Subcutaneous Bolus Research Articles

Positive effects of ferric iron on the systemic efficacy of nephrilin peptide in burn trauma.

Introduction:Nephrilin peptide is a designed inhibitor of Rictor complex (also known as mTORC2), an evolutionarily conserved assembly believed to modulate responses to cellular stress. We previously demonstrated the ability of nephrilin peptide to suppress neuroinflammation, loss of body mass, glycaemic control and kidney function in a rat scald model, as well as sepsis mortality in a mouse model. The present study explores the effect of nephrilin plus iron formulations on clinically relevant outcomes in the rat scald model.Methods:Animals were treated with nephrilin by subcutaneous bolus injection on post-burn days 1–7. Equimolar ferric iron in the formulation improved the positive systemic effects of nephrilin on kidney function, glycaemic control, oxidative stress, early hyperinflammation, late inflammasome activation, hyperangiogenesis and body mass, all variables previously shown to bear upon clinically relevant burn injury outcomes. The sparing effects of nephrilin-iron were demonstrated in both sexes.Discussion:Surprisingly, optimum daily treatment doses were in the range of 2–4 mg/kg, while 8 mg/kg was less effective, suggesting the possibility of marginal pro-oxidant effects from the ‘free’ iron fraction. Thus, although ferric iron in the nephrilin formulation is clearly helpful, care must be exercised to select an optimum treatment dose.Conclusion:Iron increases the efficacy of nephrilin peptide in burns.

Transcriptional re-programming in rat central nervous system two weeks after burn trauma: the impact of nephrilin treatment on the expression of oxidative stress-related genes.

Introduction:Survivors of severe burns suffer lifetime neuroinflammatory consequences manifested by higher incidence of major depression and neurodegenerative disease. In a scald model, nephrilin peptide has previously been shown to protect rats from loss of lean body mass, kidney function and glycaemic control, complications that have also been shown to endure in burn patient populations. Nephrilin’s mechanism of action has been suggested to involve protection from excessive oxidative stress.Methods:Using quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) amplification of transcripts in total RNA extracted from dorsal root ganglia of male rats 14 days after exposure to thermal insult, we query the relative levels of expression of 34 genes believed to be associated with oxidative stress biology in the central nervous system (CNS). We use these data to explore the central role of oxidative stress in astrogliosis, immunosuppression and mitochondrial homeostasis.Results and Discussion:Rats that received nephrilin treatment (4 mg/kg by subcutaneous bolus injection once daily for seven days after scald injury) showed significantly reduced elevations in gene expression of some key genes such as NOX2, GFAP, AQP4 and RAC1, but not of others such as NOX4, STEAP4, ARG1 and CCL2.Conclusion:The implications of these data with reference to nephrilin’s potential clinical utility for mitigating the enduring effects of burn trauma on the CNS are discussed. Nephrilin reduces the expression of some genes implicated in neurodegeneration after burn insult.Lay SummaryNephrilin peptide is a novel treatment for short- and long-term systemic effects of burn trauma. This study measures the capability of nephrilin to address post-traumatic neurodegenerative disease by looking at the expression of genes in the central nervous system, in a rat scald model. Nephrilin appears to have beneficial effects by reducing the expression of some key genes known to be relevant in neurodegenerative processes, but not others.

Pharmacokinetic and Pharmacodynamic Properties of a Micro-Dose Nasal Spray Formulation of Desmopressin (AV002) in Healthy Water-Loaded Subjects

PurposeAntidiuretic therapy with desmopressin for nocturia has been hampered by formulations with high doses, low bioavailability and variable pharmacokinetics. AV002 (SER120), a novel, emulsified, microdose desmopressin nasal spray, with a permeation enhancer (cylcopentadecanolide), was developed to have pharmacokinetic characteristics suitable for nocturia treatment.MethodsTwelve healthy subjects participated in an open-label, dose-escalating study. Water-loaded subjects were sequentially dosed every 48 h with AV002 0.5, 1.0, 2.0 μg and 0.12 μg desmopressin subcutaneous (SC) bolus injection.ResultsAV002 intranasal administration produced a time-to-maximum concentration (Tmax) between 15 and 30 min and a maximum concentration (Cmax) <10 pg/mL. Cmax and area under the curve showed dose proportionality. Coefficient of variation for AV002 was similar to that observed for the SC dose. Bioavailability of AV002 was approximately 8% compared to SC injection. AV002 demonstrated pharmacodynamic effects within 20 min of dosing and showed increasing magnitude and duration with escalating doses. AV002 2.0 μg had maximum median urine osmolality of 629 mOsm/kg and median urine output ≤2 mL/min for 5–6 h.ConclusionsAV002 demonstrated rapid absorption, high bioavailability, limited duration of action, and low coefficient of variation, suggesting it may be a suitable formulation for nocturia treatment.Trial registration not required (single-center, phase 1).

SUN-LB036 Diabetic Ketoacidosis: A Rare Side Effect of Nivolumab Induced Insulin Dependent Diabetes Mellitus

Introduction: Nivolumab, is a monoclonal antibody directed against programmed cell death-1 receptor (anti PD-1), and is used in adjuvant treatment of melanoma. With the widespread use of immunotherapies, the incidence of autoimmune diseases referred to as immune related adverse events (irAE) is also increasing. Our case highlights a rare side effect of autoimmune insulin dependent diabetes mellitus (IDDM) related to immunotherapy, in a patient with no detectable diabetes related antibodies. We also review management of this rare side effect. Clinical Case: A 52-year-old woman with a diagnosis of stage IIIC malignant melanoma and no previous history of diabetes mellitus presented with abdominal pain and nausea. She had received 10 doses of Nivolumab as adjuvant therapy for melanoma. She denied any family history of diabetes or autoimmune disorders. Physical exam including vital signs was normal. Lab work up was significant for blood glucose of 280 mg/dl and glycated hemoglobin (HbA1c) was 7.4%, and additional blood work up showed low serum C-peptide 0.5 ng/ml (normal range 1.1-4.4 ng/mL) and negative results were obtained for all islet cell autoantibodies. Arterial blood gas (ABG) revealed high anion gap metabolic acidemia with pH 7.11, pCO2 25 mm Hg, bicarbonate (HCO3) 12 mmol/L, high anion gap 22 and serum lactate 0.8 mmol/L, consistent with diabetic ketoacidosis (DKA). Prior to initiation of Nivolumab, her HbA1c was 5.7%. The patient was diagnosed with DKA due to autoimmune-mediated IDDM secondary to Nivolumab therapy. She was treated with an insulin drip and intravenous fluids after which the anion gap and her symptoms resolved. She was discharged home with a subcutaneous basal bolus insulin regimen. Conclusion: Immunotherapies such as Nivolumab can cause new onset IDDM by inducing autoimmune response. Most likely mechanism of developing IDDM in patients treated with Nivolumab is inappropriate activation of T cells leading to destruction of pancreatic islet cells. Our patient had low serum C-peptide level which correlates with low insulin secretion suggestive of islet cell destruction. Median time of onset of IDDM is 4.4 months after starting Nivolumab. Most common endocrinopathies associated with Nivolumab are hypophysitis, thyroiditis or primary adrenal insufficiency. New onset IDDM is very uncommon irAE, and so far it has been reported in less than 1% of patients. In contrast to other irAE such as colitis there is limited data regarding role of high dose steroids in autoimmune diabetes and it can even exacerbate hyperglycemia and DKA.

MON-537 Fusion of Parathyroid Hormone to Growth Hormone Binding Protein Delays Clearance Whilst Retaining Biological Activity

Parathyroid hormone (PTH) is an 84 aa peptide and biological activity resides in residues 1-34. PTH 1-84 (Natpara) is licensed for treatment of hypoparathyroidism replacement but requires daily injections and is complicated by fluctuating calcium levels. There is an unmet need for a long acting PTH that provides constant physiological levels of PTH bioactivity. We have tested whether fusions of human PTH 1-34 to growth hormone binding protein (GHBP) could generate long acting PTH molecules. Two PTH fusion molecules were constructed: Fusion-1 consists of PTH (1-34) linked to GHBP (residues 1-238), and Fusion-2 consists of human PTH (1-34) linked to the N-terminal PTH receptor domain (PTHrExt, residues 29-187) and GHBP (residues 1-238). Fusions were expressed as secreted products from a CHO cell line and purified using a combination of ion exchange and affinity chromatography. In vitro bioactivity was measured using a Dual Luciferase Reporter Assay (DLRA), using the rat osteoblast-like cell line, UMR-106. Both fusions showed biological activity when compared to PTH 1-34 with an EC50 nM (mean ± SD) for PTH 1-34 of 40 ± 15.66, Fusion-1, 151 ± 5.85, & Fusion-2, 721 ± 307. PTH was 3.8-fold more active than Fusion-1 and 18-fold more active than Fusion-2; although, Fusion-2 showed a consistently higher maximal fold induction compared to both PTH and Fusion-1. A pharmacokinetic (PK) study for Fusion-1 was conducted in Crl:WI(Han) male rats (n = 6) by administering a single subcutaneous bolus injection at 10 nmol/kg. Serum samples were analysed for the presence of Fusion-1 using an in-house Elisa. A Cmax (mean ± SD) of 1.16 ± 0.36 nM was observed at 8 hrs with a serum half-life of 36 hrs. In conclusion, a PTH fusion molecule with GHBP showed bioactivity and delayed clearance. The reduced bioactivity of Fusion-2 compared to PTH and Fusion-1 is compatible with our hypothesis that there is intra-molecular binding to the extracellular domain of the PTH receptor which may result in a store of bioactivity and may explain the greater maximal fold induction in the bioassay despite a reduced EC50. The published serum half-life of PTH 1-34 in rats is 59 minutes1 and so Fusion-1 had greatly delayed clearance. These results validate the approach of generating a long-acting PTH through protein fusion with GHBP. 1. Kostenuik, PJ et al. Journal of Bone and Mineral Research, Volume 22, Number 10, 2007 Sources of Research Support: MRC P2D

SAT-211 Gonadotrophin Rise Following Kisspeptin Analogue (MVT-602) Is Increased In Women With Hypothalamic Amenorrhoea Compared To Healthy Women

Background Hypothalamic amenorrhoea (HA) is a condition characterised by reduced GnRH pulsatility as a result of low body weight, excessive exercise, or psychological stress. HA leads to anovulatory infertility and osteoporosis. Kisspeptin is a neuropeptide that is known to be a key regulator of hypothalamic GnRH function. Hypothalamic kisspeptin expression is reduced, and kisspeptin receptor expression increased, in a rodent model of HA. We have previously demonstrated that a continuous infusion of the native form of kisspeptin (kisspeptin-54; KP54) can restore GnRH pulsatility in women with HA, but excessive doses cause tachyphylaxis. Kisspeptin analogue (MVT-602) is a modified form of kisspeptin with a longer half-life compared to native kisspeptin-54 (1.5-2.2h vs 0.5h). Importantly, the more prolonged gonadotrophin profile induced by MVT-602 could enable restoration of physiological hormonal secretion with less frequent administration than by KP54, and thus mitigate against the risk of tachyphylaxis. We therefore investigated the hormonal response to MVT-602 in women with HA to evaluate its potential future utility in the treatment of anovulatory infertility. Methods A previous dose-finding study during the follicular phase of healthy women determined that no further increase in gonadotrophin rise was observed at doses of MVT-602 higher than 0.03nmol/kg. We therefore compared the gonadotrophin rise following a subcutaneous bolus of MVT-602 at a dose of 0.03nmol/kg in 6 women with HA compared to 9 healthy women studied during the follicular phase of their menstrual cycle (day 1-4). Serum gonadotrophin and oestradiol levels were monitored every 30mins for 24hrs. Groups were compared by unpaired t test. Results The maximal rise in LH following MVT-602, was over two-fold greater in women with HA compared to healthy women in the follicular phase (mean±SD of maximal change in LH: HA 18.3±11.0iU/L, follicular phase 7.4±2.7iU/L; P=0.01). The time to peak LH was expedited in women with HA (time to first peak: HA 380±53mins, follicular phase 1067±415mins; P=0.002). Serum FSH rise was also augmented by over four-fold in women with HA (mean±SD of maximal change in FSH: HA 10.0±4.4iU/L, follicular phase 2.2±1.6iU/L; P=0.0003). Maximal rise in oestradiol was higher in women with HA (700pmol/L) when compared with healthy women (297pmol/L; P=0.03). Conclusion In women with HA, the rise in gonadotrophins following MVT-602 is more pronounced and occurs sooner than in healthy women during the follicular phase. The augmented and sustained rise in oestradiol highlights the potential for MVT-602 to be used as an ovulation induction agent in women with anovulatory HA. Therefore, further research is indicated to evaluate repeated administration of MVT-602 as a novel therapeutic approach to restore fertility in HA.

OR33-4 A Single Subcutaneous Injection Of The Kisspeptin Analogue, MVT-602, Induces A More Prolonged LH Surge Compared With Kisspeptin-54 In Healthy Women

Background Kisspeptin is a hypothalamic neuropeptide that is requisite for normal reproductive health. A subcutaneous bolus of the native form of kisspeptin (kisspeptin-54; KP54) induces an LH-surge lasting 12-14hrs, to safely mature oocytes during in vitro fertilisation (IVF) treatment. The kisspeptin analogue, MVT-602, has a longer half-life (t1/2 1.5-2.2h) than native KP54 (t1/2 0.5h), which could therefore confer significant advantages as an oocyte maturation trigger in the treatment of infertility. Whilst MVT-602 has been shown to stimulate LH release in men, its effects in women have not previously been investigated. To address this, we studied the effect of MVT-602 on gonadotrophin release in healthy women for the first time. Methods A two-phase dose-finding study was undertaken during the early follicular phase (Day 1-4) of 12 healthy women aged 18-35yrs with regular menstrual cycles. During phase 1, a broad dose-range for MVT-602 was determined: three women received a single subcutaneous bolus of one of five doses of MVT-602 (0.003, 0.03, 0.1, 0.3, or 1.0nmol/kg) in successive menstrual cycles. Reproductive hormones were measured every 30min for 14hrs post-MVT-602, and again at 24hrs and 48hrs post-injection. During phase 2, an additional 9 women received either KP54 (9.6nmol/kg), or MVT-602 at doses of 0.01 or 0.03nmol/kg during the follicular phase of successive menstrual cycles, following which reproductive hormone levels were monitored every 30mins for 24hrs post-injection. Intervention groups were compared by one-way ANOVA with post hoc Tukey’s test. ResultsPhase 1: Peak serum LH levels occurred between 14-24hrs and no further increases occurred with MVT-602 at doses greater than 0.03 nmol/kg. Phase 2: Peak amplitude of serum LH was found to be similar following KP54 and MVT-602 (mean±SD of peak LH KP54 12.3 ±5.3iU/L; MVT-602 0.01nmol/kg 11.4 ±4.2iU/L; MVT-602 0.03nmol/kg 11.1 ±3.0iU/L, p>0.05). However, time to peak LH was later following MVT-602 (22hrs) when compared with KP54 (4.9hrs; P<0.0001). Thus, the area under the curve (AUC) for LH exposure was significantly increased following MVT-602 when compared with KP54 (mean±SD of AUC LH KP54 9,095 ±5,632iU.min/L; MVT-602 0.01nmol/kg 18,129 ±6,471iU.min/L, P=0.02 vs KP54; MVT-602 0.03nmol/kg 20,086 ±6,227iU.min/L, P=0.004 vs KP54). Conclusion A single subcutaneous bolus of MVT-602 in healthy women resulted in an LH surge of similar amplitude, but of longer duration than by KP54. During studies evaluating the utility of KP54 as a trigger of oocyte maturation in IVF treatment, extending the duration of LH surge with a second bolus of KP54 safely optimised oocyte maturation. Thus, the prolonged gonadotrophin surge induced by MVT-602 could be of significant utility not only to safely optimise oocyte maturation in IVF treatment, but also to treat other reproductive disorders affecting women’s health.

Insulin Resistance and Portal Vein Thrombosis.

A 76-year-old man with dyslipidemia, hypertension, and type 2 diabetes complicated by coronary artery disease and stage 3 chronic kidney disease was admitted to the hospital with diabetic ketoacidosis (DKA) after a respiratory infection that was treated with antibiotics and glucocorticoids 1 month before admission. His medical history included a motor vehicle accident with perforation of the colon, hemi-resection 6 years ago; bladder polyp, resection 5 years ago; and possible bladder cancer, more than 30 years ago. He had no personal or family history of thrombosis. The patient was diagnosed with diabetes in 2001 and was most recently treated with metformin and sitagliptin. His A1C was maintained at ∼7% until 3 years before admission. However, 3 months before admission, his A1C was 10.5%, with no data on glycemic control in the interim 3 years. He has never smoked, but has a history of heavy alcohol consumption, which he says he stopped 50 years ago. On examination several days after admission, he had a BMI of 27.5 kg/m2 with central obesity, stable vital signs, clear lung fields, and a benign abdomen. At admission, he was found to have hyperglycemia with mild anion gap acidosis and elevated beta-hydroxybutyrate. He also had leukocytosis with acute kidney injury (Table 1). The patient’s DKA resolved promptly with intravenous (IV) insulin and fluids (Figure 1). He was transitioned to subcutaneous insulin after 24 hours. Despite increasing doses of subcutaneous basal and bolus insulin, his blood glucose remained >300 mg/dL, ultimately requiring resumption of IV insulin with a requirement of 2–5 units/hour, even when fasting. View this table: TABLE 1. Admission Laboratory Values FIGURE 1. Management of DKA with IV insulin during first 24 hours after admission. The patient presented with DKA, which was managed with IV insulin using the DKA Endotool software protocol (Monarch Medical Technologies, Charlotte, N.C.). Anion gap was closed …

Reversal of cerebrovascular constriction in experimental cerebral malaria by L-arginine

Vascular dysfunction associated with low nitric oxide (NO) biavailability and low plasma L-arginine levels is observed in both human and experimental cerebral malaria (ECM). In ECM, cerebrovascular constriction results in decreased pial blood flow and hypoxia, and administration of NO donors reverses constriction and increases survival. Supplementation of L-arginine, the substrate for NO synthesis by NO synthases, has been considered as a strategy to improve vascular health and act as adjunctive therapy in human severe malaria. We investigated the effect of L-arginine supplementation on pial vascular tonus of mice with ECM after direct superfusion on the brain surface or systemic delivery. Pial arteriolar diameters of Plasmodium berghei-infected mice with implanted cranial windows were measured using intravital microscopy methods, before and after L-arginine administration. Systemic delivery of L-arginine was performed intravenously, at 10, 50, 100 and 200 mg/kg, as bolus injection or slowly through osmotic pumps, combined or not with artesunate. Direct superfusion of L-arginine (10−7M, 10−5M and 10−3M) on the brain surface of mice with ECM resulted in immediate, consistent and dose-dependent dilation of pial arterioles. ECM mice showed marked cerebrovascular constriction that progressively worsened over a 24 h-period after subcutaneous saline bolus administration. L-arginine administration prevented the worsening in pial constriction at all the doses tested, and at 50 mg/kg and 100 mg/kg it induced temporary reversal of vasoconstriction. Slow, continuous delivery of L-arginine by osmotic pumps, or combined bolus administration of artesunate with L-arginine, also prevented worsening of pial constriction and resulted in improved survival of mice with ECM. L-arginine ameliorates pial vasoconstriction in mice with ECM.

Subcutaneous Anti-D versus intravenous methylprednisolone for the treatment of immune thrombocytopenic purpura

Background: Established treatment option for immune thrombocytopenic purpura (ITP) are intravenous immunoglobulin (IVIg), anti-D immunoglobulin’ and high dose intravenous methyl prednisolone (HIVMP). The present study was undertaken to compare the efficacy of subcutaneous bolus anti-D over HIVMP in the treatment of ITP.Methods: A randomized clinical trial was conducted on a total 20 children with ITP, presented with extensive bleeding manifestation and platelet count &lt;20 × 109/L;10 children received single dose subcutaneous anti-D (75 microgram/kg) and 10 children received HIVMP (30 mg/kg/dose) for 3 consecutive days. Patients were monitored for response to treatment and adverse events, platelet count and hemoglobin label were done in all patients at 24-hour, 48-hour, 72 hour, 1st week, 2nd week, 1st month, 2nd month and 3rd month after treatment to observe the change. Response rate define as a platelet count over 20 × 109/L within 72 hours of treatment. All the data were analyzed with the help of SPSS software version 16.0.Results: By 24 hours of treatment 40% patient of anti-D and 10% patients of HIVMP group had platelet count &gt;20 x109/L, by 72 hours 90% patients of both group achieved complete response (P =1.750). In HIVMP group the rate of remission gradually decreasing but in anti-D group it was persistently remain high. In anti-D group hemoglobin concentration decreased in 80% cases (P=0.023) but rate of decrease was not significant. New hemorrhage or significant extension of hemorrhage did not observe in any group.Conclusions: A single dose of subcutaneous anti-D raised platelet count in children with ITP more rapidly and effectively than HIVMP (30 mg/kg/dose) with an acceptable safety profile.

User- and Health Care Provider–Reported Outcomes for a Wearable Bolus Insulin Delivery Patch

User- and Health Care Provider–Reported Outcomes for a Wearable Bolus Insulin Delivery Patch

Optimizing Basal-Bolus Therapy in T2D—A Randomized Controlled Trial Comparing Bolus Insulin Delivery Using an Insulin Patch vs. an Insulin Pen

Optimizing Basal-Bolus Therapy in T2D—A Randomized Controlled Trial Comparing Bolus Insulin Delivery Using an Insulin Patch vs. an Insulin Pen

Characterization of SNF472 pharmacokinetics and efficacy in uremic and non-uremic rats models of cardiovascular calcification

End-stage renal disease is strongly associated with progressive cardiovascular calcification (CVC) and there is currently no therapy targeted to treat CVC. SNF472 is an experimental formulation under development for treatment of soft tissue calcification. We have investigated the pharmacokinetics of SNF472 administration in rats and its inhibitory effects on CVC. SNF472 was studied in three rat models: (1) prevention of vitamin D3-induced CVC with an intravenous SNF472 bolus of 1 mg/kg SNF472, (2) inhibition of progression of vitamin D3-induced CVC with a subcutaneous SNF472 bolus of 10 or 60 mg/kg SNF472, starting after calcification induction, (3) CVC in adenine-induced uremic rats treated with 50 mg/kg SNF472 via i.v. 4h -infusion. Uremic rats presented lower plasma levels of SNF472 than control animals after i.v. infusion. CVC in non-uremic rats was inhibited by 60–70% after treatment with SNF472 and progression of cardiac calcification completely blocked. Development of CVC in uremic rats was inhibited by up to 80% following i.v. infusion of SNF472. SNF472 inhibits the development and progression of CVC in uremic and non-uremic rats in the same range of SNF472 plasma levels but using in each case the required dose to obtain those levels. These results collectively support the development of SNF472 as a novel therapeutic option for treatment of CVC in humans.

A Novel Porcine Model for Future Studies of Cell-enriched Fat Grafting.

Cell-enriched fat grafting has shown promising results for improving graft survival, although many questions remain unanswered. A large animal model is crucial for bridging the gap between rodent studies and human trials. We present a step-by-step approach in using the Göttingen minipig as a model for future studies of cell-enriched large volume fat grafting. Fat grafting was performed as bolus injections and structural fat grafting. Graft retention was assessed by magnetic resonance imaging after 120 days. The stromal vascular fraction (SVF) was isolated from excised fat and liposuctioned fat from different anatomical sites and analyzed. Porcine adipose-derived stem/stromal cells (ASCs) were cultured in different growth supplements, and population doubling time, maximum cell yield, expression of surface markers, and differentiation potential were investigated. Structural fat grafting in the breast and subcutaneous bolus grafting in the abdomen revealed average graft retention of 53.55% and 15.28%, respectively, which are similar to human reports. Liposuction yielded fewer SVF cells than fat excision, and abdominal fat had the most SVF cells/g fat with SVF yields similar to humans. Additionally, we demonstrated that porcine ASCs can be readily isolated and expanded in culture in allogeneic porcine platelet lysate and fetal bovine serum and that the use of 10% porcine platelet lysate or 20% fetal bovine serum resulted in population doubling time, maximum cell yield, surface marker profile, and trilineage differentiation that were comparable with humans. The Göttingen minipig is a feasible and cost-effective, large animal model for future translational studies of cell-enriched fat grafting.

Alternative Administration Routes of a Biopolymer‐Stabilized VEGF Chimera to Optimize Therapeutic Efficacy in Treating a Rodent Model of Placental Ischemia

Preeclampsia is a form of gestational hypertension that complicates 5–8% of pregnancies in the United States. The unknown etiology originates from abnormal remodeling of the maternal spiral arteries, creating an ischemic placenta that releases factors that drive the pathophysiology. One of these pathogenic factors, soluble fms‐like tyrosine kinase‐1 (sFlt‐1), causes angiogenic imbalance by sequestering vascular endothelial growth factor (VEGF), leading to endothelial dysfunction and hypertension. Apart from delivery of the ischemic placenta, no effective therapy exists to treat preeclampsia. Innovative treatments are needed not only to reduce the morbidity and mortality rates during the preeclamptic index pregnancy, but also to decrease the incidence of later life cardiovascular‐renal and metabolic risk factors that are associated with the systemic endothelial dysfunction.In order to develop treatments that are safe for both the mother and fetus, we are testing novel therapies that target sFlt‐1 and other pathogenic factors in a preclinical model of placental ischemia, the reduced uterine perfusion pressure (RUPP) surgery. Previously, we demonstrated in timed pregnant Sprague‐Dawley rats that the biopolymer drug carrier elastin‐like polypeptide (ELP) fused to human VEGF‐A121 (ELP‐VEGF) prevents VEGF from crossing the placental barrier and thus ameliorates the risk of fetal exposure. Furthermore, in pregnant rats that had undergone the RUPP surgery, chronic administration of ELP‐VEGF at 5 mg/kg/day via intraperitoneal minipump blocked hypertension, significantly enhanced renal nitric oxide signaling, and had no deleterious effect on fetal weight or placental efficiency. However, dams also experienced dose‐dependent adverse events likely attributed to the continuous intraperitoneal infusion method, including ascites production, neovascular tissue encapsulation around the minipump, and, at the 10 mg/kg/day dose, fetal loss.With the aim of minimizing dose‐dependent side effects while retaining the therapeutic efficacy of ELP‐VEGF, chronic biodistribution studies were conducted in non‐pregnant female hairless Sprague‐Dawley rats. ELP‐VEGF was fluorescently labeled with Alexa Fluor 633 succinimidyl ester. In a repeated intravenous dosing cohort, a 5 mg/kg IV bolus of fluorescent labeled ELP‐VEGF was delivered via jugular catheter once daily for 5 days. In a parallel controlled‐release dosing study, rats received a single 5 mg/kg bolus subcutaneously between the scapulae. In vivo imaging and blood draws were conducted at specific time points in order to assess ELP‐VEGF biodistribution and plasma clearance rates, respectively. Mean fluorescence radiant efficiency was averaged, levels were corrected for autofluorescence, and data were fit to the standard curve of the injected protein. We report that whereas a single subcutaneous bolus yields a slow absorption and release of ELP‐VEGF, repeated intravenous dosing can replicate tissue levels comparable to the therapeutic levels achieved by the intraperitoneal osmotic pumps, and free of any peritoneal ascites. Plasma clearance rates and terminal half‐life of ELP‐VEGF determined from these studies are being employed in ongoing experiments to test the therapeutic efficacy of these administration routes in the RUPP model of placental ischemia.Support or Funding InformationSupported by NIH NHLBI grant R01HL121527 (GLB), NIH grant T32HL105324 (OCL) and AHA fellowship 17POST3346012 (OCL).This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Effects of Preceding Ethanol Intake on Glucose Response to Low-Dose Glucagon in Individuals With Type 1 Diabetes: A Randomized, Placebo-Controlled, Crossover Study.

This study investigated whether preceding ethanol intake impairs glucose response to low-dose glucagon in individuals with type 1 diabetes. This was a randomized, crossover, placebo-controlled study in 12 insulin pump-treated individuals (median [interquartile range] age, 37 [31-51] years; HbA1c, 57 [51-59] mmol/mol or 7.3% [6.8-7.5]; and BMI, 23.9 [22-25] kg/m2). During two overnight study visits, a 6 p.m. dinner (1 g carbohydrates/kg) was served with diet drink (placebo) or diet drink and ethanol (0.8 g/kg). After 8-9 h, ethanol was estimated to be metabolized, and a subcutaneous (s.c.) insulin bolus was given to induce mild hypoglycemia. When plasma glucose (PG) was ≤3.9 mmol/L, 100 µg glucagon was given s.c., followed by another s.c. 100 µg glucagon 2 h later. Primary end point was incremental peak PG induced by the first glucagon bolus. Ethanol was undetectable before insulin administration at both visits. The insulin doses (mean ± SEM: 2.5 ± 0.4 vs. 2.7 ± 0.4 IU) to induce hypoglycemia (3.7 ± 0.1 vs. 3.9 ± 0.1 mmol/L) did not differ and caused similar insulin levels (28.3 ± 4.6 vs. 26.1 ± 4.0 mU/L) before glucagon administration on ethanol and placebo visits (all, P > 0.05). The first glucagon bolus tended to cause lower incremental peak PG (2.0 ± 0.5 vs. 2.9 ± 0.3 mmol/L, P = 0.06), lower incremental area under the curve (87 ± 40 vs. 191 ± 37 mmol/L × min, P = 0.08), and lower 2-h PG level (3.6 ± 1.0 vs. 4.8 ± 0.4 mmol/L, P = 0.05) after ethanol compared with placebo. The second glucagon bolus had similar responses between visits, but PG remained 1.8 ± 0.7 mmol/L lower after ethanol compared with placebo. The ability of low-dose glucagon to treat mild hypoglycemia persisted with preceding ethanol intake, although it tended to be attenuated.

Plasma anti-FXa concentration after continuous intravenous infusion and subcutaneous dosing of enoxaparin for thromboprophylaxis in critically ill patients. A randomized clinical trial

IntroductionIn intensive care unit (ICU) patients, subcutaneous low-molecular weight heparin thromboprophylaxis results in lower plasma anti-factor Xa (anti-FXa) levels compared to general ward patients. The aim of this study was to examine whether enoxaparin thromboprophylaxis given as a continuous intravenous infusion (CII) results in more constant and predictable anti-FXa concentration than standard subcutaneous bolus (SCB) administration. Materials and methodsThis was a prospective, single-blind, multicenter, randomized controlled trial where ICU patients requiring thromboprophylaxis received enoxaparin either 40mg as a SCB once daily or 40mg as a CII over 24h for three consecutive days.The primary outcome was maximum serum anti-FXa concentration (Cmax24h) within the first 24h; the secondary outcome was anti-FXa area under the curve (AUC)(0–24h). Trough level was measured at 72h. ResultsThirty-nine patients were included in the intention to treat analysis. The median anti-FXa Cmax24h was 0.05 (interquartile range, IQR, 0.05–0.18) IU/ml in the CII group and 0.18 (IQR, 0.12–0.33) IU/ml in the SCB group (p=0.05). Median anti-FXa AUC(0–24h) was 1.20 (IQR, 0.98–2.88) in the CII and 1.54 (IQR, 1.22–4.12) in the SCB group (p=0.095). After 72h, 66.7% of patients in the CII group had a detectable anti-FXa concentration of >0.1IU/ml, compared with 16.7% in the SCB group (p=0.019). ConclusionsContinuous infusion of enoxaparin led to lower anti-FXa Cmax24h than standard SCB administration. No difference in anti-FXa AUC0–24h was detected.

Mechanism-Based Pharmacokinetic/Pharmacodynamic Modeling of the Glucagon-Like Peptide-1 Receptor Agonist Exenatide to Characterize Its Antiobesity Effects in Diet-Induced Obese Mice.

In addition to their potent antidiabetic effects, glucagon-like peptide-1 (GLP-1) analogs lower body weight in humans. Hence, agonistic targeting of the GLP-1 receptor could be a valid approach to target obesity. However, quantitative analyses of the pharmacokinetic/pharmacodynamic (PK/PD) relationship between GLP-1 analogs and their antiobesity effect have not been reported in either animals or humans. Therefore, the present study was performed to establish a mechanism-based PK/PD model of GLP-1 receptor agonists using the GLP-1 analog exenatide for the development of promising new antiobesity drugs. Exenatide was administered to high-fat diet-induced obese C57BL/6J mice via subcutaneous bolus and continuous infusion. Food intake and body-weight reductions were observed and depended on the plasma concentrations of exenatide. The homeostatic feedback model, in which food intake is assumed to be regulated by appetite control signals, described the relationship among the plasma concentration-time profile of exenatide, food intake, and body weight. The estimated IC50 of exenatide against food intake was 2.05 pM, which is similar to the reported KD value of exenatide in rat brain and the estimated EC50 value for augmentation of insulin secretion in humans. The PK/PD model simulation indicated that subcutaneous infusion would show a stronger effect on body-weight reduction than bolus dosing would. This novel, quantitative PK/PD model could be used for antiobesity research and development of GLP-1 analogs, GLP-1 secretagogues, GLP-1 degradation inhibitors, and combinations thereof by allowing the estimation of appropriate pharmacokinetic profiles and dosing regimens.

Insulin Bolus Calculator in a Pediatric Hospital. Safety and User Perceptions.

Insulin dosing in hospitalized pediatric patients is challenging and requires dosing to be matched with the specific clinical and nutritional circumstances. We implemented a customized subcutaneous insulin bolus dose calculator tool integrated with the electronic health record to improve patient care. Here we describe this tool, its utilization and safety, and assess user satisfaction and perceptions of the tool. Blood glucose results for all patients who received insulin with and without the calculator tool were compared to assess safety. To assess user perceptions and satisfaction, a survey was sent to all identified users who interacted with the tool during the period from May 2015 to the end of November 2015. Survey responses were summarized, mean user satisfaction calculated, and correlation of Likert scale items with overall satisfaction assessed. Hypoglycemia rates (2.2% and 2.9%, p = 0.17) and severe hypoglycemia rates (0.04% and 0.1%, p = 0.21) were similar for the groups that received insulin with and without the calculator tool. Overall satisfaction for all survey respondents was high (4.05, SD = 0.83). Physicians indicated a slightly higher satisfaction than nurses (4.33 versus 3.94, p = 0.04). User agreement with improvement of quality of care showed the highest correlation with overall satisfaction (r = 0.80, 95% CI 0.7 - 0.87). Implementation of an insulin calculator tool streamlined ordering and administration of insulin in a pediatric academic institution while maintaining patient safety. Users indicated high overall satisfaction with the tool.

Cross-Validation of a Glucose-Insulin-Glucagon Pharmacodynamics Model for Simulation Using Data From Patients With Type 1 Diabetes.

Currently, no consensus exists on a model describing endogenous glucose production (EGP) as a function of glucagon concentrations. Reliable simulations to determine the glucagon dose preventing or treating hypoglycemia or to tune a dual-hormone artificial pancreas control algorithm need a validated glucoregulatory model including the effect of glucagon. Eight type 1 diabetes (T1D) patients each received a subcutaneous (SC) bolus of insulin on four study days to induce mild hypoglycemia followed by a SC bolus of saline or 100, 200, or 300 µg of glucagon. Blood samples were analyzed for concentrations of glucagon, insulin, and glucose. We fitted pharmacokinetic (PK) models to insulin and glucagon data using maximum likelihood and maximum a posteriori estimation methods. Similarly, we fitted a pharmacodynamic (PD) model to glucose data. The PD model included multiplicative effects of insulin and glucagon on EGP. Bias and precision of PD model test fits were assessed by mean predictive error (MPE) and mean absolute predictive error (MAPE). Assuming constant variables in a subject across nonoutlier visits and using thresholds of ±15% MPE and 20% MAPE, we accepted at least one and at most three PD model test fits in each of the seven subjects. Thus, we successfully validated the PD model by leave-one-out cross-validation in seven out of eight T1D patients. The PD model accurately simulates glucose excursions based on plasma insulin and glucagon concentrations. The reported PK/PD model including equations and fitted parameters allows for in silico experiments that may help improve diabetes treatment involving glucagon for prevention of hypoglycemia.