In Vivo Cerebral Imaging of Mutant Huntingtin Aggregates Using 11C-CHDI-180R PET in a Nonhuman Primate Model of Huntington Disease

Huntington disease (HD) is a neurodegenerative disorder caused by an expanded polyglutamine (CAG) trinucleotide expansion in the huntingtin (HTT) gene that encodes the mutant huntingtin protein (mHTT). Visualization and quantification of cerebral mHTT will provide a proxy for target engagement and a means to evaluate therapeutic interventions aimed at lowering mHTT in the brain. Here, we validated the novel radioligand 11C-labeled 6-(5-((5-methoxypyridin-2-yl)methoxy)benzo[d]oxazol-2-yl)-2-methylpyridazin-3(2H)-one (11C-CHDI-180R) using PET imaging to quantify cerebral mHTT aggregates in a macaque model of HD. Methods: Rhesus macaques received MRI-guided intrastriatal delivery of a mixture of AAV2 and AAV2.retro viral vectors expressing an HTT fragment bearing 85 CAG repeats (85Q, n = 5), a control HTT fragment bearing 10 CAG repeats (10Q, n = 4), or vector diluent only (phosphate-buffered saline, n = 5). Thirty months after surgery, 90-min dynamic PET/CT imaging was used to investigate 11C-CHDI-180R brain kinetics, along with serial blood sampling to measure input function and stability of the radioligand. The total volume of distribution was calculated using a 2-tissue-compartment model as well as Logan graphical analysis for regional quantification. Immunostaining for mHTT was performed to corroborate the in vivo findings. Results: 11C-CHDI-180R displayed good metabolic stability (51.4% ± 4.0% parent in plasma at 60 min after injection). Regional time-activity curves displayed rapid uptake and reversible binding, which were described by a 2-tissue-compartment model. Logan graphical analysis was associated with the 2-tissue-compartment model (r 2 = 0.96, P < 0.0001) and used to generate parametric volume of distribution maps. Compared with controls, animals administered the 85Q fragment exhibited significantly increased 11C-CHDI-180R binding in several cortical and subcortical brain regions (group effect, P < 0.0001). No difference in 11C-CHDI-180R binding was observed between buffer and 10Q animals. The presence of mHTT aggregates in the 85Q animals was confirmed histologically. Conclusion: We validated 11C-CHDI-180R as a radioligand to visualize and quantify mHTT aggregated species in a HD macaque model. These findings corroborate our previous work in rodent HD models and show that 11C-CHDI-180R is a promising tool to assess the mHTT aggregate load and the efficacy of therapeutic strategies.

Terumo spectra optia leukapheresis of cynomolgus macaques for hematopoietic stem cell and T cell collection

Macaques are physiologically relevant animal models of human immunology and infectious disease that have provided key insights and advanced clinical treatment in transplantation, vaccinology, and HIV/AIDS. However, the small size of macaques is a stumbling block for studies requiring large numbers of cells, such as hematopoietic stem cells (HSCs) for transplantation, antigen-specific lymphocytes for in-depth immunological analysis, and latently-infected CD4+ T-cells for HIV cure studies. Here, we provide a detailed protocol for collection of large numbers of HSCs and T-cells from cynomolgus macaques as small as 3 kg using the Terumo Spectra Optia apheresis system, yielding an average of 5.0 × 10⁹ total nucleated cells from mobilized animals and 1.2 × 10⁹ total nucleated cells from nonmobilized animals per procedure. This report provides sufficient detail to adapt this apheresis technique at other institutions, which will facilitate more efficient and detailed analysis of HSCs and their progeny blood cells.

Longitudinal analysis of atherosclerotic cardiovascular disease risk and healthcare costs in newly diagnosed type 2 diabetes in a real-world setting

AIMS

To assess longitudinal risk for atherosclerotic cardiovascular disease (ASCVD) and cost of healthcare resource utilization over 9 years in patients with or without newly diagnosed type 2 diabetes (T2DM) who had no ASCVD at baseline.

METHODS

This retrospective, longitudinal analysis of a large, nationwide US administrative claims database compared adults with newly diagnosed T2DM (n = 22,468) and a propensity score matched non-T2DM cohort (n = 22,468). Longitudinal risk of ASCVD and total annual healthcare costs were determined. Subgroup analysis was conducted for 3 age categories: 18-44, 45-64, and 65+ years.

RESULTS

From 2006 to 2015, ASCVD was identified in a significantly greater percentage of patients in the T2DM versus non-T2DM cohort (43.2% vs 32.3%; Hazard ratio [HR] = 1.45, P < 0.001). Total annual healthcare cost was markedly higher in T2DM versus non-T2DM cohorts (48.4% higher at year 9). The differences between cohorts were most pronounced in patients aged 18-44 years.

CONCLUSIONS

This 9-year claims-based retrospective, longitudinal analysis showed a higher risk of ASCVD and higher healthcare costs in newly diagnosed T2DM patients versus those without T2DM, with highest relative risk and cost differences observed in younger patients.

Trends in comorbidity burden and treatment patterns in type 2 diabetes: Longitudinal data from a US cohort from 2006 to 2014

AIMS

To gather real-world data on treatment characteristics and comorbidity progression in patients with newly-diagnosed type 2 diabetes (T2D) and evaluate differences by patient age.

METHODS

Retrospective analysis of a US administrative claims database including 16,950 subjects with newly-diagnosed T2D in 2006 and a baseline Diabetes Complications Severity Index (DCSI) score of 0. Patients were categorized by DCSI score at year 8 (0, 1-2, or ≥3) and comparatively analyzed based on demographic variables, drug usage, and diabetes-related comorbidities.

RESULTS

Year 8 DCSI score distribution was 0 (29.9%), 1-2 (36.2%), and ≥3 (33.9%). The highest DCSI score subgroup (≥3) was characterized by a significantly greater percentage of males, older age at T2D diagnosis, and higher Medicare enrollment. DCSI progressed most rapidly in the oldest age group (≥65). Among all subjects at year 8, insulin use was significantly highest among subjects with DCSI ≥3 compared with those having a lower DCSI. However, for subjects with DCSI ≥3, insulin use was lower among those in the oldest age group (≥65) relative to younger age groups.

CONCLUSIONS

These real-world data suggest a relationship between age at T2D diagnosis and disease progression based on comorbidity burden and lower usage of injectable therapies in older patients.

Allogeneic stem cell transplantation in fully MHC-matched Mauritian cynomolgus macaques recapitulates diverse human clinical outcomes

Allogeneic hematopoietic stem cell transplantation (HSCT) is a critically important therapy for hematological malignancies, inborn errors of metabolism, and immunodeficiency disorders, yet complications such as graft-vs.-host disease (GvHD) limit survival. Development of anti-GvHD therapies that do not adversely affect susceptibility to infection or graft-vs.-tumor immunity are hampered by the lack of a physiologically relevant, preclinical model of allogeneic HSCT. Here we show a spectrum of diverse clinical HSCT outcomes including primary and secondary graft failure, lethal GvHD, and stable, disease-free full donor engraftment using reduced intensity conditioning and mobilized peripheral blood HSCT in unrelated, fully MHC-matched Mauritian-origin cynomolgus macaques. Anti-GvHD prophylaxis of tacrolimus, post-transplant cyclophosphamide, and CD28 blockade induces multi-lineage, full donor chimerism and recipient-specific tolerance while maintaining pathogen-specific immunity. These results establish a new preclinical allogeneic HSCT model for evaluation of GvHD prophylaxis and next-generation HSCT-mediated therapies for solid organ tolerance, cure of non-malignant hematological disease, and HIV reservoir clearance.

Rhesus macaques are not ideal for studying response to allogeneic hematopoietic stem cell transplant (allo-HSCT) owing to complex MHC genetics that prevent full MHC-matching. Here the authors show that inbred Mauritian-origin cynomolgus macaques are a superior preclinical model of allogeneic stem cell transplantation that mimics diverse clinical outcomes of human allo-HSCT.

Drug usage patterns and treatment costs in newly-diagnosed type 2 diabetes mellitus cases, 2007 vs 2012: findings from a large US healthcare claims database analysis

Objective To explore trends in demographics, comorbidities, anti-diabetic drug usage, and healthcare utilization costs in patients with newly-diagnosed type 2 diabetes mellitus (T2DM) using a large US claims database. Methods For the years 2007 and 2012, Truven Health Marketscan Research Databases were used to identify adults with newly-diagnosed T2DM and continuous 12-month enrollment with prescription benefits. Variables examined included patient demographics, comorbidities, inpatient utilization patterns, healthcare costs (inpatient and outpatient), drug costs, and diabetes drug claim patterns. Results Despite an increase in the overall database population between 2007-2012, the incidence of newly-diagnosed T2DM decreased from 1.1% (2007) to 0.65% (2012). Hyperlipidemia and hypertension were the most common comorbidities and increased in prevalence from 2007 to 2012. In 2007, 48.3% of newly-diagnosed T2DM patients had no claims for diabetes medications, compared with 36.2% of patients in 2012. The use of a single oral anti-diabetic drug (OAD) was the most common diabetes medication-related claim (46.2% of patients in 2007; 56.7% of patients in 2012). Among OAD monotherapy users, metformin was the most commonly used and increased from 2007 (74.7% of OAD monotherapy users) to 2012 (90.8%). Decreases were observed for sulfonylureas (14.1% to 6.2%) and thiazolidinediones (7.3% to 0.6%). Insulin, predominantly basal insulin, was used by 3.9% of patients in 2007 and 5.3% of patients in 2012. Mean total annual healthcare costs increased from $13,744 in 2007 to $15,175 in 2012, driven largely by outpatient services, although costs in all individual categories of healthcare services (inpatient and outpatient) increased. Conversely, total drug costs per patient were lower in 2012 compared with 2007. Conclusions Despite a drop in the rate of newly-diagnosed T2DM from 2007 to 2012 in the US, increased total medical costs and comorbidities per individual patient suggest that the clinical and economic trends for T2DM are not declining.

Preclinical safety of RNAi-mediated HTT suppression in the rhesus macaque as a potential therapy for Huntington's disease

To date, a therapy for Huntington's disease (HD), a genetic, neurodegenerative disorder, remains elusive. HD is characterized by cell loss in the basal ganglia, with particular damage to the putamen, an area of the brain responsible for initiating and refining motor movements. Consequently, patients exhibit a hyperkinetic movement disorder. RNA interference (RNAi) offers therapeutic potential for this disorder by reducing the expression of HTT, the disease-causing gene. We have previously demonstrated that partial suppression of both wild-type and mutant HTT in the striatum prevents behavioral and neuropathological abnormalities in rodent models of HD. However, given the role of HTT in various cellular processes, it remains unknown whether a partial suppression of both alleles will be safe in mammals whose neurophysiology, basal ganglia anatomy, and behavioral repertoire more closely resembles that of a human. Here, we investigate whether a partial reduction of HTT in the normal non-human primate putamen is safe. We demonstrate that a 45% reduction of rhesus HTT expression in the mid- and caudal putamen does not induce motor deficits, neuronal degeneration, astrogliosis, or an immune response. Together, these data suggest that partial suppression of wild-type HTT expression is well tolerated in the primate putamen and further supports RNAi as a therapy for HD.

Ovarian surface epitheliectomy in the non-human primate: continued cyclic ovarian function and limited epithelial replacement

BACKGROUND

The fifth leading cause of cancer deaths among women is ovarian cancer (OC), which originates primarily in the ovarian surface epithelium (OSE) that surrounds the ovary. Permanent removal of the OSE could provide a novel strategy to substantially reduce OC risk, while retaining the benefits of ovarian function, including gameto- and steroidogenesis. It must be determined whether ovarian surface epitheliectomy (OSEx) carries deleterious side effects, including loss of menstrual cyclicity, infertility or scarring (e.g. adhesions), prior to any clinical application of this strategy. To achieve this, we selected the non-human primate, rhesus macaque, for long-term (12 month) studies on the effects of OSEx.

METHODS

Rhesus macaque females underwent OSEx by detergent treatment and were then monitored for menstrual cyclicity (menstruation, steroidogenesis and follicle development) and adverse side effects (tissue scarring or adhesions). Ovaries were collected at 6 or 12 months and examined for evidence of tissue damage, follicle rupture and regression of the corpus luteum. The ovarian surface was examined immunohistologically for signs of epithelial replacement, using markers for OSE and fimbrial epithelium (FE), a possible alternative source of pelvic tumors diagnosed as OC.

RESULTS

After OSEx, menstrual cycle length, estrogen and progesterone production, follicle rupture and luteal regression appeared normal. No evidence of adhesions was seen. At 6 and 12 months post-OSEx, the ovarian surface was sparsely populated by cells expressing OSE and FE markers. Proliferative activity in this population was notably low.

CONCLUSIONS

OSEx may provide a novel method to reduce the risk of OC, without sacrificing ovarian function, although the effects on fertility remain to be tested. The absence of epithelial replacement via enhanced proliferation suggests OSEx does not increase malignant potential. Complete and permanent OSEx may be feasible.

Loss of naive T cells and repertoire constriction predict poor response to vaccination in old primates

Aging is usually accompanied by diminished immune protection upon infection or vaccination. Although aging results in well-characterized changes in the T cell compartment of long-lived, outbred, and pathogen-exposed organisms, their relevance for primary Ag responses remain unclear. Therefore, it remains unclear whether and to what extent the loss of naive T cells, their partial replacement by oligoclonal memory populations, and the consequent constriction of TCR repertoire limit the Ag responses in aging primates. We show in this study that aging rhesus monkeys (Macaca mulatta) exhibit poor CD8 T cell and B cell responses in the blood and poor CD8 responses in the lungs upon vaccination with the modified vaccinia strain Ankara. The function of APCs appeared to be maintained in aging monkeys, suggesting that the poor response was likely intrinsic to lymphocytes. We found that the loss of naive CD4 and CD8 T cells, and the appearance of persisting T cell clonal expansions predicted poor CD8 responses in individual monkeys. There was strong correlation between early CD8 responses in the transitory CD28+ CD62L- CD8+ T cell compartment and the peak Ab titers upon boost in individual animals, as well as a correlation of both parameters of immune response to the frequency of naive CD8+ T cells in old but not in adult monkeys. Therefore, our results argue that T cell repertoire constriction and naive cell loss have prognostic value for global immune function in aging primates.

Ovulation in the absence of the ovarian surface epithelium in the primate

The ovarian surface epithelium (OSE) has a prominent role in ovarian cancer in women, but no studies have been conducted to evaluate its role in normal ovarian function. Data from other species suggest the OSE is needed for ovulation. We have tested whether the OSE is needed for follicle rupture, a necessary step in ovulation, using the nonhuman primate, rhesus macaque. The OSE was removed in two different short-term protocols spanning a single periovulatory interval--one protocol used a cytology brush to remove the OSE only from the follicle apex, and one used mild detergent to remove the entire OSE--and in one long-term protocol spanning 6 wk (two periovulatory intervals) that removed the entire OSE with detergent. Serum levels of estrogen and progesterone (E and P) were monitored, and sectioned ovaries were examined for evidence of successful OSE removal and follicle rupture. In the short-term protocols, removal of the OSE over the follicle apex did not prevent follicle rupture (n = 4 ovaries), but removal of the entire OSE using detergent did in four of six cases. In the long-term protocol, when ovaries were collected after the second periovulatory interval, all the ovaries (n = 5) showed evidence of follicle rupture. In all the protocols, E and P production appeared unaffected. Detergent penetrated up to 40 microm into the ovary. This may have transiently disrupted the stroma and caused follicle rupture failure. We conclude that the primate OSE is not essential for ovulation and perhaps can be removed without lasting consequence.

A collaborative approach to managing student malingering

The authors present a case study of a successful collaborative effort to reduce student malingering in a school-based health center and to address the academic and social problems related to overuse of center services. School-based health centers have been identified as important sources of support for teenagers who have emotional and psychological problems, and, in this case, the overuse of a school-based health center is linked to such challenges for a substantial subset of students. It demonstrates that it is possible to identify, based on their status as frequent center users, students with potentially serious academic, family, or personal problems who are at risk for academic failure. The case involves multiple professionals, from a variety of disciplines, who dealt successfully with the problems associated with overuse of center services.

Cellular dynamics of growth in sheep and goat synepitheliochorial placentomes: an autoradiographic study

This paper demonstrates that in sheep and goats the two definitive fetomaternal interface layers are developmentally related. The fetal trophectoderm consists of binucleate and uninucleate cells. The apical microvilli of the trophectoderm interdigitate with a layer consisting of syncytial plaques of limited area bounding the maternal connective tissue. Our previous histological ultrastructural and immunocytochemical work has indicated that throughout pregnancy the fetal binucleate cells migrate to and fuse with the uterine epithelium or its derivatives to form these syncytial plaques which constitute a persistent fetomaternal tissue unique to ruminants. This quantitative autoradiographic study of thymidine incorporation into sheep and goat placentas confirms the central role of the binucleate cell in placental growth, demonstrates that throughout pregnancy all binucleate cells migrate and indicates that most of the nuclei of the syncytial plaques, which appear to have a limited lifespan, derive from binucleate cell fusion.

The efficacy and safety of auranofin compared to placebo in rheumatoid arthritis

This double-blind multicenter study compares the effect of adding auranofin (AF) 3 mg bid or placebo to patients already taking nonsteroidal antiinflammatory drugs for rheumatoid arthritis. The 242 patients who completed 3 months of therapy demonstrated that the group receiving AF responded better than those receiving placebo. Of the 144 patients who completed 6 months coded medication, the efficacy in the AF group was superior to the placebo group in several parameters including a reduction in the number of painful or swollen joints, grip strength, dropout rate, and global efficacy as judged by the evaluating physician. A significant lowering of the Westergren erythrocyte sedimentation rate and immunoglobulin levels was noted in the AF treated patients. This study includes data summarizing the difference between both groups with respect to on-therapy conditions and toxicity.

Autoradiographic evidence for migration and fusion of cells in the sheep placenta: resolution of a problem in placental classification

The location of the fetomaternal junction in the placenta is important with respect to structural classification and the identification of any possible barrier to maternal immunorejection. Structural classification of the sheep placenta remains controversial on account of the uncertain origin of the syncytial layer. In this study [3H]thymidine was injected into the fetus and placentomes were removed between 4h and 21 days afterwards. Autoradiography showed that the syncytium is derived predominantly from the migration of fetal binucleate cells and not from the maternal uterine epithelium as most recent reports have suggested. In this respect the origin of the syncytium in the sheep placenta is similar to that reported in certain other eutherian mammals. The finding that cells originating from the fetal allograft survive after migration through the microvillous junction poses questions as to the mechanism by which the syncytial layer resists maternal immune rejection throughout gestation.