Delineation of biomarkers and molecular pathways of residual effects of fluoxetine treatment in juvenile rhesus monkeys by proteomic profiling

Fluoxetine(Prozac^(TM))is the only antidepressant approved by the US Food and Drug Administration(FDA)for the treatment of major depressive disorder(MDD)in children.Despite its considerable efficacy as a selective serotonin reuptake inhibitor,the possible long-term effects of fluoxetine on brain development in children are poorly understood.In the current study,we aimed to delineate molecular mechanisms and protein biomarkers in the brains of juvenile rhesus macaques(Macaca mulatta)one year after the discontinuation of fluoxetine treatment using proteomic and phosphoproteomic profiling.We identified several differences in protein expression and phosphorylation in the dorsolateral prefrontal cortex(DLPFC)and cingulate cortex(CC)that correlated with impulsivity in animals,suggesting that the GABAergic synapse pathway may be affected by fluoxetine treatment.Biomarkers in combination with the identified pathways contribute to a better understanding of the mechanisms underlying the chronic effects of fluoxetine after discontinuation in children.

Reproductive traits of polycystic ovary syndrome in female rhesus monkeys

The objective of this study was to set up a rhesus monkey model of polycystic ovary syndrome（PCOS）,which is globally prevalent among reproductive-aged human women,and to understand the reproductive traits of PCOS female monkeys.Six adult female rhesus monkeys aged 6-10 a,were divided into a PCOS group and a control group.The PCOS group were given two cycles of subcutaneous injections of propionic acid testosterone（PAT）,3.5 mg/kg body weight,on day 1,day 3,and day 5 of the menstrual cycle,respectively,and then given muscle injections of human chorionic gonadotropin（HCG）,350 IU/kg body wtight,on day 7,day 9,and day 11,respectively.Results showed that high levels of serum LH and T [（5.35±0.17） IU/L and（7.58±0.14） ng/mL,respectively],and a high ratio value of LH/FSH（5.35/1.30=4.12） were observed in the PCOS group.No significant differences were found in serum FSH,E2,and P in the PCOS group compared with those of the control.Polycystic ovaries in the PCOS monkeys were recorded by live ultrasound.The blastocysts rates of the PCOS vs.the control were 23.53% vs.66.67%,and there was a significant difference between the two groups.This study shows that PAT coupled with HCG can induce PCOS in rhesus monkeys in the short term.The reproductive features of PCOS monkeys were similar to those of PCOS patients.

Notch signaling dependent differentiation of cholangiocyte-like cells from rhesus monkey embryonic stem cells

Rhesus monkey embryonic stem（rES） cells have similar characteristics to human ES cells,and might be useful as a substitute model for preclinical research.Notch signaling is involved in the formation of bile ducts,which are composed of cholangiocytes.However,little is known about the role of Notch signaling in cholangiocytic commitment of ES cells.We analyzed the effect of Notch signaling on the induction of cholangiocyte-like cells from rES cells.About 80% of definitive endoderm（DE） cells were generated from rES cells after treatment with activin A.After treatment with BMP4 and FGF1 on matrigel coated wells in serum-free medium,rES-derived DE gave rise to cholangiocyte-like cells by expression of cholangiocytic specific proteins（CK7,CK18,CK19,CK20,and OV-6） and genes（GSTPi,IB4,and HNF1β）.At the same time,expression of Notch 1 and Notch 2 mRNA were detected during cell differentiation,as well as their downstream target genes such as Hes 1 and Hes 5.Inhibition of the Notch signal pathway by L-685458 resulted in decreased expression of Notch and their downstream genes.In addition,the proportion of cholangiocyte-like cells declined from ～90% to ～20%.These results suggest that Notch signaling may play a critical role in cholangiocytic development from ES cells.

Pharmacokinetics of recombinant human parathyroid hormone after subcutaneous administration in Rhesus monkeys by immunoradiometric assay

The purpose of this research was to study the pharmacokinetics and the bioavailability of recombinant human parathyroid hormone [rhPTH （1-34）] in Rhesus monkeys after single and multiple subcutaneous administration. An immunoradiometric assay （IRMA） was used to determine the plasma drug concentration of rhFFH （1-34） after giving single dose of 10, 20 and 40 ug/kg and daily dose of 40 ug/kg for 7 d by subcutaneous administration, and intravenous injection of 20 ug/kg in Rhesus monkeys. The pharmacokinetic parameters were calculated by noncompartmental analysis. The drug plasma level quantitation range was from 0.027 to 2.22 ng/mL. The intra- and inter-assay precision （CV） of analysis were less than 15%, and the average recovery was about 93.0% ± 8.6% - 116.5% ± 14.0%. After subcutaneous administration of rhPTH（1-34） at dose of 10, 20 and 40 ug/kg, the average Tmax was 0.67, 0.5 and 0.83 h, Cmax were 1.85 ± 0.05, 3.23 ± 0.25 and 7.15 ± 1.19 ng/mL, the AUC（0-∞） were 3.4 ± 0.6, 10.7 ± 1.3 and 12.6 ± 1.5 ng/h/mL, and terminal-phase elimination T1/2 were 0.72 ± 0.10, 1.15 ± 0.10 and 1.03 ± 0.06 h, respectively. The absolute bioavailability of rhPTH （1-34） was 46.96% after subcutaneous administration of 20 ug/kg. There was no evidence of accumulation during systemic exposure of rhPTH （1-34） upon multiple dosing in Rhesus monkeys. The IRMA assay method provide reasonable sensitivity and specificity for the pharrnacokinetic study of rhPTH （1-34） after subcutaneous or intravenous administration in Rhesus monkeys. The pharmacokinetic characteristic of rhPTH （1-34） in monkeys shows linear relationship with the dose administered subcutaneously.

A more consistent intraluminal rhesus monkey model of ischemic stroke

Endovascular surgery is advantageous in experimentally induced ischemic stroke because it causes fewer cranial traumatic lesions than invasive surgery and can closely mimic the pathophysiology in stroke patients. However, the outcomes are highly variable, which limits the accuracy of evaluations of ischemic stroke studies. In this study, eight healthy adult rhesus monkeys were randomized into two groups with four monkeys in each group： middle cerebral artery occlusion at origin segment （M1） and middle cerebral artery occlusion at M2 segment. The blood flow in the middle cerebral artery was blocked completely for 2 hours using the endovascular microcoil placement technique （1 mm × 10 cm） （undetachable）, to establish a model of cerebral ischemia. The microcoil was withdrawn and the middle cerebral artery blood flow was restored. A reversible middle cerebral artery occlusion model was identified by hematoxylin-eosin staining, digital subtraction angiography, magnetic resonance angiography, magnetic resonance imaging, and neurological evaluation. The results showed that the middle cerebral artery occlusion model was successfully established in eight adult healthy rhesus monkeys, and ischemic lesions were apparent in the brain tissue of rhesus monkeys at 24 hours after occlusion. The rhesus monkeys had symptoms of neurological deficits. Compared with the M1 occlusion group, the M2 occlusion group had lower infarction volume and higher neurological scores. These experimental findings indicate that reversible middle cerebral artery occlusion can be produced with the endovascular microcoil technique in rhesus monkeys. The M2 occluded model had less infarction and less neurological impairment, which offers the potential for application in the field of brain injury research.

Activation of extracellular signal-related kinases 1 and 2 in Sertoli cells in experimentally cryptorchid rhesus monkeys

Aim： To assess the spatiotemporal changes in the expression of extracellular signal-regulated kinases 1 and 2 （ERK1/ 2）, c-Jun N-terminal kinases （JNK） and p38 mitogen-activated protein kinases （MAPK） in response to heat stress in the cryptorchid testis, and to investigate a possible relation to Sertoli cell dedifferentiation. Methods： Immunohistochemistry and western blot were used to examine the expression and activation of ERK1/2, p38 and JNK in the cryptorchid testis at various stages after experimental cryptorchidism. Results： The abdominal temperature did not obviously change the total ERK1/2 expression but significantly activated phospho-ERK1/2 in the Sertoli cells of the cryptorchid testis. Heat stress increased total JNK expression in the Sertoli cells of the cryptorchid testis but did not activate phospho-JNK. Neither total p38 nor phospho-p38 was induced by heat stress in the Sertoli cells of the cryptorchid testis. Changes in the spatiotemporal expression of cytokeratin 18 （CK18）, a marker of immature or undifferentiated Sertoli cells, were induced in the cryptorchid testis in a pattern similar to the activation of ERK1/2. Condusion： The activation of ERK1/2 in the testis may be related to dedifferentiation of Sertoli cells under heat stress induced by experimental cryptorchidism.

Comparative study of the transfection efficiency of commonly used viral vectors in rhesus monkey (Macaca mulatta) brains

Viral vector transfection systems are among the simplest of biological agents with the ability to transfer genes into the central nervous system. In brain research, a series of powerful and novel gene editing technologies are based on these systems. Although many viral vectors are used in rodents, their full application has been limited in non-human primates. To identify viral vectors that can stably and effectively express exogenous genes within non- human primates, eleven commonly used recombinant adeno-associated viral and lentiviral vectors, each carrying a gene to express green or red fluorescence, were injected into the parietal cortex of four rhesus monkeys. The expression of fluorescent cells was used to quantify transfection efficiency. Histological results revealed that recombinant adeno-associated viral vectors, especially the serotype 2/9 coupled with the cytomegalovirus, human synapsin I, or Ca2~/calmodulin-dependent protein kinase II promoters, and lentiviral vector coupled with the human ubiquitin C promoter, induced higher expression of fluorescent cells, representing high transfection efficiency. This is the first comparison of transfection efficiencies of different viral vectors carrying different promoters and serotypes in non-human primates （NHPs）. These results can be used as an aid to select optimal vectors to transfer exogenous genes into the central nervous system of non-human primates.

Tissue-engineered rhesus monkey nerve grafts for the repair of long ulnar nerve defects:similar outcomes to autologous nerve grafts

Acellular nerve allografts can help preserve normal nerve structure and extracellular matrix composition. These allografts have low immunogenicity and are more readily available than autologous nerves for the repair of long-segment peripheral nerve defects. In this study, we repaired a 40-mm ulnar nerve defect in rhesus monkeys with tissue-engineered peripheral nerve, and compared the outcome with that of autograft. The graft was prepared using a chemical extract from adult rhesus monkeys and seeded with allogeneic Schwann cells. Pathomo- rphology, electromyogram and immunohistochemistry findings revealed the absence of palmar erosion or ulcers, and that the morphology and elasticity of the hypothenar eminence were normal 5 months postoperatively. There were no significant differences in the mean peak compound muscle action potential, the mean nerve conduction velocity, or the number of neurofilaments between the experimental and control groups. However, outcome was significantly better in the experimental group than in the blank group. These findings suggest that chemically extracted allogeneic nerve seeded with autologous Schwann cells can repair 40-mm ulnar nerve defects in the rhesus monkey. The outcomes are similar to those obtained with autologous nerve graft.

A simple model of radial nerve injury in the rhesus monkey to evaluate peripheral nerve repair

Current research on bone marrow stem cell transplantation and autologous or xenogenic nerve transplantation for peripheral nerve regeneration has mainly focused on the repair of peripher-al nerve defects in rodents. In this study, we established a standardized experimental model of radial nerve defects in primates and evaluated the effect of repair on peripheral nerve injury. We repaired 2.5-cm lesions in the radial nerve of rhesus monkeys by transplantation of autografts, acellular allografts, or acellular allografts seeded with autologous bone marrow stem cells. Five months after surgery, regenerated nerve tissue was assessed for function, electrophysiology, and histomorphometry. Postoperative functional recovery was evaluated by the wrist-extension test. Compared with the simple autografts, the acellular allografts and allografts seeded with bone marrow stem cells facilitated remarkable recovery of the wrist-extension functions in the rhesus monkeys. This functional improvement was coupled with radial nerve distal axon growth, a higher percentage of neuron survival, increased nerve fiber density and diameter, increased myelin sheath thickness, and increased nerve conduction velocities and peak amplitudes of compound motor action potentials. Furthermore, the quality of nerve regeneration in the bone marrow stem cells-laden allografts group was comparable to that achieved with autografts. The wrist-extension test is a simple behavioral method for objective quantification of peripheral nerve regeneration.

Sleeve bridging of the rhesus monkey ulnar nerve with muscular branches of the pronator teres: multiple amplification of axonal regeneration

Multiple-bud regeneration, i.e., multiple amplification, has been shown to exist in peripheral nerve regeneration. Multiple buds grow towards the distal nerve stump during proximal nerve fiber regeneration. Our previous studies have verified the limit and validity of multiple ampli- fication of peripheral nerve regeneration using small gap sleeve bridging of small donor nerves to repair large receptor nerves in rodents. The present study sought to observe multiple ampli- fication of myelinated nerve fiber regeneration in the primate peripheral nerve. Rhesus monkey models of distal ulnar nerve defects were established and repaired using muscular branches of the right forearm pronator teres. Proximal muscular branches of the pronator teres were su- tured into the distal ulnar nerve using the small gap sleeve bridging method. At 6 months after suture, two-finger flexion and mild wrist flexion were restored in the ulnar-sided injured limbs of rhesus monkey. Neurophysiological examination showed that motor nerve conduction veloc- ity reached 22.63 _＋ 6.34 m/s on the affected side of rhesus monkey. Osmium tetroxide staining demonstrated that the number of myelinated nerve fibers was 1,657 ＋ 652 in the branches of pronator teres of donor, and 2,661 ~ 843 in the repaired ulnar nerve. The rate of multiple amplification of regenerating myelinated nerve fibers was 1.61. These data showed that when muscular branches of the pronator teres were used to repair ulnar nerve in primates, effective regeneration was observed in regenerating nerve fibers, and functions of the injured ulnar nerve were restored to a certain extent. Moreover, multiple amplification was subsequently detected in ulnar nerve axons.

Establishment of AIDS Animal Model with SIVmac239 Infected Chinese Rhesus Monkey

In the present research,two Chinese rhesus monkeys were inoculated intravenously with 5000 TCID50 of SIVmac239. The changes in the numbers of CD4+ T lymphocyte in peripheral blood,plasma viral loads,proviral DNA and humoral antibodies against virus were periodically monitored during 121 days. At the early stage of infection,proviral DNA had been detected in PBMCs,and infectious SIVmac239 virus had been isolated from PBMCs. At the same period,the numbers of CD4+ T lymphocytes were significantly decreased,and maintained at low level during the 121-day period of infection. Plasma viral loads reached the peak at week 2 post-inoculation and kept at a steady state subsequently. Moreover,antibodies against viral proteins were detected from plasma. All the results showed that the two Chinese rhesus monkeys had been infected with SIVmac239 successfully. This animal model can be applied for further AIDS researches.

Establishment of a rhesus monkey model of middle cerebral artery ischemia and reperfusion using a microcatheter embolization method

Nonhuman primates are closest to humans in terms of lineage, and middle cerebral artery ischemia/reperfusion responses of nonhuman primates are most similar to ischemic stroke in humans. Therefore, nonhuman primates could be utilized to simulate the process of ischemic stroke in the human. Few studies, however, have reported the use of endovascular technology to establish a rhesus monkey stroke model. In the present study, seven adult, male, rhesus monkeys were selected and, following anesthesia, a microcatheter was inserted into one side of the middle cerebral artery via the femoral artery to block blood flow, thereby resulting in middle cerebral artery occlusion. After 2 hours, the microcatheter was withdrawn to restore the middle cerebral artery blood flow and to establish ischemia/reperfusion. Results from angiography and magnetic resonance angiography confirmed occlusion and reopening of the middle cerebral artery. Magnetic resonance imaging revealed the existence of ischemic brain lesions, and neurological examination showed sustained functional deficits following surgery. The rhesus monkey middle cerebral artery ischemia/reperfusion models established by microcatheter embolization had the advantage of non-craniotomy invasion and reproducibility. The scope and degree of ischemic damage using this model was controllable. Therefore, this nonhuman primate model is an ideal model for cerebral ischemia and reperfusion.

Rhesus monkey neural stem cell transplantation promotes neural regeneration in rats with hippocampal lesions

Rhesus monkey neural stem cells are capable of differentiating into neurons and glial cells. Therefore, neural stem cell transplantation can be used to promote functional recovery of the nervous system. Rhesus monkey neural stem cells （1 ×10^5 cells/μL） were injected into bilateral hippocampi of rats with hippocampal lesions. Confocal laser scanning microscopy demonstrated that green fluorescent protein-la- beled transplanted cells survived and grew well. Transplanted cells were detected at the lesion site, but also in the nerve fiber-rich region of the cerebral cortex and corpus callosum. Some transplanted cells differentiated into neurons and glial cells clustering along the ventricular wall, and integrated into the recipient brain. Behavioral tests revealed that spatial learning and memory ability improved, indicating that rhesus monkey neural stem cells noticeably improve spatial learning and memory abilities in rats with hippocampal lesions.

A novel large animal model of recurrent migraine established by repeated administration of inflammatory soup into the dura mater of the rhesus monkey

Several animal models of migraine have been established, and those based on trigeminovascular system activation are widely accepted. How- ever, most of these models have been established on lower animals, such as rodents, and involve only a single administration of a noxious stimulus. In this study, an inflammatory soup （10 μL）, consisting of prostaglandin E2 （0.2 mM）, serotonin （2 mM）, bradykinin （2 raM） and histamine （2 raM）, was injected into the dura mater of conscious rhesus monkeys through an indwelling catheter. The infusion started on day 8 and was repeated every 3 days, for a total of six administrations, to induce neurogenic inflammation. We performed behavioral assessments and measured the expression of the oncogene c-fos, neuronal nitric oxide synthase （nNOS） and calcitonin gene related peptide （CGRP） ill the trigeminal system and in multiple brain regions involved in pain processing by immunohistochemical staining. Compared with monkeys in the control group, three of the four animals in the inflammatory soup group displayed decreased motor behaviors, and two showed increased ipsilateral nose and mouth secretions during the stimulus period. Higher expression levels of c-fos, nNOS and CGRP were found in various brain areas of experimental animals compared with controls, including the trigeminal nucleus caudalis, thalamus, hypothalamus, midbrain, pons and other areas involved in pain perception. These results suggest that repeated inflammatory soup stimulation of the dura activates the trigeminovascular system and produces migraine-like pathological changes and abnormal behaviors in conscious rhesus monkeys.

F-heparin modified intraocular lenses in Rhesus monkeys

AIMIn order to improve the biocompatibility of intraocular lenses (IOL), the polymethylmethacrylate (PMMA) IOL was modified with F-heparin.

Excitatory amino acid changes in the brains of rhesus monkeys following selective cerebral deep hypothermia and blood flow occlusion

Selective cerebral deep hypothermia and blood flow occlusion can enhance brain tolerance to ischemia and hypoxia and reduce cardiopulmonary complications in monkeys. Excitotoxicity induced by the release of a large amount of excitatory amino acids after cerebral ischemia is the major mechanism underlying ischemic brain injury and nerve cell death. In the present study, we used selective cerebral deep hypothermia and blood flow occlusion to block the bilateral common carotid arteries and/or bilateral vertebral arteries in rhesus monkey, followed by reperfusion using Ringer＇s solution at 4~C. Microdialysis and transmission electron microscope results showed that selective cerebral deep hypothermia and blood flow occlusion inhibited the release of glutamic acid into the extracellular fluid in the brain frontal lobe and relieved pathological injury in terms of the ultrastructure of brain tissues after severe cerebral ischemia. These findings indicate that cerebral deep hypothermia and blood flow occlusion can inhibit cytotoxic effects and attenuate ischemic/ hypoxic brain injury through decreasing the release of excitatory amino acids, such as glutamic acid.

Characteristics of diffusion-tensor imaging for healthy adult rhesus monkey brains

Diffusion-tensor imaging can be used to observe the microstructure of brain tissue. Fractional ani- sotropy reflects the integrity of white matter fibers. Fractional anisotropy of a young adult brain is low in gray matter, high in white matter, and highest in the splenium of the corpus callosum. Thus, we selected the anterior and posterior limbs of the internal capsule, head of the caudate nucleus, semioval center, thalamus, and corpus callosum （splenium and genu） as regions of interest when using diffusion-tensor imaging to observe fractional anisotropy of major white matter fiber tracts and the deep gray matter of healthy rhesus monkeys aged 4-8 years. Results showed no laterality dif- ferences in fractional anisotropy values. Fractional anisotropy values were low in the head of cau- date nucleus and thalamus in gray matter. Fractional anisotropy values were highest in the sple- nium of corpus callosum in the white matter, followed by genu of the corpus callosum and the pos- terior limb of the internal capsule. Fractional anisotropy values were lowest in the semioval center and posterior limb of internal capsule. These results suggest that fractional anisotropy values in major white matter fibers and the deep gray matter of 4-8-year-old rhesus monkeys are similar to those of healthy young people.

Sidiming attenuates morphine withdrawal syndrome and nitric oxide (synthase) levels in morphine-dependent rats and rhesus monkeys

The present study analyzed the effects of Sidiming, a Chinese herbal compound, on withdrawal syndrome, body weight loss, and serum levels of nitric oxide and its synthase in morphine- dependent rats and rhesus monkeys. These effects were compared with clonidine, an active control drug used for clinical treatment. Results showed that 4 and 8 g/kg Sidiming, respectively, significantly suppressed morphine withdrawal syndrome and reduced body mass loss in morphine-dependent rats. In addition, 2.4 and 4.8 g/kg Sidiming, respectively, significantly attenuated withdrawal syndrome in rhesus monkeys. High-dose Sidiming （8 g/kg in rats and 4.8 g/kg in rhesus monkeys） led to significantly inhibited serum levels of nitric oxide and its synthase in morphine-dependent rats and rhesus monkeys, which were greater than clonidine. These findings suggested that Sidiming treatment attenuated withdrawal syndrome in morphine-dependent rats and rhesus monkeys by inhibiting serum nitric oxide and its synthase.

THE ESOPHAGEAL CARCINOMA OF RHESUS MONKEYS FROM TAIHANG MOUNTAIN AREA OF HIGH MORBIDITY OF ESOPHAGEAL CARCINOMA

Taihang Mountain area, a high Incidence area of human esophageal cancer in Northern China. 124 Rhesus monkeys (Macacs Mulatta) were caught in the area in January 1989. Among them, two monkeys died of esophageal carcinoma in 1990. Case 1, a male monkey about 6. 5 yean old and weighing 14. 5 kg, had symptoms of salivation, vomiting and dysphagia in Fabruary 1990. The symptoms became gradually more serious and died in march 1990. Postmortem examination revealed a huge tumor in the distal segment of esophagus, causing severe structure of the organ. The tumor was classified as medullary type and histopathologically diagnosed as a well differentiated squamous cell carcinoma, with metastases to mediastinum and lymph nodes of right gastric group. Case 2, a female monkey ablut 11-year-old and weighing 10. 0 kg, showed loss of appetite, tiredness, somnolence, caughing and vomiting in September and died in December 1990. Autopsy revealed an annular tumor involving the whole clcumference of lower portion of the esophagus. The tumor was of ulcerative type and diagnosed as a well differentiated squamous cell carcinoma. The symptoms and pathological changes of the two monkeys showed high similarity to esophageal cancer in humen. We believe that the present findings would provide important leads for further study to clarify the etiology and pathogenesis ofhuman esophageal cancer in this high Incidence area of esophageal cancer.of

Percutaneous transhepatic portal catheterization guided by ultrasound technology for islet transplantation in rhesus monkey

BACKGROUND:Pig islet xenotransplantation has the potential to overcome the shortage of donated human islets for islet cell transplantation in type 1 diabetes.Testing in nonhuman primate models is necessary before clinical application in humans.Intraportal islet transplantation in monkeys is usually performed by surgical infusion during laparotomy or laparoscopy.In this paper,we describe a new method of percutaneous transhepatic portal catheterization(PTPC) as an alternative to current methods of islet transplantation in rhesus monkeys.METHODS:We performed ultrasound-guided PTPC in five adult rhesus monkeys weighing 7-8 kg,with portal vein catheterization confirmed by digital subtraction angiography.We monitored for complications in the thoracic and abdominal cavity.To evaluate the safety of ultrasound-guided PTPC,we recorded the changes in portal pressure throughout the microbead transplantation procedure.RESULTS:Ultrasound-guided PTPC and infusion of 16 000 microbeads/kg body weight into the portal vein was successful in all five monkeys.Differences in the hepatobiliary anatomy of rhesus monkeys compared to humans led to a higher initial complication rate.The first monkey died of abdominal hemorrhage 10 hours post-transplantation.The second suffered from a mild pneumothorax but recovered fully after taking only conservative measures.After gaining experience with the first two monkeys,we decreased both the hepatic puncture time and the number of puncture attempts required,with the remaining three monkeys experiencing no complications.Portal pressures initially increased proportional to the number of transplanted microbeads but returned to preinfusion levels at 30 minutes post-transplantation.The changes in portal pressures occurring during the procedure were not significantly different.CONCLUSIONS:Ultrasound-guided PTPC is an effective,convenient,and minimally invasive method suitable for use in non-human primate models of islet cell transplantation provided that care is taken with hepatic puncture.Its advantages must be weighed against the risks of procedure-related complications.