Twice-daily Subcutaneous Injections Research Articles

Chronic exposure to incretin metabolites GLP-1(9−36) and GIP(3−42) affect islet morphology and beta cell health in high fat fed mice

The incretin hormones, glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), are rapidly degraded by dipeptidyl peptidase-4 (DPP-4) to their major circulating metabolites GLP-1(9−36) and GIP(3−42). This study investigates the possible effects of these metabolites, and the equivalent exendin molecule Ex(9−39), on pancreatic islet morphology and constituent alpha and beta cells in high-fat diet (HFD) fed mice. Male Swiss TO-mice (6–8 weeks-old) were maintained on a HFD or normal diet (ND) for 4 months and then received twice-daily subcutaneous injections of GLP-1(9−36), GIP(3−42), Ex(9−39) (25 nmol/kg bw) or saline vehicle (0.9% (w/v) NaCl) over a 60-day period. Metabolic parameters were monitored and excised pancreatic tissues were used for immunohistochemical analysis. Body weight and assessed metabolic indices were not changed by peptide administration. GLP-1(9−36) significantly (p<0.001) increased islet density per mm2 tissue, that was decreased (p<0.05) by HFD. Islet, beta and alpha cell areas were increased (p<0.01) following HFD and subsequently reduced (p<0.01-p<0.001) by GIP(3−42) and Ex(9−39) treatment. While GLP-1(9−36) did not affect islet and beta cell areas in HFD mice, it significantly (p<0.01) decreased alpha cell area. Compared to ND and HFD mice, GIP(3−42) treatment significantly (p<0.05) increased beta cell proliferation. Whilst HFD increased (p<0.001) beta cell apoptosis, this was reduced (p<0.01-p<0.001) by both GLP-1(9−36) and GIP(3−42). These data indicate that the major circulating forms of GLP-1 and GIP, namely GLP-1(9−36) and GIP(3−42) previously considered largely inactive, may directly impact pancreatic morphology, with an important protective effect on beta cell health under conditions of beta cell stress.

Relief of Morphine Withdrawal Symptoms by Japanese Sake Yeast Supplement (Saccharomyces cerevisiae sake) Through Adenosine A1 Receptor Activation in Mice

Background: Morphine withdrawal syndrome is often treated with chemical drugs; however, these drugs can have concerning side effects. Some natural substances might offer safer alternatives for managing withdrawal symptoms. The neuroprotective activity of the adenosine A1 receptor (A1R) in the central nervous system (CNS) has been mentioned before. As a novel natural agent, Japanese sake yeast is enriched with adenosine analogs. Objectives: As the first report, the present study was designed to evaluate the effects of the Japanese sake yeast supplement against the excitatory signs of morphine withdrawal syndrome in mice. Methods: Mice were treated orally (gavage) with sake yeast at doses of 100, 200, and 300 mg kg-1 once daily for a week. Furthermore, during the last 3 days of receiving sake yeast, the animals were made physically dependent on morphine by being given twice-daily subcutaneous injections of increasing doses of morphine (30 - 90 mg/kg) for 3 consecutive days. The withdrawal syndrome was induced in animals through the intraperitoneal (i.p.) administration of naloxone (3 mg kg-1) or was elicited spontaneously. After the examination of withdrawal signs, the animals were decapitated, and their brains were prepared for histopathology. Results: Sake yeast alleviated the intensity of ptosis, piloerection, diarrhea, irritability, and tremor during the two withdrawal syndrome protocols (P

Cardiorespiratory anomalies and increased brainstem microglia in a rat model of neonatal opioid withdrawal syndrome

Infants born with neonatal opioid withdrawal syndrome (NOWS) can display abnormal cardiorespiratory patterns including tachypnea, tachycardia, and impaired ventilatory responses to hypoxia (HVR) and hypercapnia (HCVR). Chronic morphine exposure is associated with increased midbrain microglial expression. Using a rat model of pre- and post-natal morphine exposure, we assessed cardiorespiratory features of NOWS (resting tachycardia and tachypnea) including the attenuated HVR and HCVR and whether they are associated with increased brainstem microglia expression. Pregnant rats (dams) received twice-daily subcutaneous injections of morphine (5 mg/kg) during the third (last) week of pregnancy to simulate 3rd trimester in utero opioid exposure. Offspring then received once-daily subcutaneous injections of morphine (0.5 mg/kg) until postnatal (P) day P10 days of age to simulate postnatal morphine therapy. Cardiorespiratory responses were assessed 24 h later (P11 days) following spontaneous withdrawal. Compared to saline-treated pups, morphine-exposed offspring exhibited tachycardia and tachypnea as well as an attenuated HVR and HCVR. Microglial cell counts were increased in the nucleus tractus solitarius (nTS), dorsal motor nucleus of the vagus (DMNV) and nucleus ambiguous (NAamb), but not the retrapezoid nucleus (RTN) or the non-cardiorespriatory region, the cuneate nucleus (CN). These data suggest that the cardiorespiratory features and autonomic dysregulation in NOWS infants may be associated with altered microglial function in specific brainstem cardiorespiratory control regions.

Increased brainstem microglia is associated with an attenuated hypercarbic ventilatory response in a rat model of neonatal opioid withdrawal syndrome

Background Infants born with neonatal opioid withdrawal syndrome (NOWS) display abnormal respiratory patterns including tachypnea, apnea and impaired ventilatory responses to hypoxia and hypercarbia challenges. Infants with NOWS are also at an increased risk of sudden infant death syndrome (SIDS), which is associated with impairments in respiratory control and increased gliosis in key brainstem respiratory control regions including the nucleus tractus solitarius (nTS). Objective Use a rat model of neonatal opioid withdrawal syndrome to assess whether pre- and postnatal morphine exposure attenuates the ventilatory responses to hypoxia and hypercarbia challenges in the offspring and whether they are associated with increased nTS microglia expression. Design/Methods Pregnant female rats (dams) received twice-daily subcutaneous injections of morphine (5mg/kg) during the third (last) week of pregnancy to simulate 3rd trimester in utero opioid exposure. After birth, the pups received once-daily subcutaneous injections of morphine (1mg/kg), through postnatal day 10 to simulate postnatal morphine therapy. Whole-body plethysmography was used precisely 24 hours later to assess ventilatory defense responses to acute hypoxia (HVR) and hypercapnia (HCVR) challenge (5 minutes at 10% O2 and 5% CO2, respectively). Brainstems were removed to assess nTS microglia expression using immunohistochemistry and a glial (Iba-1) marker. Results Compared to saline-treated pups, morphine exposure attenuated the HCVR, but not the HVR (Fig. 1A). Morphine-exposed offspring also expressed increased number of microglia in the nTS (Fig. 1B). Conclusion The disturbances in neonatal hypercarbia challenge are associated with increased brainstem microglia expression, which could contribute to the etiology underlying the increased risk of SIDS in infants with NOWS.

Liposomal Grb2 antisense oligodeoxynucleotide (BP1001) in patients with refractory or relapsed haematological malignancies: a single-centre, open-label, dose-escalation, phase 1/1b trial

Activating mutations of tyrosine kinases are common in leukaemias. Oncogenic tyrosine kinases use the growth factor receptor-bound protein 2 (Grb2) for signal transduction, leading to activation of mitogen-activated protein kinase (MAPK) 1 and MAPK3 (ERK2 and ERK1). We hypothesised that inhibition of Grb2 would suppress ERK1 and ERK2 activation and inhibit leukaemia progression. To inhibit Grb2, a liposome-incorporated antisense oligodeoxynucleotide that blocks Grb2 protein expression, BP1001, was developed. We report the first phase 1 findings of BP1001. In this single-centre, open-label, dose-escalation phase 1/1b trial, we enrolled participants (aged ≥18 years) with refractory or relapsed acute myeloid leukaemia, Philadelphia-chromosome-positive chronic myeloid leukaemia (in chronic, accelerated, or blast phase), acute lymphoblastic leukaemia, or myelodysplastic syndrome, at MD Anderson Cancer Center (Houston, TX, USA). We used a 3 + 3 dose escalation strategy, with at least three patients enrolled at each dose level. We administered BP1001 intravenously, twice weekly, for 28 days, with a starting dose of 5 mg/m2. If two or more patients developed toxic effects of grade 3 or higher, that dose level was deemed toxic. The dose was escalated if it did not produce dose-limiting toxic effects, and patients would be sequentially enrolled into cohort 2 (10 mg/m2), cohort 3 (20 mg/m2), cohort 4 (40 mg/m2), cohort 5 (60 mg/m2), or cohort 6 (90 mg/m2). After completion of monotherapy, we assessed the safety and toxicity of BP1001 (60 or 90 mg/m2) in combination with 20 mg low-dose cytarabine (twice-daily subcutaneous injections) in a phase 1b study in patients with refractory or relapsed acute myeloid leukaemia (ie, those who were refractory to at least one previous therapy regimen and no more than one previous salvage regimen). The objectives of this study were to establish the toxicity and tolerance of escalating doses of BP1001 monotherapy in patients with refractory or relapsed leukaemia, to assess the maximum tolerated dose of BP1001, and to determine the optimal biologically active dose of BP1001, defined as a 50% reduction in Grb2 expression in circulating leukaemia cells. We also aimed to assess the in-vivo pharmacokinetics of BP1001 and tumour response. The study is completed and is registered with ClinicalTrials.gov, number NCT01159028. Between July 23, 2010, and Feb 23, 2016, we enrolled and treated 39 patients, of whom 27 were assessable for dose-limiting toxicity. The first patient treated had mucositis and hand-foot syndrome, which were assessed as possibly related to BP1001 and counted as a dose-limiting toxicity. We noted no other dose-limiting toxicities, and a maximum tolerated dose was not identified. The highest tested dose of BP1001 was 90 mg/m2. The most common grade 3-4 adverse events were cardiopulmonary disorders (25 [64%] of 39 patients), and fever (including neutropenic fever) and infections (17 [44%] patients). Grade 5 adverse events were cardiopulmonary disorders (two [5%] of 39 patients), fever (including neutropenic fever) and infections (two [5%] of 39 patients), and multi-organ failure (one [3%] of 39 patients). Nine (33%) of 27 patients who had peripheral blood blasts at the start of therapy had a reduction of 50% or more in peripheral blood blasts while receiving BP1001 montherapy. Three (10%) of 29 patients who had bone marrow blasts at the start of therapy had a reduction in bone marrow blasts of 50% or more while receiving BP1001 monotherapy. Per investigator's assessment, seven (22%) of 32 patients benefited from BP1001 monotherapy and had extended cycles of treatment. Of seven patients receiving BP1001 plus low-dose cytarabine combination therapy, two had complete remission, one had complete remission with incomplete haematological recovery, and two had stable disease with no dose-limiting toxicity; one patient died and one withdrew, both because of disease progression. There were eight deaths; none were treatment related. BP1001 is well tolerated, with early evidence of anti-leukaemic activity in combination with low-dose cytarabine. To further explore this anti-leukaemic activity, the efficacy of BP1001 plus low-dose cytarabine combination is being investigated in an ongoing phase 2 study in patients with previously untreated acute myeloid leukaemia who are ineligible for intensive induction therapy. Bio-Path Holdings Inc.

Unacylated Ghrelin Reduces Skeletal Muscle Reactive Oxygen Species Generation and Inflammation and Prevents High-Fat Diet-Induced Hyperglycemia and Whole-Body Insulin Resistance in Rodents.

Excess reactive oxygen species (ROS) generation and inflammation may contribute to obesity-associated skeletal muscle insulin resistance. Ghrelin is a gastric hormone whose unacylated form (UnAG) is associated with whole-body insulin sensitivity in humans and may reduce oxidative stress in nonmuscle cells in vitro. We hypothesized that UnAG 1) lowers muscle ROS production and inflammation and enhances tissue insulin action in lean rats and 2) prevents muscle metabolic alterations and normalizes insulin resistance and hyperglycemia in high-fat diet (HFD)-induced obesity. In 12-week-old lean rats, UnAG (4-day, twice-daily subcutaneous 200-µg injections) reduced gastrocnemius mitochondrial ROS generation and inflammatory cytokines while enhancing AKT-dependent signaling and insulin-stimulated glucose uptake. In HFD-treated mice, chronic UnAG overexpression prevented obesity-associated hyperglycemia and whole-body insulin resistance (insulin tolerance test) as well as muscle oxidative stress, inflammation, and altered insulin signaling. In myotubes, UnAG consistently lowered mitochondrial ROS production and enhanced insulin signaling, whereas UnAG effects were prevented by small interfering RNA-mediated silencing of the autophagy mediator ATG5. Thus, UnAG lowers mitochondrial ROS production and inflammation while enhancing insulin action in rodent skeletal muscle. In HFD-induced obesity, these effects prevent hyperglycemia and insulin resistance. Stimulated muscle autophagy could contribute to UnAG activities. These findings support UnAG as a therapeutic strategy for obesity-associated metabolic alterations.

Effects of Pump versus Twice-Daily Injection Delivery of Synthetic Parathyroid Hormone 1-34 in Children with Severe Congenital Hypoparathyroidism

To compare the response with synthetic human parathyroid hormone (PTH) 1-34 delivered by twice-daily injection vs insulin pump in children with severe congenital hypoparathyroidism due to calcium receptor mutation or autoimmune polyglandular syndrome type 1. Children and young adults aged 7-20 years with congenital hypoparathyroidism (N = 12) were randomized to receive PTH 1-34, delivered either by twice-daily subcutaneous injection or insulin pump for 13 weeks, followed by crossover to the opposite delivery method. The principal outcome measures were serum and urine calcium levels. Secondary outcomes included serum and urine magnesium and phosphate levels and bone turnover markers. PTH 1-34 delivered via pump produced near normalization of mean serum calcium (2.02 ± 0.05 [pump] vs 1.88 ± 0.03 [injection] mmol/L, P < .05, normal 2.05-2.5 mmol/L), normalized mean urine calcium excretion (5.17 ± 1.10 [pump] vs 6.67 ± 0.76 mmol/24 h/1.73 m(2), P = .3), and significantly reduced markers of bone turnover (P < .02). Serum and urine calcium and magnesium showed a biphasic pattern during twice-daily injection vs minimal fluctuation during pump delivery. The PTH 1-34 dosage was markedly reduced during pump delivery (0.32 ± 0.04 vs 0.85 ± 0.11 μg/kg/d, P < .001), and magnesium supplements were also reduced (P < .001). Compared with twice-daily delivery, pump delivery of PTH 1-34 provides more physiologic calcium homeostasis and bone turnover in children with severe congenital hypoparathyroidism.

The effects of kisspeptin administration on the menstrual cycle in healthy women

BackgroundKisspeptin (encoded by the KISS1 gene) is a crucial regulator of normal reproductive function. In human beings, KISS1 deletion results in a failure to go through puberty whereas activating mutations result in central precocious puberty. Administration of kisspeptin induces ovulation in rodents and sheep, but whether exogenous kisspeptin can alter the menstrual cycle in healthy women is not known. This study aimed to determine the effects of kisspeptin administration on the menstrual cycle in healthy women. MethodsA prospective, single-blinded, one-way crossover study at Imperial College, London, was performed. Five healthy female volunteers aged 24–37 years were recruited through adverts in the local press. They each received twice-daily subcutaneous injections of kisspeptin-54 or saline for 7 days during days 7 to 14 of their menstrual cycle. All women underwent serial assessments of basal reproductive hormones, ultrasound measurements, and luteinising hormone (LH) pulsatility, as well assessment of acute sensitivity to gonadotrophin-releasing hormone (GnRH) and kisspeptin injection. Because of the intensive protocol, women attended for assessments every 2–3 days throughout the cycle, rather than daily, to minimise stress and enhance compliance. Ethics approval was granted by the Hammersmith and Queen Charlotte's and Chelsea Hospitals Research Ethics Committee (registration number 05/Q0406/142). FindingsKisspeptin-54 treatment shortened the menstrual cycle (mean length of menstrual cycle: saline 28·6 days [SE 3·1] vs kisspeptin 26·8 [3·1], p=0·0043), advanced the onset of highest recorded serum LH (mean menstrual day of highest recorded LH 15·2 [SE 2·9] vs 13·0 [4·1], p=0·0372), and advanced the onset of the luteal phase of the menstrual cycle (mean menstrual day of progesterone increase 18·0 [SE 2·1] vs 15·8 [2·0], p=0·0402). On menstrual day 15, the largest ovarian follicle had a significantly higher diameter after kisspeptin-54 than after saline (mean diameter of largest follicle saline 10·0 mm [SE 4·4] vs kisspeptin 15·5 mm [2·2], p=0·04). LH pulsatility was maintained during kisspeptin-54 treatment. Sensitivity to exogenous kisspeptin-54 and exogenous GnRH was maintained during twice-daily kisspeptin-54 administration. InterpretationWe have shown, for the first time to our knowledge using biochemical and radiological data, that exogenous kisspeptin-54 advances the menstrual cycle in healthy women. These data have important therapeutic implications for the use of kisspeptin in the treatment of women with reproductive disorders. Even though participants attended every 2–3 days rather than daily, statistical significance in key parameters was still achieved, confirming the strength of the data. In addition, use of both biochemical and radiological data allowed detailed analysis of the underlying physiological processes. FundingWellcome Trust, National Institute for Health Research, UK Medical Research Council.

In Vitro Characterization of a Sustained-Release Formulation for Enfuvirtide

Although approved by the U.S. Food and Drug Administration, enfuvirtide is rarely used in combination antiretroviral therapies (cART) to treat HIV-1 infection, primarily because of its intense dosing schedule that requires twice-daily subcutaneous injection. Here, we describe the development of enfuvirtide-loaded, degradable poly(lactic-co-glycolic) acid microparticles that provide linear in vitro release of the drug over an 18-day period. This sustained-release formulation could make enfuvirtide more attractive for use in cART.

Twice-Daily Subcutaneous Injection of Kisspeptin-54 Does Not Abolish Menstrual Cyclicity in Healthy Female Volunteers

Background:Kisspeptin is a critical hypothalamic regulator of reproductive function. Chronic kisspeptin administration causes profound tachyphylaxis in male monkeys and in women with functional hypothalamic amenorrhea. The pharmacological effects of chronic kisspeptin exposure in healthy women with normal menstrual cycles have not been studied previously.Aim:Our aim was to determine the effects of follicular-phase kisspeptin-54 treatment on menstrual cyclicity in healthy women.Methods:We performed a prospective, single-blinded, 1-way crossover study. Healthy women received twice-daily sc injections of kisspeptin (6.4 nmol/kg) or 0.9% saline during menstrual days 7–14 (n = 5 per treatment arm). Serial assessments of basal reproductive hormones, ultrasound parameters, LH pulsatility, and acute sensitivity to GnRH and kisspeptin-54 injection were performed.Results:Menstrual cyclicity persisted in all women after follicular-phase kisspeptin-54 treatment. Chronic exposure to kisspeptin-54 did not abolish acute stimulation of LH after injection of kisspeptin-54 or GnRH. In addition, kisspeptin-54 treatment was associated with a shorter mean length of the menstrual cycle (mean length of menstrual cycle was 28.6 ± 1.4 days with saline vs 26.8 ± 3.1 days with kisspeptin, P < .01), earlier onset of highest recorded serum LH (mean menstrual day of highest LH was 15.2 ± 1.3 with saline vs 13.0 ± 1.9 with kisspeptin, P < .05), and earlier onset of the luteal phase (mean menstrual day of progesterone increase was 18.0 ± 2.1 with saline vs 15.8 ± 0.9 with kisspeptin, P < .05).Conclusion:Our data suggest that 1 week of exogenous kisspeptin-54 does not abolish menstrual cyclicity in healthy women. Further work is needed to determine whether kisspeptin could be used to treat certain anovulatory disorders.

Cardiac-derived adiponectin induced by long-term insulin treatment ameliorates myocardial ischemia/reperfusion injury in type 1 diabetic mice via AMPK signaling

Type 1 diabetes (T1DM) portends poor prognosis concerning ischemic heart disease. Adiponectin (APN), an adipocytokine possessing insulin sensitizing and metabolic regulatory effects, has been recognized as a potent cardioprotective molecule. However, the relationship between APN and T1DM remains controversial and the role of cardiac-derived APN in T1DM is unclear. This study is aimed to investigate the dynamic change of both plasma and cardiac-derived APN expressions in T1DM, and the particular role of cardiac-derived APN in T1DM against myocardial ischemia/reperfusion (MI/R) injury. T1DM was established via intraperitoneal injection of streptozocin and followed by twice-daily subcutaneous injection of insulin or vehicle for 14 days. Non-diabetic mice of wild type and APN knockout were subjected to insulin or vehicle injection. MI/R was induced in Langendorff-perfused hearts. Compared to non-diabetic mice, plasma APN levels of diabetic mice significantly increased at 7 days, and slightly decreased at 14 days, while cardiac-derived APN levels gradually decreased over time. The MI/R injury measured as infarct size and cardiomyocyte apoptosis nearly doubled in diabetic mice. 14 days of insulin treatment increased both plasma and cardiac-derived APN levels in diabetic mice and attenuated myocardial injury via increasing AMPK phosphorylation in T1DM, which was partly reversed by Compound C (an AMPK inhibitor). Moreover, APN deficiency aggravated MI/R injury and partly abolished the protective effect of insulin treatment against MI/R injury, which was associated with decreased AMPK phosphorylation. The results suggest that cardiac-derived APN stimulated by long-term insulin treatment in T1DM exerts cardioprotection against MI/R injury via myocardial AMPK activation.

The Incretin Axis in Cardiovascular Disease

In 1964, studies in just 2 subjects offered a simple, salient, and fundamental observation reported in 612 words: Glucose induces a greater insulin response when introduced through the gastrointestinal tract than when injected intravenously (the Figure, A).2 This finding built on studies dating to 1928 that injecting extracts of small intestine into animals lowered their glucose levels. Subsequently, this incretin effect was found to be mediated by glucagon-like peptide-1 (GLP1) and its action on pancreatic GLP1 receptors, in addition to contributions from glucose-dependent insulinotropic polypeptide.3,4 Moreover, the incretin response was found to be impaired in those with type 2 diabetes mellitus (T2D). We now know that the incretin axis also includes the enzyme dipeptidyl peptidase-IV (DPPIV), a serine protease that rapidly degrades GLP1 and other proteins.5 Ultimately, this arc of discovery led to new approved antidiabetic therapies: GLP1 analogs (exenatide, liraglutide) and DPPIV inhibitors (saxagliptin, sitagliptin, and, outside the United States, vildagliptin).4 For both classes of drugs, early preclinical experiments and smaller human studies suggest that targeting the incretin axis might address the elusive goal of an antidiabetic agent that improves cardiovascular disease.6,7 In the current issue of Circulation , Shah et al8 add this evolving story with their report that alogliptin, a DPPIV inhibitor in development, limits atherosclerosis and inflammation in 2 different mouse models. Given the increasing clinical use of approved incretin modulators, current large cardiovascular outcome trials with GLP1 agents and DPPIV inhibitors, and ongoing development of novel agents that target incretin signaling, further consideration of how the incretin axis might intersect the cardiovascular system is well warranted. Figure. A , The incretin effect. The well-documented phenomenon of oral glucose eliciting a higher insulin response than intravenous glucose at identical plasma levels of glucose is known as …

Impact on Health-Related Quality of Life of a Switch From Enfuvirtide to Raltegravir Among Multidrug-Resistant HIV-1–Infected Patients: A Randomized Open-Label Trial (EASIER-ANRS 138)

Background: Among multidrug-resistant HIV-1–infected patients, enfuvirtide has demonstrated sustained efficacy, but long-term use is inconvenient due to twice-daily subcutaneous injections which often induce injection-site reactions. We investigated whether a switch from enfuvirtide to raltegravir, an orally available HIV-integrase inhibitor, may improve health-related quality of life (HRQoL). Methods: 170 multidrug-resistant HIV–1–infected patients who were receiving enfuvirtide-based regimens were randomised to the maintenance of enfuvirtide or the switch to raltegravir at day 0. At week 24, all patients received raltegravir up to week 48. HRQoL was assessed at baseline and weeks 24 and 48 using a self-report MOS-HIV questionnaire. HRQoL scores were compared between arms using analysis of covariance (ANCOVA) models. Results: At week 24, least-squares means changes from baseline for the maintenance and the substitution arms were –5.3 and +5.8 (P = .001) for the pain score, –4.7 and +4.8 (P = .02) for the social functioning score, and –1.3 and +2.0 (P = .003) for the physical summary score, respectively. Conclusion: Among multidrug-resistant HIV-1–infected patients, a switch from enfuvirtide to raltegravir resulted in statistically significant improvements in multiple HRQoL dimensions over 24 weeks in comparison to the maintenance under enfuvirtide.

Efficacy of a new sustained-release microsphere formulation of exenatide, DA-3091, in Zucker diabetic fatty (ZDF) rats

Exenatide must be administered serially by twice-daily subcutaneous (SC) injection due to its short half-life. The purpose of the present study is to develop an improved sustained-release exenatide formulation with a therapeutic efficacy comparable to serial, twice-daily injections of exenatide. A novel SR formulation of exenatide, DA-3091, was prepared by single-emulsion solvent evaporation using PLGA. It was administered by SC injection to ZDF rats in single exenatide doses of 0.1, 0.25, 0.5, 1 or 2 mg/kg. On the 28th, 49th and 70th days, a 1 or 2 mg/kg dose of DA-3091 was further administered to rats in dose groups of 1 or 2 mg/kg. The efficacy of DA-3091 was then compared with that of serial, twice-daily SC injections of an exenatide solution for 13 weeks. NFBG and HbA1c concentrations were decreased both significantly and linearly as the exenatide dose in DA-3091 increased. In addition, food intake and body weight were suppressed both significantly and dose-dependently. In equivalent or half doses of exenatide, the efficacy of DA-3091 was comparable to that of twice-daily injections of exenatide solution for 13 weeks. In conclusion, DA-3091 has the potential to be clinically effective when administered every 3 weeks, or less frequently, which promises to significantly improve patient compliance.

Long-lasting enfuvirtide carrier pentasaccharide conjugates with potent anti-human immunodeficiency virus type 1 activity.

Enfuvirtide (also known as Fuzeon, T-20, or DP-178) is an antiretroviral fusion inhibitor which prevents human immunodeficiency virus type 1 (HIV-1) from entering host cells. This linear 36-mer synthetic peptide is indicated, in combination with other antiretroviral agents, for the treatment of HIV-1-infected individuals and AIDS patients with multidrug-resistant HIV infections. Although enfuvirtide is an efficient anti-HIV-1 drug, its clinical use is limited by a short plasma half-life, i.e., approximately 2 h, which requires twice-daily subcutaneous injections, often resulting in skin sensitivity reaction side effects at the injection sites. Ultimately, 80% of patients stop enfuvirtide treatment within 6 months because of these side effects. We report on the development of long-lasting enfuvirtide conjugates by the use of the site-specific conjugation of enfuvirtide to an antithrombin-binding carrier pentasaccharide (CP) through polyethylene glycol (PEG) linkers of various lengths. These conjugates showed consistent and broad anti-HIV-1 activity in the nanomolar range. The coupling of the CP to enfuvirtide only moderately affected the in vitro anti-HIV-1 activity in the presence of antithrombin. Most importantly, one of these conjugates, enfuvirtide-PEG(12)-CP (EP40111), exhibited a prolonged elimination half-life of more than 10 h in rat plasma compared to the half-life of native enfuvirtide, which was 2.8 h. On the basis of the pharmacokinetic properties of antithrombin-binding pentasaccharides, the anticipated half-life of EP40111 in humans would putatively be about 120 h, which would allow subcutaneous injection once a week instead of twice daily. In conclusion, EP40111 is a promising compound with strong potency as a novel long-lasting anti-HIV-1 drug.

Switch From Enfuvirtide to Raltegravir in Patients With Undetectable Viral Load: Efficacy and Safety at 24 Weeks in a Montreal Cohort

Switch From Enfuvirtide to Raltegravir in Patients With Undetectable Viral Load: Efficacy and Safety at 24 Weeks in a Montreal Cohort

Soluble RANKL Induces High Bone Turnover and Decreases Bone Volume, Density, and Strength in Mice

Receptor activator for nuclear factor-kappa B ligand (RANKL) is an essential mediator of osteoclastogenesis. We hypothesized that administration of soluble RANKL to mice would result in high turnover and deleterious effects on both cortical and trabecular bone. For 10 days, 10-week-old C57BL/6J female mice (n = 12/group) were given twice-daily subcutaneous injections of human recombinant RANKL (0.4 or 2 mg/kg/day) or inert vehicle (VEH). Bone turnover was greatly accelerated by RANKL, as evidenced by the 49-84% greater levels of serum TRAP-5b (bone resorption marker) and 300-400% greater levels of serum alkaline phosphatase (bone formation marker). RANKL resulted in significantly greater endocortical bone erosion surface (79-83%) and periosteal bone formation rate (64-87%) vs. VEH. Microcomputed tomographic (microCT) analysis of the proximal tibia indicated a reduction in trabecular volume fraction (-84%) for both doses of RANKL. Cortical bone geometry and strength were also negatively influenced by RANKL. MicroCT analysis of the femoral diaphysis indicated significantly lower cortical bone volume (-10% to -13%) and greater cortical porosity (8-9%) relative to VEH. Biomechanical testing of the femur diaphysis revealed significantly lower maximum bending load (-19% to -25%) vs. VEH. Bone strength remained correlated with bone mass, independent of RANKL stimulation of bone turnover. These findings are consistent with the hypothesis that soluble RANKL could be an important etiologic factor in pathologic bone loss. RANKL also has potential utility as a model for studying the consequences of high bone turnover on bone quality and strength in animals.

Long-term efficacy of leptin replacement in patients with Dunnigan-type familial partial lipodystrophy

The Dunnigan-type familial partial lipodystrophy (FPLD) is characterized by a variable loss of fat from the extremities and trunk and excess subcutaneous fat in the chin and supraclavicular area. Associated metabolic abnormalities include hypoleptinemia, insulin resistance, and dyslipidemia. Our goal was to observe changes in metabolic parameters for patients with FPLD on long-term leptin replacement and to compare the metabolic characteristics seen in FPLD with those seen in generalized lipodystrophy (GL) from our previous studies. This was an open-label study of 6 patients with FPLD receiving maximal doses of oral antidiabetic and lipid-lowering medications at baseline. Recombinant leptin was given through twice-daily subcutaneous injections at a maximal dose of 0.08 mg/kg per day over 12 months to simulate normal to high normal physiologic levels. Triglycerides were reduced by 65% at 4 months (749 ± 331 to 260 ± 58 mg/dL) and significantly reduced at 12 months for 5 patients (433 ± 125 to 247 ± 69 mg/dL; P = .03). Total cholesterol also decreased (280 ± 49 to 231 ± 41 mg/dL; P = .01). Insulin sensitivity and fasting glucose levels (190 ± 26 to 151 ± 15 mg/dL; P < .01) improved. Glucose tolerance and glycosylated hemoglobin levels (8.4% ± 0.6% to 8.0% ± 0.4%; P = .07) did not change. As shown in patients with GL, patients with FPLD have improvement in triglycerides, fasting glucose, and insulin sensitivity with leptin replacement. In contrast to the patients with GL, the patients with FPLD are older, have higher leptin levels, and notably lower insulin secretion for a similar degree of hyperglycemia. Low-dose recombinant methionyl human leptin for patients with FPLD has an important role in improving triglycerides, beyond that of available lipid-lowering agents. In improving glycemic control, normalization of glucose tolerance in hypoinsulinemic patients with FPLD requires insulin and leptin therapy. This is the first study to examine the effects of long-term leptin replacement in patients with FPLD.

A Randomised Trial of Subcutaneous Intermittent Interleukin-2 without Antiretroviral Therapy in HIV-Infected Patients: The UK–Vanguard Study

Objective:The objective of the trial was to evaluate in a pilot setting the safety and efficacy of interleukin-2 (IL-2) therapy when used without concomitant antiretroviral therapy as a treatment for HIV infection.Design and Setting:This was a multicentre randomised three-arm trial conducted between September 1998 and March 2001 at three clinical centres in the United Kingdom.Participants:Participants were 36 antiretroviral treatment naïve HIV-1-infected patients with baseline CD4 T lymphocyte counts of at least 350 cells/mm3.Interventions:Participants were randomly assigned to receive IL-2 at 15 million international units (MIU) per day (12 participants) or 9 MIU/day (12 participants) or no treatment (12 participants). IL-2 was administered by twice-daily subcutaneous injections for five consecutive days every 8 wk.Outcome Measures:Primary outcome was the change from baseline CD4 T lymphocyte count at 24 wk. Safety and plasma HIV RNA levels were also monitored every 4 wk through 24 wk. The two IL-2 dose groups were combined for the primary analysis.Results:Area under curve (AUC) for change in the mean CD4 T lymphocyte count through 24 wk was 129 cells/mm3 for those assigned IL-2 (both dose groups combined) and 13 cells/mm3 for control participants (95% CI for difference, 51.3–181.2 cells/mm3; p = 0.0009). Compared to the control group, significant increases in CD4 cell count were observed for both IL-2 dose groups: 104.2/mm3 (p = 0.008) and 128.4 cells/mm3 (p = 0.002) for the 4.5 and 7.5 MIU dose groups, respectively. There were no significant differences between the IL-2 (0.13 log10 copies/ml) and control (0.09 log10 copies/ml) groups for AUC of change in plasma HIV RNA over the 24-wk period of follow-up (95% CI for difference, −0.17 to 0.26; p = 0.70). Grade 4 and dose-limiting side effects were in keeping with those previously reported for IL-2 therapy.Conclusions:In participants with HIV infection and baseline CD4 T lymphocyte counts of at least 350 cells/mm3, intermittent subcutaneous IL-2 without concomitant antiretroviral therapy was well tolerated and produced significant increases in CD4 T lymphocyte counts and did not adversely affect plasma HIV RNA levels.

Chronic nicotine treatment increases GABAergic input to striatal neurons

Recent studies suggest the involvement of the dorsal striatum in the advanced stages of drug addiction as well as motor functions. We investigated the effect of chronic nicotine treatment on GABAergic synaptic transmission in the striatum of mice. Intrastriatal stimulation evoked GABAA receptor-mediated polysynaptic inhibitory postsynaptic currents more frequently in medium-sized spiny projection neurons of mice treated chronically with nicotine (1 mg/kg, twice-daily subcutaneous injections for 10-15 days) than in those of PBS-treated mice. The multiphasic inhibitory postsynaptic currents consisted of monosynaptic early and polysynaptic, nicotinic acetylcholine receptor-mediated late components. Dihydro-beta-erythroidine, an antagonist of the non-alpha7nicotinic acetylcholine receptor, suppressed only the late inhibitory postsynaptic current. These results suggest that chronic nicotine treatment increases GABAergic input to projection neurons in the dorsal striatum.