Intravenous Bolus Administration Research Articles

Pharmacokinetics and Molecular Modeling Indicate nAChRα4-Derived Peptide HAEE Goes through the Blood-Brain Barrier.

One of the treatment strategies for Alzheimer’s disease (AD) is based on the use of pharmacological agents capable of binding to beta-amyloid (Aβ) and blocking its aggregation in the brain. Previously, we found that intravenous administration of the synthetic tetrapeptide Acetyl-His-Ala-Glu-Glu-Amide (HAEE), which is an analogue of the 35–38 region of the α4 subunit of α4β2 nicotinic acetylcholine receptor and specifically binds to the 11–14 site of Aβ, reduced the development of cerebral amyloidogenesis in a mouse model of AD. In the current study on three types of laboratory animals, we determined the biodistribution and tissue localization patterns of HAEE peptide after single intravenous bolus administration. The pharmacokinetic parameters of HAEE were established using uniformly tritium-labeled HAEE. Pharmacokinetic data provided evidence that HAEE goes through the blood–brain barrier. Based on molecular modeling, a role of LRP1 in receptor-mediated transcytosis of HAEE was proposed. Altogether, the results obtained indicate that the anti-amyloid effect of HAEE, previously found in a mouse model of AD, most likely occurs due to its interaction with Aβ species directly in the brain.

Dynamic Serial Cytokine Measurements During Intravenous Ca-DTPA Chelation in Gadolinium Deposition Disease and Gadolinium Storage Condition: A Pilot Study.

The aim of this study was to investigate the feasibility of measuring early changes in serum cytokine levels after intravenous diethylenetriaminepentaacetic acid (Ca-DTPA) chelation in patients manifesting either gadolinium deposition disease (GDD) or gadolinium storage condition (GSC) and the possible usefulness of this method in further research. Four patients with recent-onset GDD (≤1 year) and 2 patients with long-standing GSC (4 and 9 years) underwent chelation with intravenous bolus administration of Ca-DTPA. Multiple blood draws were performed to measure serum cytokines: at T = 0 (before Ca-DTPA injection) and 1, 5, 10, 30, 60 minutes, and 24 hours after Ca-DTPA injection. Patients rated the severity of GDD symptom flare at 24 hours. The 24-hour urine Gd amounts were measured prechelation and for the 24 hours after chelation. Serum samples were analyzed blind to whether patients had GDD or GSC but with knowledge of the time points characterizing each sample. Urine samples for both GDD and GSC patients showed increases in Gd postchelation. All GDD patients experienced flare reactions postchelation; the 2 GSC patients did not. Two cytokines, EGF and sCD40L, peaked at 30 minutes postchelation in at least 4 of the 6 participants. Three cytokines, ENA78/CXCL5, EOTAXIN/CCL11, and LEPTIN, peaked at 24 hours in at least 4 of the 6 participants. Two participants were high outliers for a large number of cytokines across time points. No clear distinction between GDD and GSC was apparent from the cytokine patterns, although differences were present. This pilot study describes precise temporal resolution (in the range of minutes) after a cytokine-inciting event. Select cytokines exhibited peak values at different time points. At this preliminary stage of investigation, peak cytokine release seems to reflect the amount of Gd mobilized rather than the severity of the patient symptomatic reaction. Too few subjects were studied to support statistical analysis between GDD and GSC groups, although differences were observed through visual data analysis.

Improved Method of Contrast-enhanced Ultrasound examination of the Kidneys in Patients with Type 2 Diabetes Mellitus

Aim of the research. Тo evaluate the diagnostic efficacy of the contrast-enhanced ultrasound examination of kidneys in patients with type 2 diabetes mellitus with a dose of 0.5 ml of contrast agent administered.Materials and methods. We examined 12 patients with a verified diagnosis of type 2 diabetes. The age of the examined patients was 31–59 years, the mean age was 49 ± 1.3 years. All patients underwent complex diagnostics, including ultrasound examination of the kidneys in B-mode with further renal vessels color Doppler imaging to assess vessels hemodynamics. A contrast-enhanced ultrasound examination of the kidneys was carried out using Sonovue contrast agent at the doses of 2.5 ml (according to the European Good Clinical Practice Recommendations for Contrast-Enhanced Ultrasound) and 0.5 ml (an improved technique of contrast agent intravenous bolus administration).Results. The improved technique (0.5 ml of contrast agent intravenous bolus administration) in comparison with the European Recommendations technique (2.5 ml of contrast agent intravenous bolus administration) used in patients with type 2 diabetes showed no or minor differences in the qualitative and quantitative indicators of contrast-enhanced ultrasound examination which did not affect the interpretation of the results.Conclusion. The improved contrast-enhanced ultrasound examination technique using 0.5 ml of a contrast agent showed its possibilities in diagnosing diabetic nephropathy in patients with type 2 diabetes, and also revealed the potential of an economically beneficial distribution of a contrast agent without losing the quality and information content of the study.

Safety and effectiveness of intravenous procainamide in patients with frequent ventricular ectopics during cardiac magnetic resonance scanning: a way to ensure high quality imaging

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Cardiac magnetic resonance (CMR) imaging in patients with frequent ventricular arrhythmias provides significant diagnostic and prognostic information but is challenging due to artefacts. In patients with occasional ventricular premature contractions (VPCs), arrhythmia rejection algorithms can be used to acquire good quality cine images at the expense of longer breath-hold times. However, arrhythmia sorting in not practical in cases of frequent VPCs; other options include triggered data acquisition which compromises image quality or use of low temporal and spatial resolution ‘real-time’ imaging. Purpose The aim of our study was to examine the safety and effectiveness of the class Ia antiarrhythmic medication procainamide for suppressing ventricular ectopy and acquiring high quality CMR images. Methods 50 consecutive patients (mean age 48 ± 16 years; 52% female) with a high burden of VPCs during CMR scanning were included in the study. Procainamide was administered on the scanner table prior to CMR scanning at intermittent intravenous bolus doses of 50 mg every minute, until suppression of VPCs was achieved or a maximum dose of 10 mg/kg was reached. Blood pressure was measured every minute and there was continuous monitoring of heart rate and ECG trace. CMR studies were performed on a 1,5T Magnetom Avanto scanner using a standard cardiac protocol. Results The average dose of procainamide administered was 567 ± 197 mg (range 200-1000 mg). Procainamide successfully suppressed VPCs in 82% of patients (20 patients with complete suppression and 21 with significant reduction); 7 patients had minimal suppression of VPCs, while there was no effect of procainamide in only 2 patients. Baseline blood pressure (BP) was mildly reduced (mean change systolic BP -12 ± 9 mmHg; diastolic BP -4 ± 9 mmHg) but none of the patients developed symptomatic hypotension. Baseline heart rate (HR) was relatively unchanged (baseline 75 ± 11 beats per minute (bpm) – peak procainamide HR 74 ± 12 bpm (mean HR change -1 ± 6 bpm). None of the patients developed pathological ECG changes. CMR scan had normal findings in 42% of the patients, 26% had non-ischemic cardiomyopathy, in 16% the most likely diagnosis was VPC-related cardiomyopathy, 14% had previous myocarditis, and 1 patient had dual pathology (dilated cardiomyopathy with previous myocardial infarction). Mean left ventricular ejection fraction was 55% ± 9%. Conclusion We propose the bolus intravenous administration of procainamide prior to CMR scanning as a safe and effective alternative approach for suppressing VPCs and acquiring high quality images in patients with frequent ventricular arrhythmias and normal or only mildly impaired left ventricular function. Further studies are needed to assess its safety and effectiveness in larger patient cohorts, including also patients with ventricular systolic impairment.

Bolus Intravenous Procainamide in Patients with Frequent Ventricular Ectopics during Cardiac Magnetic Resonance Scanning: A Way to Ensure High Quality Imaging.

Acquiring high-quality cardiac magnetic resonance (CMR) images in patients with frequent ventricular arrhythmias remains a challenge. We examined the safety and efficacy of procainamide when administered on the scanner table prior to CMR scanning to suppress ventricular ectopy and acquire high-quality images. Fifty consecutive patients (age 53.0 [42.0–58.0]; 52% female, left ventricular ejection fraction 55 ± 9%) were scanned in a 1.5 T scanner using a standard cardiac protocol. Procainamide was administered at intermittent intravenous bolus doses of 50 mg every minute until suppression of the ectopics or a maximum dose of 10 mg/kg. The average dose of procainamide was 567 ± 197 mg. Procainamide successfully suppressed premature ventricular contractions (PVCs) in 82% of patients, resulting in high-quality images. The baseline blood pressure (BP) was mildly reduced (mean change systolic BP −12 ± 9 mmHg; diastolic BP −4 ± 9 mmHg), while the baseline heart rate (HR) remained relatively unchanged (mean HR change −1 ± 6 bpm). None of the patients developed proarrhythmic changes. Bolus intravenous administration of procainamide prior to CMR scanning is a safe and effective alternative approach for suppressing PVCs and acquiring high-quality images in patients with frequent PVCs and normal or only mildly reduced systolic function.

Comment on a Recent Article Titled “Irisin Correlates Positively With BMD in a Cohort of Older Adult Patients and Downregulates the Senescent Marker p21 in Osteoblasts”

In a recent issue of JBMR, Colaianni and colleagues reported the relationship of circulating irisin levels, a myokine synthesized from skeletal muscle, with bone and muscle parameters in a sample of older adults.(1) They showed that FNDC5 expression, an irisin precursor, in muscle biopsies positively correlated with osteocalcin mRNA in bone biopsies, suggesting a connection between these tissues. Interestingly, the treatment with irisin decreased p21 mRNA expression, a senescence marker, in osteoblasts in vitro. These findings may be a guide for novel therapeutic approaches to delaying age-related muscle atrophy and bone loss. However, a few points are worth discussing. The authors may not have accounted for several factors that could influence their results, including chronic diseases and some selected drugs. The prevalence of chronic conditions increases after the age of 60 years, and many older people develop more than one chronic disease. A recent cross-sectional study of 740 participants showed an association of serum irisin with adiposity, glucose tolerance, and insulin resistance in middle-aged individuals.(2) In the same study, patients with diabetes mellitus (DM) had lower irisin levels than those without DM.(2) Correspondingly, serum irisin concentrations significantly decreased among patients with DM in a cohort of adults older than 60 years.(3) On the other hand, experimental studies showed that bolus intravenous administration of irisin decreased arterial blood pressure by reducing vascular endothelial dysfunction via upregulation of NO synthesis and activating the AMPK-Akt-eNOS pathway.(4, 5) Lower circulating irisin levels were found to be associated with high systolic and diastolic blood pressure in patients with preeclampsia.(6) Besides, cardiac muscles are an important source of irisin synthesis, and the change in heart function may alter the production of this protein.(7) Many older individuals are prescribed drugs to manage chronic diseases. Metformin therapy is the first-line agent in the treatment of DM in older individuals. In an interventional study of patients with polycystic ovary syndrome, 3 months of metformin treatment decreased serum irisin levels and improved insulin resistance.(8) Lowering blood pressure with amlodipine and valsartan increased the circulating levels of irisin in patients with untreated essential hypertension.(9) An animal study showed that statin treatment increased irisin levels in skeletal muscle.(10) I would like to ask the authors whether they provide some data on this population's comorbidities and medication for diabetes mellitus, hypertension, and hyperlipidemia. Inclusion of new data in statistical analysis could help make the results stronger. New findings could raise the importance of this research, which aimed to explore the role of irisin in bone and muscle senescence.

Pharmacokinetic\u2013pharmacodynamic modelling of the hypoglycaemic effect of pulsatile administration of human insulin in rats

The relationship between the plasma insulin (INS) concentration–time course and plasma glucose concentration–time course during and after pulsatile INS administration to rats was characterized using a pharmacokinetic–pharmacodynamic (PK–PD) model. A total INS dose of 0.5 IU/kg was intravenously injected in 2 to 20 pulses over a 2-h period. Compared with the single bolus administration, the area under the effect-time curve (AUE) increased depending on the number of pulses, and the AUEs for more than four pulses plateaued at a significantly larger value, which was similar to that after the infusion of a total of 0.5 IU/kg of INS over 2 h. No increase in plasma INS concentration occurred after pulsatile administration. Two indirect response models primarily reflecting the receptor-binding process (IR model) or glucose transporter 4 (GLUT4) translocation (GT model) were applied to describe the PK–PD relationship after single intravenous bolus administration of INS. These models could not explain the observed data after pulsatile administration. However, the IR-GT model, which was a combination of the IR and GT models, successfully explained the effects of pulsatile administration and intravenous infusion. These results indicate that the receptor-binding process and GLUT4 translocation are responsible for the change in AUE after pulsatile administration.

Mechanism and Management of Fentanyl-Induced Cough.

Fentanyl-induced cough (FIC) often occurs after intravenous bolus administration of fentanyl analogs during induction of general anesthesia and analgesia procedure. The cough is generally benign, but sometimes it causes undesirable side effects, including elevated intra-abdominal, intracranial or intraocular pressure. Therefore, understanding the related mechanisms and influencing factors are of great significance to prevent and treat the cough. This paper reviews the molecular mechanism, influencing factors and preventive administration of FIC, focusing on the efficacy and side effects of various drugs in inhibiting FIC to provide some medical reference for anesthesiologists.

Intracoronary Versus Intravenous Administration of Eptifibatide During Percutaneous Coronary Intervention in Patients With Acute Coronary Syndromes

Platelet activation and aggregation play a major role in thrombosis formation of coronary arteries in patients with Acute Coronary Syndrome (ACS) and is responsible for most ischemic complications during PCI. There is little information on the benefits and side effects of intracoronary and intravenous injection of Eptifibatide, a potent antiplatelet agent; therefore, this study was performed with the aim to compare coronary blood flow velocity by measurement of TIMI frame count. In intravenous versus intracoronary bolus administration of Eptifibatide during PCI in ACS patients. This non-randomized clinical trial study was performed on 103 patients with acute coronary syndromes who referred to the cardiac emergency ward of Ghaem hospital, Mashhad University of Medical Sciences, and were candidates for urgent coronary angiography and PCI. Forty-eight cases received intracoronary bolus Eptifibatide and 55 intravenous Eptifibatide. TIMI Frame Count and Corrected TIMI Frame Count were used to comparing the effect of these two methods on coronary blood flow velocity. Data were analyzed by SPSS software (version 22). To compare the quantitative variables in the two groups, according to the distribution of variables, the t-test was used if it was normal or the Mann-Whitney test was used if it was not normal. A Chi-square test was also used to compare qualitative variables into two groups. P<0.05 was considered statistically significant. Mean of age, gender, and cardiovascular risk factors were similar in the two groups. There was no significant difference in terms of serum Creatine Kinase MB (CKMB) level, Left Ventricular Ejection Fraction (LVEF), coronary artery lesion length, coronary artery diameter, coronary thrombosis, and coronary artery thrombectomy in two groups. Based on Student's t-test, there was no significant difference between mean TIMI Frame Count in different coronary arteries in the intracoronary and intravenous injection groups (In LAD, P=0.518; For LCX, P=0.576; and in RCA, P=0.964). The complications were observed in 11 patients (22.9%) of the intracoronary injection group and 9 (16.4%) of the intravenous injection group; the difference was not significant (P=0.402). The effects and complications of Eptifibatide were not significantly different in Intracoronary and intravenous administration in ACS patients during PCI and at the time of patients' hospitalization.

Give Intravenous Bolus Overdose a Brake: User Experience and Perception of Safety Device.

ObjectivesDrugs can come in concentrated solutions that require dilution before intravenous bolus administration. Upon dilution, the syringe can contain more than the required amount of drug. The user may mistakenly administer the full contents of the syringe, resulting in an overdose. In this cross-sectional study, we evaluated user experience and perception of Syringe Brake, a dosage flow restrictor device, as part of the intravenous morphine bolus administration workflow.MethodsFrom December 2018 to January 2019, doctors and nurses working in the emergency department of 3 public tertiary hospitals in Singapore were invited to complete a paper-based 11-item 5-point Likert scale survey questionnaire after 3 months of Syringe Brake implementation.ResultsOverall, 77.5% (290/374; 4.11 ± 0.83) of participants were satisfied with the use of Syringe Brake to prevent medication error. Our survey results showed that the top features of Syringe Brake were ease of setting the desired volume to be administered (86.1%; 4.21 ± 0.72), allowing the drug to be titrated safely (84.8%; 4.26 ± 0.77), and giving users the confidence to avoid overdosing the patient (82.1%; 4.21 ± 0.78). Those with hands-on experience with Syringe Brake rated significantly higher for all survey statements except on the perceived ability to prevent error arising from miscommunication (adjusted odds ratio, 1.58 [0.98–2.57]; P = 0.062).ConclusionsSyringe Brake shows promising potential for adoption to prevent medication errors. The device serves as a constraint to prevent accidental overdose, caused by user unfamiliarity or autopilot administration.

The Effectiveness of Tranexamic Acid in Patients With Proximal Femoral Tumor Resection Prosthesis.

Aim: The aim of this study is to evaluate the risk of thromboembolic events and amount of postoperative blood loss and transfusion in patients who received preoperative tranexamic acid (TXA) administration in proximal femoral resection and endoprosthesis of proximal femur malignant lesion.Methods: In this study, the data of 46 patients who underwent extensive resection and proximal femoral tumor prosthesis for proximal femoral bone malignancies were retrospectively reviewed. Patients were divided into two groups according to preoperative 15 mg/kg bolus intravenous administration of TXA. These patients were compared in terms of postoperative blood loss, postoperative bleeding, and transfusion requirements.Results: There were 46 patients (18 female, 28 male) with a mean age of 60.7±14.7 (19-89) years. Fifteen patients (32.6%) were treated with iv TXA. In the TXA group (46.7%), there was a statistically significant decrease in the need for transfusion compared to the patient group (93.5%) without TXA (p=0.001). Postoperative 24th hour, 48th hour,and total drainage blood loss values were found to be significantly lower in the TXA group (p=0.047, p=0.015, and p=0.019, respectively). There was no thromboembolic event observed.Conclusion: Because of proximal femoral malignancy, extensive tumor resection and preoperative bolus 15 mg/kg TXA administration in proximal femoral prosthesis surgery significantly decreased the amount of postoperative bleeding and transfusion requirement without increasing the risk of thromboembolic event.Level of Evidence: Level III - retrospective comparative study.

Evaluating acute inflammation's effects on hepatic triglyceride content in experimentally induced hyperlipidemic dairy cows in late lactation

Inflammation appears to be a predisposing factor and key component of hepatic steatosis in a variety of species. Objectives were to evaluate effects of inflammation [induced via intravenous lipopolysaccharide (LPS) infusion] on metabolism and liver lipid content in experimentally induced hyperlipidemic lactating cows. Cows (765 ± 32 kg of body weight; 273 ± 35 d in milk) were enrolled in 2 experimental periods (P); during P1 (5 d), baseline data were obtained. At the start of P2 (2 d), cows were assigned to 1 of 2 treatments: (1) intralipid plus control (IL-CON; 3 mL of saline; n = 5) or (2) intralipid plus LPS (IL-LPS; 0.375 μg of LPS/kg of body weight; n = 5). Directly following intravenous bolus (saline or LPS) administration, intralipid (20% fat emulsion) was intravenously infused continuously (200 mL/h) for 16 h to induce hyperlipidemia during which feed was removed. Blood samples were collected at -0.5, 0, 4, 8, 12, 16, 24, and 48 h relative to bolus administration, and liver biopsies were obtained on d 1 of P1 and at 16 and 48 h after the bolus. By experimental design (feed was removed during the first 16 h of d 1), dry matter intake decreased in both treatments on d 1 of P2, but the magnitude of reduction was greater in LPS cows. Dry matter intake of IL-LPS remained decreased on d 2 of P2, whereas IL-CON cows returned to baseline. Milk yield decreased in both treatments during P2, but the extent and duration was longer in LPS-infused cows. Administering LPS increased circulating LPS-binding protein (2-fold) at 8 h after bolus, after which it markedly decreased (84%) below baseline for the remainder of P2. Serum amyloid A concentrations progressively increased throughout P2 in IL-LPS cows (3-fold, relative to controls). Lipid infusion gradually increased nonesterified fatty acids and triglycerides in both treatments relative to baseline (3- and 2.5-fold, respectively). Interestingly, LPS infusion blunted the peak in nonesterified fatty acids, such that concentrations peaked (43%) higher in IL-CON compared with IL-LPS cows and heightened the increase in serum triglycerides (1.5-fold greater relative to controls). Liver fat content remained similar in IL-LPS relative to P1 at 16 h; however, hyperlipidemia alone (IL-CON) increased liver fat (36% relative to P1). No treatment differences in liver fat were observed at 48 h. In IL-LPS cows, circulating insulin increased markedly at 4 h after bolus (2-fold relative to IL-CON), and then gradually decreased during the 16 h of lipid infusion. Inducing inflammation with simultaneous hyperlipidemia altered the characteristic patterns of insulin and LPS-binding protein but did not cause fatty liver.

Aldophosphamide-thiazolidine (NSC-613060) an oxazaphosphorine cytostatic that crosses the blood brain barrier

The pharmacologically active metabolite of cyclophosphamide is aldophosphamide. With cysteine, aldophosphamide forms stable aldophosphamide-thiazolidine which under physiological pH and temperature conditions hydrolyzes to aldophosphamide and cysteine. Aldophosphamide-thiazolidine was synthesized and tested for its ability as a cytostatic. The LD50 after a single intraperitoneal injection in mice was determined to be 2162 mg/kg, but after intravenous bolus administration of 500 mg/kg or in chronic toxicity tests with daily intraperitoneal injections, neurological side effects were observed. Antitumor activity was determined in therapy experiments in CD2F1 mice bearing subcutaneously transplanted P388 mouse leukemia cells. Administration of 100 mg/kg (less than 5% LD50) days 1-5 after tumor transplantation yielded an ILS of 100%. Organ distribution studies showed that aldophosphamide-thiazolidine is evenly distributed in all tissues examined, including brain tissue. The possibilities to increase the antitumor activity of aldophosphamide-thiazolidine by modulating the alkylating function are discussed.

Development and validation of a cost-effective and sensitive bioanalytical HPLC-UV method for determination of lopinavir in rat and human plasma.

A simple, sensitive and cost-effective HPLC-UV bioanalytical method for determination of lopinavir (LPV) in rat and human plasma was developed and validated. The plasma sample preparation procedure includes a combination of protein precipitation using cold acetonitrile and liquid-liquid extraction with n-hexane-ethyl acetate (7:3, v/v). A good chromatographic separation was achieved with a Phenomenex Gemini column (C18 , 150 mm × 2.0 mm, 5 μm) at 40°C with gradient elution, at 211 nm. Calibration curves were linear in the range 10-10,000 ng/mL, with a lower limit of quantification of 10 ng/mL using 100 μL of plasma. The accuracy and precision in all validation experiments were within the criteria range set by the guidelines of the Food and Drug Administration. This method was successfully applied to a preliminary pharmacokinetic study in rats following an intravenous bolus administration of LPV. Moreover, the method was subsequently fully validated for human plasma, allowing its use in therapeutic drug monitoring (TDM). In conclusion, this novel, simple and cost-efficient bioanalytical method for determination of LPV is useful for pharmacokinetic and drug delivery studies in rats, as well as TDM in human patients.

Targeted Ultrasound Contrast Imaging of Tumor Vasculature With Positively Charged Microbubbles.

Molecular ultrasound imaging of tumor vasculature is being actively investigated with microbubble contrast agents targeted to neovasculature biomarkers. Yet, a universal method of targeting tumor vasculature independent of specific biomarkers, or in their absence, would be desirable. We report the use of electrostatic interaction to achieve adherence of microbubbles to tumor vasculature and resulting tumor delineation by ultrasound imaging. Microbubbles were prepared from decafluorobutane gas by amalgamation of aqueous micellar medium. Distearoyl phosphatidylcholine (DSPC) and polyethylene glycol (PEG)-stearate were used as microbubble shell-forming lipids; cationic lipid distearoyl trimethylammoniumpropane (DSTAP) was included to introduce positive electrostatic charge. Microbubbles were subjected to flotation in normal gravity, to remove larger particles. Murine colon adenocarcinoma tumor (MC38, J. Schlom, National Institutes of Health) was inoculated in the hind leg of C57BL/6 mice. Contrast ultrasound imaging was performed under isoflurane anesthesia, using a clinical imaging system in low power mode, with tissue signal suppression (contrast pulse sequencing, 7 MHz, 1 Hz; Mechanical Index, 0.2). The ultrasound probe was positioned to monitor the tumor and contralateral leg muscle; microbubble contrast signal was monitored for 30 minutes or more, after intravenous bolus administration of 2.10 microbubbles. Individual time point frames were extracted from ultrasound video recording and analyzed with ImageJ. Mean bubble diameter was ~1.6 to 2 μm; 99.9% were less than 5 μm, to prevent blocking blood flow in capillaries. For cationic DSTAP-carrying microbubbles, contrast signal was observed in the tumor beyond 30 minutes after injection. As the fraction of positively charged lipid in the bubble shell was increased, adherent contrast signal in the tumor also increased, but accumulation of DSTAP-microbubbles in the normal muscle increased as well. For bubbles with the highest positive charge tested, DSTAP-DSPC molar ratio 1:4, at 10 minutes after intravenous administration of microbubbles, the contrast signal difference between the tumor and normal muscle was 1.5 (P < 0.005). At 30 minutes, tumor/muscle contrast signal ratio improved and reached 2.1. For the DSTAP-DSPC 1:13 preparation, tumor/muscle signal ratio exceeded 3.6 at 10 minutes and reached 5.4 at 30 minutes. Microbubbles with DSTAP-DSPC ratio 1:22 were optimal for tumor targeting: at 10 minutes, tumor/muscle signal ratio was greater than 7 (P < 0.005); at 30 minutes, greater than 16 (P < 0.01), sufficient for tumor delineation. Cationic microbubbles are easy to prepare. They selectively accumulate in the tumor vasculature after intravenous administration. These microbubbles provide target-to-control contrast ratio that can exceed an order of magnitude. Adherent microbubbles delineate the tumor mass at extended time points, at 30 minutes and beyond. This may allow for an extension of the contrast ultrasound examination time. Overall, positively charged microbubbles could become a universal ultrasound contrast agent for cancer imaging.

P0379BION-1301, A FULLY BLOCKING ANTIBODY TARGETING APRIL FOR THE TREATMENT OF IGA NEPHROPATHY: ASSESSMENT OF SAFETY, PHARMACOKINETICS AND PHARMACODYNAMICS IN LONG-TERM NONCLINICAL STUDIES

Abstract Background and Aims IgA Nephropathy (IgAN) is a common form of glomerulonephritis and its pathogenesis is thought to consist of sequential pathogenic hits, including the production of auto-antigen galactose-deficient IgA1 (Gd-IgA1) and auto-antibody formation ultimately resulting in immune complex deposition, inflammation and functional deterioration of the kidney. Serum levels of APRIL (A PRoliferation Inducing Ligand, TNFSF13) and levels of Gd-IgA1 are correlated with severity of disease (Zhao et al, 2012). As a ligand for the receptors BCMA and TACI, APRIL is thought to regulate differentiation and proliferation of B cells and plasma cells and IgA class switching. BION-1301 is a humanized antibody neutralizing APRIL. In nonhuman primates, BION-1301 reduced serum levels of IgA, IgM, and IgG with no drug-related toxicity (Dulos J, et al. ASN Annual Meeting. 2018). Here we describe the nonclinical safety assessment of BION-1301, to support its continued clinical development for the treatment of IgA Nephropathy. Method A 14-week repeat-dose toxicity and toxicokinetic/pharmacodynamic (TK/PD) study in non-human primates (NHP) was performed by biweekly intravenous bolus (IV) administration of BION-1301 at three different dose levels. To support a potential change in route of administration, a 4-week repeat-dose NHP bridging study was conducted with weekly subcutaneous (SC) administration of BION-1301 at three different dose levels. Results In both the 14-week IV study and the 4-week SC study, BION-1301 was evaluated for safety, TK and PD. For TK and PD, BION-1301 levels, uncomplexed APRIL levels and immunoglobulin levels (IgA, IgG, IgM) were quantified in serum. Immunophenotyping was performed on peripheral blood to assess the impact of BION-1301 on the B cell compartment. In both studies BION-1301 was well tolerated with no test-article related findings. 14-week IV dosing as well as 4-week SC dosing of BION-1301 reduced serum APRIL levels as well as serum immunoglobulin levels. Conclusion Results of these nonclinical toxicity studies with toxicology, TK and PD endpoints demonstrate that BION-1301 is well tolerated for up to 14 weeks of dosing, corroborates pharmacodynamic proof-of-mechanism and support prolonged dosing and SC administration of BION-1301 in patients with IgA Nephropathy.

Pharmacokinetics of xylazine after 2-, 4-, and 6-hr durations of continuous rate infusions in horses.

Intravenous (i.v.) bolus administration of xylazine (XYL) (0.5mg/kg) immediately followed by a continuous rate infusion (CRI) of 1mgkg-1 hr-1 for 2, 4, and 6hr produced immediate sedation, which lasted throughout the duration of the CRI. Heart rate decreased and blood pressure increased significantly (p>.05) in all horses during the first 15min of infusion, both returned to and then remained at baseline during the duration of the infusion. Compartmental models were used to investigate the pharmacokinetics of XYL administration. Plasma concentration-time curves following bolus and CRI were best described by a one-compartment model. No differences were found between pharmacokinetic estimates of the CRIs for the fractional elimination rate constant (Ke ), half-life (t1/2e ), volume of distribution (Vd ), and clearance (Cl). Median and range were 0.42 (0.15-0.97)/hr, 1.68 (0.87-4.52)hr, 5.85 (2.10-19.34)L/kg, and 28.7 (19.6-39.5)mlmin-1 kg-1 , respectively. Significant differences were seen for area under the curve ( ) (p<.0002) and maximum concentration (Cmax ) (p<.04). This indicates that with increasing duration of infusion, XYL may not accumulate in a clinically relevant way and hence no adjustments are required in a longer XYL CRI to maintain a constant level of sedation and a rapid recovery.

Prevention of Adrenal Crisis: Cortisol Responses to Major Stress Compared to Stress Dose Hydrocortisone Delivery

ContextPatients with adrenal insufficiency require increased hydrocortisone cover during major stress to avoid a life-threatening adrenal crisis. However, current treatment recommendations are not evidence-based.ObjectiveTo identify the most appropriate mode of hydrocortisone delivery in patients with adrenal insufficiency who are exposed to major stress.Design and ParticipantsCross-sectional study: 122 unstressed healthy subjects and 288 subjects exposed to different stressors (major trauma [N = 83], sepsis [N = 100], and combat stress [N = 105]). Longitudinal study: 22 patients with preserved adrenal function undergoing elective surgery. Pharmacokinetic study: 10 patients with primary adrenal insufficiency undergoing administration of 200 mg hydrocortisone over 24 hours in 4 different delivery modes (continuous intravenous infusion; 6-hourly oral, intramuscular or intravenous bolus administration).Main Outcome MeasureWe measured total serum cortisol and cortisone, free serum cortisol, and urinary glucocorticoid metabolite excretion by mass spectrometry. Linear pharmacokinetic modeling was used to determine the most appropriate mode and dose of hydrocortisone administration in patients with adrenal insufficiency exposed to major stress.ResultsSerum cortisol was increased in all stress conditions, with the highest values observed in surgery and sepsis. Continuous intravenous hydrocortisone was the only administration mode persistently achieving median cortisol concentrations in the range observed during major stress. Linear pharmacokinetic modeling identified continuous intravenous infusion of 200 mg hydrocortisone over 24 hours, preceded by an initial bolus of 50–100 mg hydrocortisone, as best suited for maintaining cortisol concentrations in the required range.ConclusionsContinuous intravenous hydrocortisone infusion should be favored over intermittent bolus administration in the prevention and treatment of adrenal crisis during major stress.

Varespladib (LY315920) and Methyl Varespladib (LY333013) Abrogate or Delay Lethality Induced by Presynaptically Acting Neurotoxic Snake Venoms.

The phospholipase A2 (PLA2) inhibitor Varespladib (LY315920) and its orally bioavailable prodrug, methyl-Varespladib (LY333013) inhibit PLA2 activity of a wide variety of snake venoms. In this study, the ability of these two forms of Varespladib to halt or delay lethality of potent neurotoxic snake venoms was tested in a mouse model. The venoms of Notechis scutatus, Crotalus durissus terrificus, Bungarus multicinctus, and Oxyuranus scutellatus, all of which have potent presynaptically acting neurotoxic PLA2s of variable quaternary structure, were used to evaluate simple dosing regimens. A supralethal dose of each venom was injected subcutaneously in mice, followed by the bolus intravenous (LY315920) or oral (LY333013) administration of the inhibitors, immediately and at various time intervals after envenoming. Control mice receiving venom alone died within 3 h of envenoming. Mice injected with O. scutellatus venom and treated with LY315920 or LY333013 survived the 24 h observation period, whereas those receiving C. d. terrificus and B. multicinctus venoms survived at 3 h or 6 h with a single dose of either form of Varespladib, but not at 24 h. In contrast, mice receiving N. scutatus venom and then the inhibitors died within 3 h, similarly to the control animals injected with venom alone. LY315920 was able to reverse the severe paralytic manifestations in mice injected with venoms of O. scutellatus, B. multicinctus, and C. d. terrificus. Overall, results suggest that the two forms of Varespladib are effective in abrogating, or delaying, neurotoxic manifestations induced by some venoms whose neurotoxicity is mainly dependent on presynaptically acting PLA2s. LY315920 is able to reverse paralytic manifestations in severely envenomed mice, but further work is needed to understand the significance of species-specific differences in animal models as they compare to clinical syndromes in human and for potential use in veterinary medicine.

Dose-Finding Study and Pharmacokinetics Profile of the Novel 13-Mer Antisense miR-221 Inhibitor in Sprague-Dawley Rats

miR-221 is overexpressed in several malignancies where it promotes tumor growth and survival by interfering with gene transcripts, including p27Kip1, PUMA, PTEN, and p57Kip2. We previously demonstrated that a novel 13-mer miR-221 inhibitor (locked nucleic acid [LNA]-i-miR-221) exerts antitumor activity against human cancer with a pilot-favorable pharmacokinetics and safety profile in mice and non-naive monkeys. In this study, we report a non-good laboratory practice (GLP)/GLP dose-finding investigation of LNA-i-miR-221 in Sprague-Dawley rats. The safety of the intravenous dose (125 mg/kg/day) for 4 consecutive days, two treatment cycles, was investigated by a first non-GLP study. The toxicokinetics profile of LNA-i-miR-221 was next explored in a GLP study at three different doses (5, 12.5, and 125 mg/kg/day). Slight changes in blood parameters and histological findings in kidney were observed at the highest dose. These effects were reversible and consistent with an in vivo antisense oligonucleotide (ASO) class effect. The no-observed-adverse-effect level (NOAEL) was established at 5 mg/kg/day. The plasma exposure of LNA-i-miR-221, based on C0 (estimated concentration at time 0 after bolus intravenous administration) and area under the curve (AUC), suggested no differential sex effect. Slight accumulation occurred between cycles 1 and 2 but was not observed after four consecutive administrations. Taken together, our findings demonstrate a safety profile of LNA-i-miR-221 in Sprague-Dawley rats and provide a reference translational framework and path for the development of other LNA miR inhibitors in phase I clinical study.