criteria were randomized into two groups: a control group (calcium + calcitriol) and a zoledronic acid group (calcium + calcitriol + zoledronic acid). At 1 week and 3, 6, and 12 months after operation, BMD was obtained through dual-energy X-ray absorptiometry (DEXA). At pre-operation and at 3, 6, and 12 months after the operation, levels of bone metabolism markers were obtained by serum examination.

RESULTS

Loss of BMD was significantly more pronounced in the control group than in the ZOL group in zones 1, 4, 6, and 7 at 6 months and in zones 1, 2, 4, 6, and 7 at 12 months after the operation. The levels of bone-resorption marker (β-CTX) were significantly lower in the ZOL group than in the control group at 3, 6, and 12 months after operation. The levels of bone-formation marker (TP1NP) performed statistically differences only at 12 months after the operation in these two groups.

CONCLUSIONS

Receiving an intravenous infusion of 5 mg zoledronic acid after THA can effectively reduce periprosthetic BMD loss and improve bone remodeling in females with postmenopausal osteoporosis. Zoledronic acid significantly inhibited bone mass loss in zones 1, 2, 4, 6, and 7 after THA and inhibited bone-resorption marker (β-CTX) to improve bone remodeling. Zoledronic acid treatment is potentially important for patients with osteoporosis after THA.

Structure-Guided In Vitro to In Vivo Pharmacokinetic Optimization of Propargyl-Linked Antifolates

Pharmacokinetic/pharmacodynamic properties are strongly correlated with the in vivo efficacy of antibiotics. Propargyl-linked antifolates, a novel class of antibiotics, demonstrate potent antibacterial activity against both Gram-positive and Gram-negative pathogenic bacteria, including multidrug-resistant Staphylococcus aureus. Here, we report our efforts to optimize the pharmacokinetic profile of this class to best match the established pharmacodynamic properties. High-resolution crystal structures were used in combination with in vitro pharmacokinetic models to design compounds that not only are metabolically stable in vivo but also retain potent antibacterial activity. The initial lead compound was prone to both N-oxidation and demethylation, which resulted in an abbreviated in vivo half-life (∼20 minutes) in mice. Stability of leads toward mouse liver microsomes was primarily used to guide medicinal chemistry efforts so robust efficacy could be demonstrated in a mouse disease model. Structure-based drug design guided mitigation of N-oxide formation through substitutions of sterically demanding groups adjacent to the pyridyl nitrogen. Additionally, deuterium and fluorine substitutions were evaluated for their effect on the rate of oxidative demethylation. The resulting compound was characterized and demonstrated to have a low projected clearance in humans with limited potential for drug-drug interactions as predicted by cytochrome P450 inhibition as well as an in vivo exposure profile that optimizes the potential for bactericidal activity, highlighting how structural data, merged with substitutions to introduce metabolic stability, are a powerful approach to drug design.

Pharmacokinetics of the recombinant ovine interferon-tau in lambs

In the current study, twenty lambs, aged 4 months, half male and half female, were classified into four groups, with five in each group. The experimental three groups of lambs were given intravenous (IV), intramuscular (IM) and subcutaneous (SC) administrations of recombinant ovine interferon-τ (roIFN-τ). The fourth group (normal control) of lambs was given normal saline injections in the same way. After administrations, blood samples were collected from the tested animals at different time points post injection, and the serum titers of roIFN-τ were measured using cytopathic effect (CPE) inhibition bioassay. The results of calculating pharmacokinetic (PK) parameters using DAS software showed that the PK characteristics of roIFN-τ through IV injection conformed to the two-compartment open model, whose half-life of distribution phases (T1/2α) was 0.33±0.034 h and the elimination half-life(T1/2β) was 5.01±0.24 h. However, the PK features of IM injection and SC injection of roIFN-τ conformed to the one compartment open model, whose Tmax were 3.11±0.26 h and 4.83±0.43 h, respectively, together with an elimination half life(T1/2β) of 9.11±0.76 h and 7. 43±0.58 h, and an absorption half-life (T1/2k(a)) of 1.13±0.31 h and 1.85±0.40 h, respectively. The bioavailability of roIFN-τ after IM administration reaches 73.57%, which is greater than that of SC administration (53.43%). These results indicate that the drug administration effect can be preferably obtained following a single dose IM administration of the roIFN-τ aqueous preparation. This study will facilitate the clinical application of roIFN-τ as a potential antiviral agent in future work.