Biology and postnatal development of organ systems of cynomolgus monkeys (Macaca fascicularis).

BACKGROUND: The cynomolgus macaque has become the most used non-human primate species in nonclinical safety assessment during the past decades. METHODS: This review summarizes the biological data and organ system development milestones of the cynomolgus macaque available in the literature. RESULTS: The cynomolgus macaque is born precocious relative to humans in some organ systems (e.g., nervous, skeletal, respiratory, and gastrointestinal). Organ systems develop, refine, and expand at different rates after birth. In general, the respiratory, gastrointestinal, renal, and hematopoietic systems mature at approximately 3 years of age. The female reproductive, cardiovascular and hepatobiliary systems mature at approximately 4 years of age. The central nervous, skeletal, immune, male reproductive, and endocrine systems complete their development at approximately 5 to 9 years of age. CONCLUSIONS: The cynomolgus macaque has no meaningful developmental differences in critical organ systems between 2 and 3 years of age for use in nonclinical safety assessment.

Method of measuring effects of study procedures in single and pair housed New Zealand White rabbits (Oryctolagus cuniculus).

Social housing of laboratory rabbits is encouraged and thought to improve animal welfare due to the social nature of this species. However, there is limited published information comparing the physiologic and cardiovascular (CV) effects of paired and single housed adult female rabbits in commonly used laboratory caging. This study describes measurement of heart rate, systolic blood pressure, activity level, body temperature and pairing methods in four female New Zealand White rabbits that were previously implanted with M10 cardiovascular telemetry devices. Data was collected in single housed rabbits having no history of social housing while they were undisturbed in the home cage, during restraint, intramuscular injections and intravenous blood collection. The same animals were then placed in compatible pairs and housed in conventional Allentown caging. As expected, we found increased activity in paired rabbits but no significant differences in body temperatures, and CV parameters in single and paired rabbits undergoing the same procedures. These data suggest that paired rabbits can be used for safety pharmacology studies with minimal impact to data, while supporting improved animal welfare.

Investigation of the thermodynamic drivers of the interaction between the high mobility group box domain of Sox2 and bacterial lipopolysaccharide.

Gastric cancer is associated with high mortality and is preceded by an infection with Helicobacter pylori (H. pylori). H. pylori stimulates inflammation which involves the activation of Toll-like receptor 4 by lipopolysaccharide molecules from the H. pylori. This leads to chronic inflammation that can eventually lead to gastric cancer. Sox2 is a member of the high mobility group (HMG) box family of proteins, and recent studies have shown that HMG box proteins can modulate immune response by altering signaling to Toll-like receptors. Sox2 is overexpressed in most types of cancer with the exception of gastric cancer where expression of Sox2 is decreased. Here, we demonstrate that Sox2 can bind LPS and we investigated the thermodynamic drivers of the Sox2/LPS interaction.

AAV2-mediated gene delivery to monkey putamen: evaluation of an infusion device and delivery parameters.

In this study, a modified infusion procedure and a novel infusion device designed for use in humans (Clinical Device B) were evaluated for delivery of recombinant adeno-associated virus (AAV2) to brain. The device is composed of 1.2 m of fused silica inserted through a 24.6-cm surgical steel cannula designed to fit a standard Leksell clinical stereotaxic frame and micro-infusion syringe pump. AAV2 encoding the human aromatic l-amino acid decarboxylase gene (AAV-hAADC-2) was infused into the putamen of 4 normal rhesus monkeys as a supportive study for a clinical trial in Parkinson's disease (PD) patients. Two infusion protocols were tested: a ramped procedure (slow stepwise increases in rate from 0.2 muL/min to 1 muL/min), thought to be essential for convection-enhanced delivery (CED), and a non-ramped infusion at a constant rate of 1 muL/min. The primary endpoints were safety evaluation of the infusion procedures and assessment of transgene expression at 5.5 weeks post-infusion. Clinical observations after vector infusions revealed no behavioral abnormalities during the study period. No differences in gross pathology with either the ramped or non-ramped infusion procedure were observed. Histopathology of the putamen was comparable with both procedures, and revealed only minimal localized inflammatory tissue reaction along the needle track in response to cannula placement and vector infusion. AADC immunohistochemistry demonstrated that vector was distributed throughout the putamen, with no significant difference in volume of immunostaining with either infusion procedure. Serum antibody levels against AAV2 vector exhibited a minor increase after infusion. These results validate the clinical utility of this new infusion device and non-ramped infusion conditions for intraputamenal gene therapy, and have the potential to impact a number of human diseases in which delivery of therapeutics to brain is indicated.

Telemetric uterine contraction model in preterm cynomolgus monkeys.

A telemetric-based model is presented for evaluation of uterine contractions and preterm labor (PTL) in pregnant cynomolgus monkeys. The model allows continuous monitoring of electromyography (EMG) and intrauterine pressure (IUP) as indicators of uterine activity. A pressure sensor was implanted into the amnion of pregnant monkeys on gestational day (GD) 120 +/- 3 and biopotential sensors were attached to the uterus. A telemetry transmitter was placed in a subcuticular pocket located in the flank. Venous catheters were tethered to the next room for dosing and blood sampling without disturbing the conscious animals. EMG and/or IUP were monitored continuously post-operatively. IUP is a reliable parameter for monitoring intrauterine activity, as demonstrated by a close relationship between bursts of activity in the EMG and increases in IUP. Animals close to term showed a basal level of uterine activity during the daytime, with irregular contractions of <10 mmHg. In the night, spontaneous contractions (10-40 mmHg; maximum between 18:00 and 01:00 h) appeared every 3-6 min. Artificial contractions of 15-40 mmHg that mimicked preterm labor were induced at any time of the day by infusion of 5-60 mU oxytocin (OT) per kilogram per hour. These contractions showed a dose-dependent response to OT, and were stable for up to 14 h of constant infusion of OT. Following withdrawal of oxytocin, contractions returned to baseline within 1h. No desensitization of oxytocin-induced contractions was observed when oxytocin was administered daily for up to several weeks. This telemetric model characterizes uterine contractions in non-human primates and provides an excellent method to evaluate pharmacological characteristics of drug candidates intended to treat PTL.