Prenatal ontogeny as a susceptibility period for cortical GABA neuron disturbances in schizophrenia

Cognitive deficits in schizophrenia have been linked to disturbances in GABA neurons in the prefrontal cortex (PFC). Furthermore, cognitive deficits in schizophrenia appear well before the onset of psychosis and have been reported to be present during early childhood and even during the first year of life. Taken together, these data raise the following question: Does the disease process that produces abnormalities in prefrontal GABA neurons in schizophrenia begin prenatally and disrupt the ontogeny of cortical GABA neurons? Here, we address this question through a consideration of evidence that genetic and/or environmental insults that occur during gestation initiate a pathogenetic process that alters cortical GABA neuron ontogeny and produces the pattern of GABA neuron abnormalities, and consequently cognitive difficulties, seen in schizophrenia. First, we review available evidence from postmortem human brain tissue studies characterizing alterations in certain subpopulations of prefrontal GABA neuron that provide clues to a prenatal origin in schizophrenia. Second, we review recent discoveries of transcription factors, cytokine receptors, and other developmental regulators that govern the birth, migration, specification, maturation, and survival of different subpopulations of prefrontal GABA neurons. Third, we discuss recent studies demonstrating altered expression of these ontogenetic factors in the PFC in schizophrenia. Fourth, we discuss the potential role of disturbances in the maternal-fetal environment such as maternal immune activation in the development of GABA neuron dysfunction. Finally, we propose critical questions that need to be answered in future research to further investigate the role of altered GABA neuron ontogeny in the pathogenesis of schizophrenia.

Determination of Neisseria gonorrhoeae susceptibility to ciprofloxacin in clinical specimens from men using a real-time PCR assay

A real-time PCR (RT-PCR) assay was modified to simultaneously detect Neisseria gonorrhoeae and to determine gonococcal susceptibility to ciprofloxacin using clinical samples. The modified RT-PCR assay was validated using DNA extracted from 40 linked isolates and urethral swabs, 24 of which had linked first-pass urine samples, obtained from men presenting with urethral gonorrhoea. The RT-PCR assay enabled amplification of N. gonorrhoeae dcmH, gyrA and parC genes. The quinolone resistance-determining regions (QRDRs) of the isolates' gyrA and parC genes were sequenced. Following successful validation, 33 first-pass urine-derived DNA extracts, obtained from men with gonorrhoea, were tested with the assay and results were compared with blinded ciprofloxacin susceptibility data. Gonococcal susceptibility to ciprofloxacin correlated perfectly with gyrA amplicon generation. No gyrA amplicons were detected for gonococcal infections due to ciprofloxacin-intermediate/resistant organisms. Amplification of parC correlated less well with ciprofloxacin susceptibility phenotypes. Simultaneous non-generation of gyrA and parC amplicons consistently predicted the presence of ciprofloxacin-resistant gonococci. Characteristic point mutations in the gyrA/parC QRDRs were found in DNA amplified from those extracts that failed to produce gyrA/parC amplicons. The RT-PCR assay performed well with DNA extracted from first-pass urine specimens and results correlated perfectly with ciprofloxacin susceptibility phenotypes. In conclusion, the modified RT-PCR assay can detect N. gonorrhoeae in DNA extracted from first-pass urine specimens of men with urethral gonorrhoea and accurately predicts gonococcal susceptibility to ciprofloxacin. This molecular assay provides a useful tool for surveillance and patient management in settings where fluoroquinolones can still be used for treatment of gonorrhoea.

Towards the bioequivalence of pressurised metered dose inhalers 2. Aerodynamically equivalent particles (with and without glycerol) exhibit different biopharmaceutical profiles in vitro

Two solution-based pressurised metered dose inhaler (pMDI) formulations were prepared such that they delivered aerosols with identical mass median aerodynamic diameters, but contained either beclomethasone dipropionate (BDP) alone (glycerol-free formulation) or BDP and glycerol in a 1:1 mass ratio (glycerol-containing formulation). The two formulations were deposited onto Calu-3 respiratory epithelial cell layers cultured at an air interface. Equivalent drug mass (∼1000ng or ∼2000ng of the formulation) or equivalent particle number (1000ng of BDP in the glycerol-containing versus 2000ng of BDP in the glycerol-free formulation) were deposited as aerosolised particles on the air interfaced surface of the cell layers. The transfer rate of BDP across the cell layer after deposition of the glycerol-free particles was proportional to the mass deposited. In comparison, the transfer of BDP from the glycerol-containing formulation was independent of the mass deposited, suggesting that the release of BDP is modified in the presence of glycerol. The rate of BDP transfer (and the extent of metabolism) over 2h was faster when delivered in glycerol-free particles, 465.01ng±95.12ng of the total drug (20.99±4.29%; BDP plus active metabolite) transported across the cell layer, compared to 116.17ng±3.07ng (6.07±0.16%) when the equivalent mass of BDP was deposited in glycerol-containing particles. These observations suggest that the presence of glycerol in the maturated aerosol particles may influence the disposition of BDP in the lungs.

Risk factors for venous thromboembolism in patients with chronic liver disease

BACKGROUND

Pharmacologic prophylaxis for venous thromboembolism (VTE) in patients with chronic liver disease (CLD) presents a unique challenge because of coagulopathies associated with the disease. When evaluating whether these patients require VTE prophylaxis upon hospitalization, it would be advantageous if risk factors for the development of VTE in this population were known.

OBJECTIVE

To evaluate risk factors associated with the development of VTE in patients with CLD.

METHODS

A retrospective case-control study was conducted. Patients admitted to the University of Kentucky Chandler Hospital from October 2006 to July 2010 with a diagnosis of CLD and VTE were matched in a 1:3 fashion with CLD patients without VTE. The primary objective was to determine whether there were significant differences in laboratory values between the 2 groups.

RESULTS

During this time, 27 patients with CLD (1.0%) were diagnosed with VTE. These patients had significantly lower median aspartate aminotransferase (AST) (47 vs 70 U/L, p = 0.04), alanine transaminase (ALT) (24.5 vs 36 U/L, p = 0.02), albumin (2.1 vs 2.4 g/dL, p = 0.02) and hematocrit (Hct) (28.3% vs 32%, p = 0.03) values compared to the control patients. Patients with albumin lower than 1.9 g/dL had a 5.1 times greater risk of VTE compared to patients with albumin of 2.8 g/dL and higher (OR 5.14, 95% CI 1.05-25.2).

CONCLUSIONS

Patients with CLD who developed VTE had significantly lower AST, ALT, albumin, and Hct compared to those of control patients. Studies are necessary to further examine the significance of this finding.

Proteomic analysis of aneurysm healing mechanism after coil embolization: comparison of dense packing with loose packing

BACKGROUND AND PURPOSE

In clinical practice, durability of occlusion following coil embolization is superior in densely packed, compared with loosely packed, aneurysms. In a rabbit model, we probed, by using proteomics tools, the biologic mechanisms associated with densely packed and completely occluded aneurysms, compared with loosely packed and incompletely occluded aneurysms, to explore the biologic mechanisms of intra-aneurysmal healing following embolization.

MATERIALS AND METHODS

Elastase-induced, saccular aneurysms were created in 24 rabbits. Aneurysms were allowed to mature, after which aneurysms were either densely (packing attenuation >25%) or loosely (packing attenuation <20%) packed with platinum coils by endovascular means. After 2 weeks (n = 6 for both groups) and 4 weeks (n = 6 for both groups) of implantation, aneurysm samples harboring coils were harvested. Soluble proteins were extracted from the necks and domes of aneurysms, and proteins were studied using proteomics and bioinformatics tools.

RESULTS

In dome tissue, 128 proteins at 2 weeks, and 8 proteins at 4 weeks, were differentially expressed in densely packed, compared with loosely packed, aneurysms. In the neck tissue, 2 proteins at 4 weeks were differentially expressed in densely packed aneurysms. Specific pathway analysis revealed that compared with loosely packed aneurysms, densely packed aneurysms were associated with up-regulation of cell-to-cell signaling and cell adhesion at 2 weeks. Conversely, at 4 weeks, densely packed aneurysms showed a decrease in the expression of structural proteins compared with loosely packed aneurysms.

CONCLUSIONS

These findings may focus efforts on specific targets aimed at improving the long-term healing of intracranial, saccular aneurysms.

Dendritic spine pathology in schizophrenia

Schizophrenia is a neurodevelopmental disorder whose clinical features include impairments in perception, cognition and motivation. These impairments reflect alterations in neuronal circuitry within and across multiple brain regions that are due, at least in part, to deficits in dendritic spines, the site of most excitatory synaptic connections. Dendritic spine alterations have been identified in multiple brain regions in schizophrenia, but are best characterized in layer 3 of the neocortex, where pyramidal cell spine density is lower. These spine deficits appear to arise during development, and thus are likely the result of disturbances in the molecular mechanisms that underlie spine formation, pruning, and/or maintenance. Each of these mechanisms may provide insight into novel therapeutic targets for preventing or repairing the alterations in neural circuitry that mediate the debilitating symptoms of schizophrenia.

Electrophysiological classes of layer 2/3 pyramidal cells in monkey prefrontal cortex

The activity of supragranular pyramidal neurons in the dorsolateral prefrontal cortex (DLPFC) neurons is hypothesized to be a key contributor to the cellular basis of working memory in primates. Therefore, the intrinsic membrane properties, a crucial determinant of a neuron's functional properties, are important for the role of DLPFC pyramidal neurons in working memory. The present study aimed to investigate the biophysical properties of pyramidal cells in layer 2/3 of monkey DLPFC to create an unbiased electrophysiological classification of these cells. Whole cell voltage recordings in the slice preparation were performed in 77 pyramidal cells, and 24 electrophysiological measures of their passive and active intrinsic membrane properties were analyzed. Based on the results of cluster analysis of 16 independent electrophysiological variables, 4 distinct electrophysiological classes of monkey pyramidal cells were determined. Two classes contain regular-spiking neurons with low and high excitability and constitute 52% of the pyramidal cells sampled. These subclasses of regular-spiking neurons mostly differ in their input resistance, minimum current that evoked firing, and current-to-frequency transduction properties. A third class of pyramidal cells includes low-threshold spiking cells (17%), which fire a burst of three-five spikes followed by regular firing at all suprathreshold current intensities. The last class consists of cells with an intermediate firing pattern (31%). These cells have two modes of firing response, regular spiking and bursting discharge, depending on the strength of stimulation and resting membrane potential. Our results show that diversity in the functional properties of DLPFC pyramidal cells may contribute to heterogeneous modes of information processing during working memory and other cognitive operations that engage the activity of cortical circuits in the superficial layers of the DLPFC.

Preventing the harm of a closer look: contrast-induced nephropathy in adults

Contrast media is administered to many patients in hospitals nationwide. Although the use of contrast and dyes is widespread and has a well accepted use among the medical profession, contrast-induced nephropathy can be a common and potentially harmful complication. Identifying patients at risk, attempting to minimize risk, and using preventative strategies should be priorities to decrease the harmful effects that are associated with the administration of contrast media. This article provides a general overview of contrast-induced nephropathy and a brief review of the risk factors and prophylactic treatment.

Killer-cell immunoglobulin-like receptor genotyping and HLA killer-cell immunoglobulin-like receptor-ligand identification by real-time polymerase chain reaction

The effector function of natural killer (NK) cells is modulated by surface expression of a range of killer-cell immunoglobulin-like receptors (KIRs) that interact with human leukocyte antigen (HLA) class I ligands. We describe the use of real-time polymerase chain reaction (PCR) assays that allow easy and quick detection of 16 KIR genes and the presence/absence of KIR-ligands based on allelic discrimination at codon 80 in the HLA-A/B Bw4 and HLA-C C1/C2 genes. These methods overcome the tedious and expensive nature of conventional KIR genotyping and HLA class I typing using sequence-specific primer (SSP) PCR, sequence-specific oligonucleotide (SSO) hybridization or sequence-based typing (SBT). Using these two cost-effective assays, we measured the frequencies of KIRs, KIR-ligands and KIR/KIR-ligand pairs in a cohort of Black women recruited in South Africa.

Patency of branches after coverage with multiple telescoping flow-diverter devices: an in vivo study in rabbits

BACKGROUND AND PURPOSE

The safety of placing multiple overlapped endoluminal flow diverters remains unclear because small eloquent branch arteries theoretically could become occluded by these devices. We placed single and multiple flow diverters over small branch arteries in rabbit aortas to determine the incidence of branch artery occlusion.

MATERIALS AND METHODS

Flow diverters (PED) were placed into 22 female New Zealand white rabbits abdominal aortas to cover ≥1 lumbar artery. Animals were divided into 3 groups (single PED, n = 9; double PED with 2 telescoped/overlapped devices, n = 7; and triple PED, with 3 telescoped/overlapped devices, n = 6) and were followed for 6 or 12 months. DSA was performed at follow-up. Subsequently, the tissue was processed, sectioned, and stained with H&E for histologic evaluation, histomorphometry, and analysis.

RESULTS

All the lumbar arteries covered by devices were clearly patent on angiography. Partial neointima covered the ostia of the branch vessels, but demonstrable patent lumens at the ostia in all cases were present. Neointima hyperplasia was minimal in the single-PED-group animals. The measured neointima was thicker for the double- and triple-PED groups compared with the single-PED group (P < .05). However, in all groups, the mean thickness of the neointima was ≤0.2 mm, and the percentage stenosis of the parent artery was <15% and 18% for 6 and 12 months, respectively. There was no significant inflammatory response in any group.

CONCLUSIONS

Small branch arteries remain patent even when covered by multiple overlapped PED flow-diverter devices.

The use of albumin microspheres in the treatment of carrageenan-induced inflammation in the rat

Free hydrocortisone, hydrocortisone incorporated into microspheres and empty microspheres have been administered orally to rats with carrageenan-induced hindpaw inflammation. Hydrocortisone administered in particles was effective at a lower dose than free steroid in reducing inflammation. Inflammatory exudates were able to release steroid from the microspheres by proteolytic degradation.

The Woven EndoBridge: a new aneurysm occlusion device

BACKGROUND AND PURPOSE

The WEB device is an intrasaccular ellipsoid braided-wire embolization device designed to provide flow disruption along the aneurysm neck. The purpose of this study was to evaluate, in an in vivo aneurysm model, the acute and chronic performance of the WEB device regarding immediacy, degree, and durability of aneurysm occlusion.

MATERIALS AND METHODS

The WEB device was implanted in 24 elastase-induced aneurysms in New Zealand white rabbits and followed for 1, 3, 6, and 12 months (n = 6 at all time points). Degree of intra-aneurysmal flow disruption was graded on a 4-point scale based on DSA within 10 minutes following device implantation. Chronic aneurysm occlusion was rated by using a 3-point scale. All aneurysms were harvested for histologic analysis.

RESULTS

Immediate postimplant grade 1 (complete flow cessation) was noted in 7 (29%) of 24 cases. Grade 2 (near-complete flow cessation) was noted in 13 (54%) of 24 cases. At follow-up, complete occlusion was noted in 8 (33%) of 24 cases. Near-complete aneurysm occlusion was noted in 14 (58%) of 24 cases, while incomplete occlusion was noted in 2 (8%) cases. Stable aneurysm occlusion was present in 7 (29%) of 24 cases; progressive occlusion, in 14 (58%); and recanalization, in 3 (13%) cases. Histologic findings included aneurysm cavities filled with organized thrombus with connective tissue across the aneurysm neck.

CONCLUSIONS

The WEB device in experimental aneurysms demonstrated promising rates of immediate and long-term aneurysm occlusion.

A clinical-laboratory algorithm incorporating optical density value to predict heparin-induced thrombocytopenia

The diagnosis of heparin-induced thrombocytopenia (HIT) is complex and involves integrating both clinical and laboratory findings. Readily available diagnostic tests such as the heparin-dependant antibody assay (HDAA) lack desired specificity when utilised alone. A diagnostic algorithm incorporating the 4T pretest probability score, HDAA, and optical density (OD) value was implemented as a tool to assist in the diagnosis of HIT and with the decision to treat patients. Patients with a 4T score >3 and/or positive HDAA result with an OD ≥1 were considered positive. Utilisation of this algorithm was hypothesised to improve the identification of patients without SRA confirmed HIT and improve overall specificity compared to other diagnostic strategies. Retrospective chart review was conducted and included patients with a positive or equivocal HDAA result and a serotonin release assay result during a two-year period. Each patient was evaluated for the diagnosis of HIT using the algorithm. The specificity and sensitivity of the diagnostic algorithm to identify subjects with SRA confirmed HIT was evaluated. A total of 83 patients were identified for inclusion in the study. The diagnostic algorithm identified 22 patients for direct thrombin inhibitor (DTI) therapy. Nine of these patients were SRA positive. The sensitivity of the algorithm was 0.9 with a specificity of 0.822. The diagnostic algorithm was found to be both more specific and sensitive than other diagnostic strategies including the 4T score alone, HDAA alone, and the combination of the 4T score and HDAA results. This preliminary data suggest a diagnostic algorithm combining 4T score, HDAA, and OD value may be a tool to aid in the identification SRA positive patients for DTI therapy.

Acquisition and baseline performance of working memory tasks by adolescent rhesus monkeys

Adolescence is a transitional stage of development characterized by protracted refinements in the neural circuits required for adult level proficiency of working memory. Because impaired working memory is a hallmark feature of several psychiatric disorders that have their onset during adolescence, model systems that can be used to assess the maturation of working memory function, and of disease-related risk factors that disrupt its development, are of particular importance. However, few studies have investigated the maturation of working memory in nonhuman primates. Thus in the present study, we adapted two working memory tests that are among the most widely used in human and adult nonhuman primates, for adolescent rhesus monkeys. Using a touch-screen apparatus, monkeys were trained on a spatial delayed-response task to assess spatial working memory and a delayed match-to-sample task to assess object working memory. The results indicate that adolescent rhesus monkeys readily and efficiently acquire the ability to perform touch-screen based, complex tests of working memory. These data establish that distinct components of adult prefrontal cortex-dependent cognitive functions can be effectively modeled and evaluated in adolescent monkeys. As such, this approach should be useful for assessing the influence of environmental risk factors on the protracted maturation of working memory in adolescent macaques.

Preliminary results of the luna aneurysm embolization system in a rabbit model: a new intrasaccular aneurysm occlusion device

BACKGROUND AND PURPOSE

Recent advances in endovascular devices have been aimed at providing high density, mesh-like metallic materials across the aneurysm neck, in place of coil technology. Therefore our aim was to report the in vivo preclinical performance of a self-expanding intrasaccular embolization device.

MATERIALS AND METHODS

Elastase-induced aneurysms were created in 12 rabbits. Each aneurysm was embolized with a Luna AES. DSA was performed preimplantation; 5, 10, and 30 minutes postimplantation; and at 1 month in 12 rabbits and at 3 months in 8 rabbits. Early postimplantation intra-aneurysmal flow was graded as unchanged, moderately diminished, or completely absent. One- and 3-month DSAs were graded by using a 3-point scale (complete, near-complete, or incomplete occlusion). Aneurysms were harvested for gross and microscopic histologic evaluation at 1 month (n = 4) and at 3 months (n = 8). Tissues within the aneurysm dome and across the aneurysm neck were assessed by using HE staining.

RESULTS

Ten (83%) of 12 aneurysms demonstrated complete cessation of flow within 30 minutes of device implantation. At 1-month follow-up, 10 (83%) of 12 aneurysms were completely occluded. At 3 months, 7 of 8 (88%) aneurysms remained completely occluded. One-month gross examination in 4 rabbits demonstrated that membranous tissue completely covered the device in 3 subjects (75%). Microscopic examination showed that 3 aneurysms had loose connective tissue filling the aneurysm cavity. Three-month gross and microscopic examinations demonstrated membranous tissue completely covering the device, loose connective tissue filling the aneurysm cavity, and neointima formation crossing the aneurysm neck in 8 of 8 (100.0%) subjects.

CONCLUSIONS

The Luna AES achieved high rates of complete angiographic occlusion and showed promising histologic findings in the rabbit aneurysm model.

Glimepiride-Induced Hypoglycemia with Ciprofloxacin, Metronidazole, and Acute Kidney Injury

A 79-year-old white male presented to the emergency room with altered mental status and a blood glucose of 28 mg/dL. He was taking glimepiride 1 mg by mouth daily prior to admission and had recently been prescribed ciprofloxacin and metronidazole for diverticulitis. The patient was also found to have acute-on-chronic renal failure upon presentation. Escalated dextrose infusion with repeated doses of D50W and glucagon failed to sustain his blood glucose, which remained in the range of 30 to 50 mg/dL. Salvage treatment with intravenous octreotide was implemented successfully; only one dose of D50W was required after octreotide initiation and blood glucose normalized within several hours. In the presence of this patient's complex medication therapy, we explore the contributing causes of hypoglycemia. Fluoroquinolones are widely associated with dysglycemias, particularly in diabetic patients receiving hypoglycemic agents. Similarly, renal insufficiency has been implicated to precipitate hypoglycemia with sulfonylureas, with dosage adjustment being required almost class-wide. We also recognize a theoretical drug interaction mediated by metronidazole-induced CYP 2C9 inhibition of glimepiride metabolism. Sulfonylurea-induced hypoglycemia can be serious and refractory to traditional therapy and can be exacerbated by multiple factors, such as drug interactions or impaired renal function. In the era of complex medication therapy for patient populations with multiple disease states, we present a severe episode of glimepiride-induced hypoglycemia with multiple causative factors.

Creation of large elastase-induced aneurysms: presurgical arterial remodeling using arteriovenous fistulas

BACKGROUND AND PURPOSE

The size of elastase-induced aneurysms created in the usual way is relatively small. Our aim was to determine whether creation of a carotid-jugular AVF to induce remodeling of the RCCA results in larger elastase-induced aneurysms in rabbits.

MATERIALS AND METHODS

RCCA right-jugular AVFs were created in 6 New Zealand white rabbits (group 1), followed by elastase-induced aneurysm creation 4 weeks later. Follow-up DSA was performed to assess AVF patency and aneurysm sizes. Six other elastase-induced aneurysms created in the usual way were used as controls (group 2). The diameters of the RCCA and LCCA in group 1 and aneurysm sizes in both groups were measured from DSA images and compared by using the Student t test.

RESULTS

The patency of AVFs in group 1 was confirmed in all 6 (100%) cases. The mean RCCA diameter in group 1 was larger than that in the contralateral LCCA (3.6 ± 0.7 mm versus 2.0 ± 0.1 mm, range, 1.8-2.2 mm, P < .01). The mean aneurysm neck diameter, width, and height for group 1 was larger than those of group 2 (4.6 ± 0.9 mm versus 3.5 ± 0.7 mm, P < .05; 4.7 ± 1.1 mm versus 3.4 ± 0.5 mm, P < .05; 13.8 ± 3.2 mm versus 8.1 ± 1.3 mm, P < .05, respectively). Aneurysm volume for group 1 was significantly larger than that of group 2 (273 ± 172 mm³ versus 77 ± 32 mm³, P < .05).

CONCLUSIONS

Carotid-jugular AVFs result in RCCA remodeling that yields relatively larger elastase-induced aneurysms.

Acute HIV infections among men with genital ulcer disease in South Africa

We investigated acute human immunodeficiency virus (HIV) infection among men enrolled in a genital ulcer treatment trial in South Africa. HIV-negative participants were tested at baseline by HIV RNA polymerase chain reaction and followed up after 1 month to measure HIV seroconversion. There were 228 HIV-negative men at baseline; 10 were positive for HIV RNA, and 8 seroconverted to HIV at day 28. The prevalence of acute HIV among HIV-negative men at baseline was 18 (7.9%) of 228 men (95% confidence interval [CI], 4.4-11.4) and 18 (2.9%) of 615 men (95% CI, 1.6-4.3) in the overall study population. These data highlight the importance of genital ulcer patients in HIV transmission. Trial Registration. ClinicalTrials.gov identifier: NCT00164424 .

Five-year follow-up in elastase-induced aneurysms in rabbits

BACKGROUND AND PURPOSE

There is no report regarding patency of elastase-induced aneurysms for more than a 2-year period. Our aim was to report aneurysm patency rates up to 5 years in the elastase-induced aneurysm model in rabbits.

MATERIALS AND METHODS

Twenty-five elastase-induced aneurysms were created in New Zealand white rabbits and followed for up to 5 years. Thirteen (52%) rabbits died during follow-up for reasons unrelated to the aneurysms. DSA was performed at 1 month and at 2 and 5 years in the 12 surviving subjects. Aneurysm patency and dimensions, including neck diameter and aneurysm width and height, were evaluated at each time point in relation to external sizing devices. Differences of aneurysm sizes (neck width and aneurysm width and height) among time points were compared by using the Student t test.

RESULTS

Eleven (92%) of the 12 aneurysms in the subjects that survived for 5 years remained fully patent throughout follow-up. A single narrow-neck aneurysm showed partial thrombosis at the 2- and 5-year time points.

CONCLUSIONS

Experimental elastase-induced aneurysms in rabbits demonstrate high rates of patency up to 5 years following creation. When planning for very long-term studies, investigators should plan for relatively high rates of mortality unrelated to aneurysm pathology.