Adverse vacuolation in multiple tissues in cynomolgus monkeys following repeat-dose administration of a PEGylated protein.

PEGylation is considered a safe mechanism to enhance the pharmacokinetics (PK) and pharmacodynamics (PD) of biotherapeutics. Previous studies using PEGylation as a PK enhancement tool have reported benign PEG-related vacuolation in multiple tissues. This paper establishes a threshold for PEG burden beyond which there are alterations in tissue architecture that could potentially lead to dysfunction. As part of the nonclinical safety assessment of Compound A, a 12 kDa protein conjugated to a 40 kDa branched PEG molecule, monkeys were dosed subcutaneously twice weekly for 3 months at protein doses resulting in weekly PEG doses of 8, 24, 120, or 160 mg/kg. Consistent with previous reports with PEGylated biomolecules, Compound A administration resulted in intracellular vacuoles attributed to the PEG moiety in macrophages in numerous tissues and epithelial cells in the choroid plexus and kidney. Vacuolation occurred at all doses with dose-dependent severity and no evidence of recovery up to 2 months after dosing cessation. The vacuolation was considered nonadverse at PEG doses ≤120 mg/kg/week. However, at 160 mg/kg/week PEG, the vacuolation in choroid plexus, pituitary gland, kidney, and choroid of the eye was considered adverse due to significant alterations of tissue architecture that raised concern for the possibility of compromised tissue function. To our knowledge, this is the first report of potentially adverse cellular consequences of PEG accumulation in tissues other than kidney. Furthermore, the lack of reversibility of vacuolation coupled with the lack of a biomarker for intracellular PEG accumulation highlights a potential risk that should be weighed against the benefits of PK/PD enhancement for long-term administration of PEGylated compounds at high doses.

Fish oil omega-3 fatty acids partially prevent lipid-induced insulin resistance in human skeletal muscle without limiting acylcarnitine accumulation.

Acylcarnitine accumulation in skeletal muscle and plasma has been observed in numerous models of mitochondrial lipid overload and insulin resistance. Fish oil n3PUFA (omega-3 polyunsaturated fatty acids) are thought to protect against lipid-induced insulin resistance. The present study tested the hypothesis that the addition of n3PUFA to an intravenous lipid emulsion would limit muscle acylcarnitine accumulation and reduce the inhibitory effect of lipid overload on insulin action. On three occasions, six healthy young men underwent a 6-h euglycaemic-hyperinsulinaemic clamp accompanied by intravenous infusion of saline (Control), 10% Intralipid® [n6PUFA (omega-6 polyunsaturated fatty acids)] or 10% Intralipid®+10% Omegaven® (2:1; n3PUFA). The decline in insulin-stimulated whole-body glucose infusion rate, muscle PDCa (pyruvate dehydrogenase complex activation) and glycogen storage associated with n6PUFA compared with Control was prevented with n3PUFA. Muscle acetyl-CoA accumulation was greater following n6PUFA compared with Control and n3PUFA, suggesting that mitochondrial lipid overload was responsible for the lower insulin action observed. Despite these favourable metabolic effects of n3PUFA, accumulation of total muscle acylcarnitine was not attenuated when compared with n6PUFA. These findings demonstrate that n3PUFA exert beneficial effects on insulin-stimulated skeletal muscle glucose storage and oxidation independently of total acylcarnitine accumulation, which does not always reflect mitochondrial lipid overload.

Improved biomedical and psychological outcomes 1 year after structured education in flexible insulin therapy for people with type 1 diabetes: the U.K. DAFNE experience.

OBJECTIVE: DAFNE (Dose Adjustment For Normal Eating), a structured education program in flexible insulin therapy, has been widely adopted in the U.K. after validation in a randomized trial. To determine benefits in routine practice, we collected biomedical and psychological data from all participants attending during a 12-month period. RESEARCH DESIGN AND METHODS: HbA(1c), weight, self-reported hypoglycemia awareness, severe hypoglycemia frequency, PAID (Problem Areas In Diabetes), HADS (Hospital Anxiety and Depression Scale), and EuroQol Group 5-Dimension Self-Report Questionnaire scores were recorded prior to DAFNE and after 1 year. RESULTS: Complete baseline and follow-up HbA(1c) data were available for 639 (54.9%) of 1,163 attendees. HbA(1c) fell from 8.51 ± 1.41 (mean ± SD) to 8.24 ± 1.29% (difference 0.27 [95% CI 0.16-0.38]; P < 0.001), with a greater mean fall of 0.44% from baseline HbA(1c) >8.5%. Severe hypoglycemia rate fell from 1.7 ± 8.5 to 0.6 ± 3.7 episodes per person per year (1.1 [0.7-1.4]) and hypoglycemia recognition improved in 43% of those reporting unawareness. Baseline psychological distress was evident, with a PAID score of 25.2 and HADS scores of 5.3 (anxiety) and 4.8 (depression), falling to 16.7 (8.5 [6.6-10.4]), 4.6 (0.7 [0.4-1.0]), and 4.2 (0.6 [0.3-0.8]), respectively (all P < 0.001 at 1 year). Clinically relevant anxiety and depression (HADS ≥ 8) fell from 24.4 to 18.0% and 20.9 to 15.5%, respectively. CONCLUSIONS: A structured education program delivered in routine clinical practice not only improves HbA(1c) while reducing severe hypoglycemia rate and restoring hypoglycemia awareness but also reduces psychological distress and improves perceived well-being.

Histochemical and morphometric characterization of broncho-pneumonia in calves caused by infection with Mycoplasma bovis.

The aim of this study was to identify morphometric histological features of pneumonia caused by Mycoplasma bovis in calves. Eight three-month-old calves were infected with M. bovis and samples of their lung tissue, three weeks after exposure, compared to samples from four uninfected calves. In the uninfected animals the goblet cells were clustered in the crypt area of the epithelial folds, while in the infected calves they had migrated towards the tips of the folds and were distributed evenly throughout the folds. In infected lung tissue there was goblet cell hyperplasia and metaplasia in the bronchioles and an increased epithelial height. Goblet cell mucin in uninfected calves was acidic, but in infected calves most goblet cells contained neutral mucins. These morphometric and histochemical bronco-epithelial changes may be able to be used as markers of the severity of bovine respiratory mycoplasmosis.

Investigation of the haemodynamic effects of exenatide in healthy male subjects.

AIMS: In clinical studies of glucagon-like peptide-1 (GLP-1) agonists used in the management of patients with type 2 diabetes, there is often a small accompanying fall in blood pressure. The mechanism underlying this effect is not known, although exenatide, a GLP-1 mimetic, has acute regional vasodilator properties in rats. We have therefore studied the haemodynamic effects of exenatide in healthy male volunteers. METHODS: We compared the effects of a single 10 µg subcutaneous injection of exenatide with placebo in a double-blind, randomized, crossover study. For 2 h after dosing, haemodynamic measurements were made using a Finometer, venous occlusion plethysmography and Doppler ultrasound. The urine sodium : creatinine excretion ratio was determined. RESULTS: At the end of the study when exenatide was compared with placebo, heart rate had risen by a mean of 8.2 (95% CI 4.2, 12.2, P < 0.01) beats min(-1) , cardiac output by a mean of 1.2 (95% CI 0.42, 20.3, P < 0.05) l min(-1) and total peripheral resistance had fallen by 120 (95% CI -8, -233, P < 0.05) dyn s cm(-5) .There were no differences in blood pressure. The urinary sodium : creatinine ratio was increased by mean 12.4 (95% CI 4.6, 20.2, P < 0.05) mmol mmol(-1) when exenatide was compared with placebo. CONCLUSIONS: Exenatide has significant haemodynamic effects in healthy volunteers. The results of this study are consistent with exenatide having both vasodilator and natriuretic properties. The vascular changes may contribute to the hypotensive effect of exenatide when used chronically in patients with diabetes.

Toxicology and toxicokinetics of oral pantoprazole in neonatal and juvenile dogs.

BACKGROUND: Pantoprazole is an irreversible inhibitor of H(+) /K(+) adenosine triphosphatase proton pump. This study encompassed the period of postnatal stomach development to determine whether immature animals are uniquely sensitive to progression of PPI-induced enterochromaffin-like cell hyperplasia. METHODS: Pantoprazole was administered to beagle dogs at 3, 10, or 30 mg/kg/day (10/sex/group) from PND 1 for 13 weeks, subsets of animals had a 13-week recovery period. Clinical signs, body weights, growth, clinical chemistry, and neurobehavioral endpoints were assessed. Selected organs were weighed and histologically examined. RESULTS: There were no effects on body weights, growth, landmarks of physical and reproductive development, or sensory and neurobehavioral function. Cholesterol and triglyceride levels were increased at 10 and 30 mg/kg/day, but resolved during the recovery period. Stomach weight was increased at all doses, but after recovery the differences in stomach weights resolved for females although male stomach weights remained slightly increased. Pantoprazole-related microscopic findings in the stomach consisted of increased mucosal height, glandular necrosis, and glandular dilation at all doses; and ECL cell hyperplasia, parietal cell vacuolation, and atrophy of chief cells are noted at 10 and/or 30 mg/kg/day. There was a partial recovery of these microscopic changes indicated by a decreased incidence and/or severity of increased mucosal height, glandular necrosis, ECL cell hyperplasia, and chief cell atrophy, and complete resolution of other microscopic observations. CONCLUSION: Pantoprazole administered to beagles from PND 1 for 13 weeks resulted in findings similar to those in adult dogs and juvenile dogs, which showed no increase in severity or progression of ECL hyperplasia.

Metastatic lung and pleural malignancy presenting as bilateral acute anterior uveitis.

Anterior uveitis is associated with a variety of underlying systemic diseases but the association between bilateral acute anterior uveitis (BAAU) and lung and pleural malignancy is not widely recognized. The case is described here of a 61-year-old woman presenting to an eye clinic with BAAU. A routine chest radiograph performed principally to exclude pulmonary sarcoidosis revealed an intrapulmonary mass and she was subsequently found to have widespread lung and pleural malignancies. Evidence is discussed that suggests a link and potential aetiology between BAAU and lung and pleural malignancies. The present case shows the virtue of requesting a chest radiograph in patients presenting with BAAU, even in the absence of other symptoms or clinical findings.