Ether Bond Cleavage of a Phenylcoumaran β-5 Lignin Model Compound and Polymeric Lignin Catalysed by a LigE-type Etherase from Agrobacterium sp

A LigE-type beta-etherase enzyme from lignin-degrading Agrobacterium sp. has been identified, which assists degradation of polymeric lignins. Testing against lignin dimer model compounds revealed that it does not catalyse the previously reported reaction of Sphingobium SYK-6 LigE, but instead shows activity for a β-5 phenylcoumaran lignin dimer. The reaction products did not contain glutathione, indicating a catalytic role for reduced glutathione in this enzyme. Three reaction products were identified: the major product was a cis-stilbene arising from C-C fragmentation involving loss of formaldehyde; two minor products were an alkene arising from elimination of glutathione, and an oxidised ketone, proposed to arise from reaction of an intermediate with molecular oxygen. Testing of the recombinant enzyme against a soda lignin revealed the formation of new signals by two-dimensional NMR analysis, whose chemical shifts are consistent with the formation of a stilbene unit in polymeric lignin.

Depletion of SAM leading to loss of heterochromatin drives muscle stem cell ageing

The global loss of heterochromatin during ageing has been observed in eukaryotes from yeast to humans, and this has been proposed as one of the causes of ageing. However, the cause of this age-associated loss of heterochromatin has remained enigmatic. Here we show that heterochromatin markers, including histone H3K9 di/tri-methylation and HP1, decrease with age in muscle stem cells (MuSCs) as a consequence of the depletion of the methyl donor S-adenosylmethionine (SAM). We find that restoration of intracellular SAM in aged MuSCs restores heterochromatin content to youthful levels and rejuvenates age-associated features, including DNA damage accumulation, increased cell death, and defective muscle regeneration. SAM is not only a methyl group donor for transmethylation, but it is also an aminopropyl donor for polyamine synthesis. Excessive consumption of SAM in polyamine synthesis may reduce its availability for transmethylation. Consistent with this premise, we observe that perturbation of increased polyamine synthesis by inhibiting spermidine synthase restores intracellular SAM content and heterochromatin formation, leading to improvements in aged MuSC function and regenerative capacity in male and female mice. Together, our studies demonstrate a direct causal link between polyamine metabolism and epigenetic dysregulation during murine MuSC ageing.

Structure-Based Design and Synthesis of Potent and Selective KRAS G12D Inhibitors

KRAS G12D mutation has been found in approximately 45% of pancreatic ductal adenocarcinoma (PDAC) cases, making it an attractive therapeutic target. Through structure-based drug design, a series of potent and selective KRAS G12D inhibitors were designed. The lead compound, ERAS-5024, inhibited ERK1/2 phosphorylation and cell proliferation in three-dimensional Cell-Titer Glo assays in AsPC-1 PDAC cells with single-digit nanomolar potency and caused tumor regression in the in vivo efficacy studies. We describe here the details of the design and synthesis program that led to the discovery of ERAS-5024.

The pharmacologic and toxicologic characterization of the potent and selective KRAS G12D inhibitors ERAS-4693 and ERAS-5024

Two potent and selective KRASG12D inhibitors, ERAS-4693 and ERAS-5024, were generated as possible clinical candidates to treat patients harboring G12D mutations in solid tumors. Both molecules exhibited strong anti-tumor activity in the KRASG12D mutant PDAC xenograft mouse models while ERAS-5024 also showed tumor growth inhibition when administered on an intermittent dosing regimen. Acute dose-limiting toxicity consistent with an allergic reaction was observed for both molecules shortly after administration at doses just above those which demonstrated anti-tumor activity, indicative of a narrow therapeutic index. A series of studies were subsequently conducted to identify a common underlying mechanism for the observed toxicity, including CETSA® (Cellular Thermal Shift Assay) as well as several functional off-target screens. Both ERAS-4693 and ERAS-5024 were identified to agonize MRGPRX2 which has been linked to pseudo-allergic reactions. In vivo toxicologic characterization of both molecules included repeat-dose studies in the rat and dog. Dose-limiting toxicities were observed in both species with ERAS-4693 and ERAS-5024 and plasma exposure levels at the maximum tolerated doses were generally below that which caused strong anti-tumor activity, supporting the initial observation of a narrow therapeutic index. Additional overlapping toxicities included a reduction in reticulocytes and clinical pathological changes suggestive of an inflammatory response. Furthermore, increases in plasma histamine were observed in dogs administered ERAS-5024, supporting the hypothesis that MRGPRX2 agonism may be the cause of the pseudo-allergic reaction. This work highlights the importance of balancing both the safety and efficacy of KRASG12D inhibitors as this class of molecules begins to enter clinical development.

Abstract 2675: Discovery of potent CNS-penetrant covalent KRAS G12C inhibitors

The RAS family of GTPases, which include KRAS, NRAS, and HRAS, are key regulators of cellular signaling, acting as molecular switches downstream of receptor tyrosine kinases (RTKs) and as key regulators of the RAS/MAPK pathway. RAS cycles between inactive (GDP) and active (GTP) states to regulate the activity of the RAS/MAPK pathway. In many cancers, activating KRAS mutations enable KRAS to persist in the active GTP-bound state, resulting in hyperactive RAS/MAPK pathway signaling that drives cell growth and survival. The KRAS G12C mutation occurs in 14% of lung adenocarcinoma, a cancer type that frequently metastasizes to the brain (40%). To address the high prevalence of KRAS G12C mutant CNS metastases in lung adenocarcinoma, we are developing CNS-penetrant covalent KRAS G12C inhibitors (“ERAS G12Ci’s”) to treat both CNS and systemic disease. ERAS G12Ci’s rapidly form covalent adducts with the KRAS G12C protein in its inactive GDP state and exhibit low nanomolar IC50’s in a nucleotide exchange assay. ERAS G12Ci’s demonstrate high selectivity in a cell-based proteome selectivity assay and inhibit the growth of RAS Initiative KRAS G12C mutant cells, and not RAS Initiative KRAS WT cells. ERAS G12Ci’s potently inhibit cell proliferation in 3-dimensional Cell-Titer Glo (3D-CTG) assays in KRAS G12C mutant lung and pancreatic cell lines (NCI-H1373, NCI-H2122, and MIA PaCa-2). Mechanistically, ERAS G12Ci’s blocked RAS-RAF complex formation and inhibited ERK1/2 phosphorylation. This in vitro activity translates in vivo where ERAS G12Ci’s induce pharmacodynamic modulation in the pancreatic cancer MIA PaCa-2 model. ERAS G12Ci’s significantly inhibit tumor growth in NCI-H1373 and NCI-H2122 CDX lung adenocarcinoma and MIA PaCa-2 PDAC models. No meaningful body weight loss or clinical adverse events were observed with any of these compounds. Human efflux transporter substrate assessments indicate that ERAS G12Ci’s are either not substrates or weak/modest substrates of P-gp, a crucial efflux transporter that can limit CNS penetration. In rat CNS studies, these inhibitors exhibit good CNS penetration performance as measured by brain-to-plasma partition coefficients, which are comparable to those of approved CNS-active small molecule inhibitors. Daily oral administration demonstrates dose-dependent tumor regression in intracranial and intra-carotid injection (ICA) KRAS G12C CDX models. We are optimizing multiple covalent CNS-penetrant KRAS G12C inhibitors that exhibit both CNS and systemic activity in vivo.

Citation Format: Jae Hyun Bae, Erin D. Lew, Jun Feng, Marcos Gonzalez-Lopez, Joanne Oh, Patrick Fagan, Matt Salie, Nick Isley, Richard Lam, Adriana Irimia, Robin Nevarez, Bingzhen Lin, Taylor Congdon, Jingchuan Zhang, Dawei Xuan, Ping Chen, Jean-Michel Vernier, Robert Shoemaker. Discovery of potent CNS-penetrant covalent KRAS G12C inhibitors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2675.

959 OPTIMISING MEDICAL CARE IN OLDER EMERGENCY UROLOGY PATIENTS USING A GERIATRICIAN-LED PERI-OPERATIVE SERVICE

Introduction

Older and frail patients account for a large proportion of urology service use (Drch GW, Griebling TL., JAGS, 2003; 51: S355–8). Frail patients are at higher risk of complications and readmissions (Suskind A et al., BJUI, 2016; 117:836–42). Emergency patients may not be optimised before admission, leading to further increased risk and time restraints on care planning. Therefore, a geriatrician-led Perioperative Care for Older People Undergoing Surgery (POPS) service was established within the urology department at a District General Hospital to improve older emergency urology inpatients’ outcomes. We reviewed the impact on medical management, readmissions, and care planning.

Method

Retrospective documentation review of emergency urology patients aged over 65 admitted in the 3 months before the POPS service implementation, compared to those reviewed by POPS in the 3 months following. Median clinical frailty score of the POPS group was 6. The Comprehensive Geriatric Assessment based inpatient perioperative service was created using co-design and staff questionnaires were completed post-implementation.

Results

100% of staff (n = 26) would recommend POPS to other surgical wards and comments on improvements focused on expansion (9/15).

Conclusion

The POPS service significantly improved the recognition and management of medical conditions and reduced medical readmissions. Increased end of life recognition and planning allowed patients’ wishes to be acted on. This service was successfully implemented with high staff acceptance.

Evaluation of the Effects of Synovial Multipotent Cells on Deep Digital Flexor Tendon Repair in a Large Animal Model of Intra-Synovial Tendinopathy

Intra-synovial tendon injuries are a common orthopedic problem with limited treatment options. The synovium is a specialized connective tissue forming the inner encapsulating lining of diarthrodial joints and intra-synovial tendons. It contains multipotent mesenchymal stromal cells that render it a viable source of progenitors for tendon repair. This study evaluated the effects of autologous implantation of cells derived from normal synovium (synovial membrane cells [SMCs]) in augmenting repair in an ovine model of intra-synovial tendon injury. For this purpose, synovial biopsies were taken from the right digital flexor tendon sheath following creation of a defect to the lateral deep digital flexor tendon. Mononuclear cells were isolated by partial enzymatic digestion and assessed for MSC characteristics. Cell tracking and tendon repair were assessed by implanting 5 × 10⁶ cells into the digital flexor tendon sheath under ultrasound guidance with the effects evaluated using magnetic resonance imaging and histopathology. Synovial biopsies yielded an average 4.0 × 10⁵  ± 2.7 × 10⁵ SMCs that exhibited a fibroblastic morphology, variable osteogenic, and adipogenic responses but were ubiquitously strongly chondrogenic. SMCs displayed high expression of CD29 with CD271^NEGATIVE and MHC-II^LOW cell-surface marker profiles, and variable expression of CD73, CD90, CD105, CD166, and MHC-I. Implanted SMCs demonstrated engraftment within the synovium, though a lack of repair of the tendon lesion over 24 weeks was observed. We conclude healthy synovium is a viable source of multipotent cells, but that the heterogeneity of synovium underlies the variability between different SMC populations, which while capable of engraftment and persistence within the synovium exhibit limited capacity of influencing tendon repair. © 2019 The Authors. Journal of Orthopaedic Research^® published by Wiley Periodicals, Inc. on behalf of Orthopaedic Research Society J Orthop Res 38:128-138, 2020.

Congenital block vertebrae and intervertebral disc protrusion in a young cat

Case summary

A 6-month-old domestic shorthair cat was evaluated for proprioceptive ataxia of the pelvic limbs. Over 2 months, the cat became poorly ambulatory, paraparetic with proprioceptive ataxia and developed a firm, distended bladder with intermittent overflow urinary incontinence. Block vertebrae (T1-3, T4-5 and T10-11) and lordosis were identified on radiographs of the vertebral column. MRI revealed T3/4 intervertebral disc protrusion with severe extradural compression, secondary syringohydromyelia caudal to the protrusion and generalised intervertebral disc disease throughout the cervical and thoracic vertebrae. Dorsal laminectomy at T3/4 resulted in resolution of paraparesis and marked improvement in coordination and strength. Block vertebrae are usually considered an incidental finding. In this patient, angular deformation (lordosis) and adjacent segment disease probably contributed to clinically significant intervertebral disc degeneration and protrusion.

Relevance and novel information

There are few case reports in the literature of multiple congenital vertebral malformations causing neurological deficits in cats. This is the first reported case of successful surgical management of intervertebral disc protrusion, possibly secondary to block vertebrae and lordosis in a cat.

Virtual reality for management of pain in hospitalized patients: A randomized comparative effectiveness trial

Objectives

Therapeutic virtual reality (VR) has emerged as an effective, drug-free tool for pain management, but there is a lack of randomized, controlled data evaluating its effectiveness in hospitalized patients. We sought to measure the impact of on-demand VR versus “health and wellness” television programming for pain in hospitalized patients.

Methods

We performed a prospective, randomized, comparative effectiveness trial in hospitalized patients with an average pain score of ≥3 out of 10 points. Patients in the experimental group received a library of 21 VR experiences administered using the Samsung Gear Oculus headset; control patients viewed specialized television programming to promote health and wellness. Clinical staff followed usual care; study interventions were not protocolized. The primary outcome was patient-reported pain using a numeric rating scale, as recorded by nursing staff during usual care. Pre- and post-intervention pain scores were compared immediately after initial treatment and after 48- and 72-hours.

Results

There were 120 subjects (61 VR; 59 control). The mean within-subject difference in immediate pre- and post-intervention pain scores was larger in the VR group (-1.72 points; SD 3.56) than in the control group (-0.46 points; SD 3.01); this difference was significant in favor of VR (P < .04). When limited to the subgroup of patients with severe baseline pain (≥7 points), the effect of VR was more pronounced vs. control (-3.04, SD 3.75 vs. -0.93, SD 2.16 points; P = .02). In regression analyses adjusting for pre-intervention pain, time, age, gender, and type of pain, VR yielded a .59 (P = .03) and .56 (P = .04) point incremental reduction in pain versus control during the 48- and 72-hour post-intervention periods, respectively.

Conclusions

VR significantly reduces pain versus an active control condition in hospitalized patients. VR is most effective for severe pain. Future trials should evaluate standardized order sets that interpose VR as an early non-drug option for analgesia.

Abdominal Wall Schwannoma

This rare form of subcutaneous nodule can be identified through the combination of imaging and biopsy, but the definitive diagnosis is made on complete excision of the mass.

Finding Your Way When You Have Metastatic Breast Cancer: Codesigning Resources With Consumers for Consumers. The Signpost Study

Background: In Australia, women with metastatic breast cancer are not systematically made aware of or helped to access supportive care resources. Finding resources tailored to their needs can be challenging as they spread across several healthcare and advocacy organizations. Furthermore, resources assume varying levels of knowledge about the disease and its treatments, are fragmented and are dispersed across multiple organizations. Aim: The aim of our study was to codesign a signpost resource to direct women to key supportive care organizations that provide relevant, timely and comprehensive support for them; ensure women are made aware of and know how to access support they need, as and when they need it; and ensure that health professionals are aware of the resource, support its use, and distribute it to women. Methods: Using a codesign framework, initial development of the resource was guided by consumer representation on the study Steering Group. The resource was then presented to women living with metastatic breast cancer, and their advice obtained about its relevance and functionality during semistructured interviews. Purposive sampling based on age, time since diagnosis and geographical location (metro/regional), was used to obtain a variety of perspectives. Open-ended questions explored what the resource should contain, look like, and how it could best be introduced and distributed. An iterative descriptive analytical approach was applied. Results: Seven women aged 40-61 years were interviewed. Time since their metastatic breast cancer diagnosis ranged from 5 months to 19 years. Women told us about their preferences for style, content and format for the resource. They also guided discussion about how best to promote the resources in a way that both informed health professionals but also empowered women to find and express a need for support. As a result, 2 videos were produced. In the first 3-minute video for health professionals, consumers powerfully convey messages about the impact of their diagnosis, their need for support and how important it is for health professionals to “value and believe there are emotional, social and material aspects of coping with the disease” (this video will be shared in the presentation). In the second 4-minute video, consumers endorse the need for information and support, and women and consumers watching the video are introduced to the services provided by supportive care organizations profiled on the resource. Conclusion: Resources created and tailored by consumers for consumers are powerful and important. Consumer-led interventions that demonstrate to health professionals the importance of supportive care as a cornerstone of excellent cancer care may have a considerable impact but require empirical testing.

Surgical management of a cat with hepatic arterioportal fistula

A 9-month-old domestic short-haired cat presented with stunted growth and chronic gastrointestinal signs. Tachypnoea, a heart murmur and cranial abdominal bruit were detected on physical examination. Echocardiography revealed volume overload in all heart chambers. CT angiography identified an abnormal communication between the hepatic arterial circulation and the portal vein, along with multiple acquired shunts. The abnormal vascular communication was surgically ligated. Echocardiography documented improvement in cardiac parameters following surgery and the cat continues to have no clinical signs 39 months after surgery. This report describes successful surgical management of feline hepatic arterioportal fistula for the first time.

Clinical signs, imaging findings, and outcome in twelve cats with internal ophthalmoparesis/ophthalmoplegia

OBJECTIVE

To retrospectively evaluate the clinical signs, imaging findings, and outcome of feline internal ophthalmoparesis/ophthalmoplegia.

PROCEDURE

Medical records were reviewed from 2008 to 2015. Inclusion criteria included cats that presented with internal ophthalmoparesis/ophthalmoplegia, underwent diagnostic imaging, and had follow-up information available.

RESULTS

Twelve cases of feline internal ophthalmoparesis/ophthalmoplegia were identified. Nine cats were unilaterally affected, and three cats were bilaterally affected. Affected cats had a median age of 10.54 years (range 5.75 to 13.17), and both sexes of varying breeds were affected (nine males; three females). Clinical signs including abnormal mental status (n = 9; 75%) and additional neurologic abnormalities (n = 10; 83%) were observed. Magnetic resonance imaging and/or computed tomography (MRI/CT) of the head were performed in ten cats, revealing a mass lesion in all cases with varying locations. Multicentric lymphoma was diagnosed in two cats via abdominal ultrasound and cytology. All twelve cats were euthanized due to deterioration of clinical signs and/or quality-of-life concerns. Median time from diagnosis to euthanasia was 3.5 days (range 0 to 80 days).

CONCLUSIONS

Feline internal ophthalmoparesis/ophthalmoplegia rarely presents as the sole clinical sign in a referral hospital. Advanced imaging (MRI/CT) may be necessary to reach a definitive diagnosis in these cases. However, abdominal ultrasound would be advocated in cats with systemic clinical signs as a less expensive and less invasive diagnostic test to further investigate the possible etiology of internal ophthalmoparesis/ophthalmoplegia prior to advanced imaging. Feline cases with internal ophthalmoparesis/ophthalmoplegia associated with other intracranial signs and/or systemic clinical signs have a poor prognosis.

Rapid postoperative recurrence of a cranial multilobular tumor of bone in a young dog

Although resection of multilobular tumors of bone can be associated with a good prognosis and long disease‐free intervals in dogs, osteosarcomatous transformation should be considered a cause for rapid recurrence of clinical signs.

Surgical treatment of a paraspinal abscess with osteomyelitis and spinal cord compression in a rabbit

CASE DESCRIPTION A 16-month-old neutered male Continental Giant rabbit (Lepus curpaeums) was referred for evaluation of a 7-day history of acute-onset, progressive, symmetric paraparesis. CLINICAL FINDINGS On initial examination, the rabbit was nonambulatory, and results of neurologic examination were consistent with a lesion affecting the T3-L3 spinal cord segments. Thoracic radiography showed irregular widening of the left T11-12 articular process joint. Marked dorsolateral and lateral extradural spinal cord compression with contrast enhancement of the adjacent epaxial muscles was evident on MRI images of the spine. TREATMENT AND OUTCOME A left-sided T11-T12 hemilaminectomy was performed, which revealed an abnormal and hypertrophic T11-12 articular process joint and an osteolytic lesion communicating with the vertebral canal. Copious purulent material causing marked spinal cord compression was evident, and the surgical site was lavaged extensively with sterile (0.9% NaCl) saline solution. Results of aerobic, anaerobic, and enriched bacteriologic cultures of swab specimens obtained from the surgical site were negative. Histologic analysis of biopsy samples revealed chronic purulent osteomyelitis, myositis, and fasciitis with necrosis, fibrosis, and dystrophic mineralization. The rabbit was discharged 48 hours after surgery. Ten weeks after surgery, the rabbit was ambulatory with mild paraparesis. On telephone follow-up 21 months after surgery, the owners indicated that the rabbit was healthy and expressed satisfaction with the treatment and outcome. CLINICAL RELEVANCE Paraspinal abscess with vertebral canal involvement should be considered as a differential diagnosis for rabbits with clinical signs of progressive T3-L3 myelopathy. Outcome for the patient of the present report suggested that surgical treatment including decompression and debridement can result in a favorable long-term outcome.

Phase I clinical trial of sipuleucel-T combined with escalating doses of ipilimumab in progressive metastatic castrate-resistant prostate cancer

Background

Sipuleucel-T (SIP-T), which functions by stimulating cancer-specific dendritic cells, prolongs survival in men with prostate cancer. Ipilimumab (IPI) achieved a borderline survival advantage in a large randomized trial. SIP-T and IPI are potentially synergistic.

Patients and Methods

Nine men with progressive metastatic castrate-resistant prostate cancer (mCRPC) were treated prospectively with SIP-T followed immediately by IPI with one of the following doses of IPI: 1 mg/kg at 1 week after SIP-T; 1 mg/kg at 1 and 4 weeks after SIP-T; or 1 mg/kg at 1, 4, and 7 weeks after SIP-T. Three patients were evaluated at each level. Cancer-specific immunoglobulins directed at granulocyte-macrophage-colony-stimulating factor/prostatic acid phosphatase (PAP) fusion protein (PA2024) and PAP were measured prior to SIP-T, after SIP-T, 1 week after IPI, every other month for 5 months, then every 3 months for an additional 12 months.

Results

Adverse events of SIP-T were consistent with previous reports. IPI only caused a transient grade 1 rash in one patient. Median age, Gleason score, and number of previous hormonal interventions were 77 years, 8, and 3, respectively. Eight men had bone metastases and one had lymph node metastasis. Statistically significant increases in serum immunoglobulin G (IgG) and IgG-IgM specific for PA2024 and PAP occurred after SIP-T. An additional statistically significant increase in the aforementioned immunoglobulins – above the levels achieved by SIP-T – occurred after IPI. Median clinical follow-up was 36 months (range: 26–40). Three patients died from progressive disease after 9, 18, and 20 months. Out of the remaining six patients, five of them needed further treatment that included abiraterone acetate, enzalutamide, radium-223 dichloride, and spot radiation. One patient had an undetectable PSA, who did not receive any other treatment except spot radiation. Median PSA at last follow-up for the surviving patients was 3.8 (range: 0.6–7.47).

Conclusion

In this small trial, the addition of IPI to SIP-T was well tolerated. IPI increased immunoglobulins specific for the PA2024 protein and PAP above the level achieved with SIP-T alone.

TRUNCATION ARTIFACT IN MAGNETIC RESONANCE IMAGES OF THE CANINE SPINAL CORD

The truncation artifact in magnetic resonance (MR) images is a line of abnormal signal intensity that occurs parallel to an interface between tissues of markedly different signal intensity. In order to demonstrate the truncation artifact in sagittal images of the canine spinal cord and the effect of changing spatial resolution, we conducted an experimental in vitro study. A section of fixed canine spinal cord was imaged using a 1.5T magnet. Spatial resolution was increased by increasing the acquisition matrix and reconstruction matrix, producing series of T2-weighted (T2w) images with the following pixel sizes: A, 1.6 (vertical) × 2.2 mm² (horizontal); B, 1.2 × 1.7 mm² ; C, 0.8 × 1.1 mm² ; D, 0.4 × 0. 6 mm² . Plots of mean pixel value across the cord showed variations in signal intensity compatible with truncation artifact, which appeared as a single, wide central hyperintense zone in low-resolution images and as multiple narrower zones in high spatial resolution images. Even in images obtained using the highest spatial resolution available for the MR system, the edge of the spinal cord was not accurately defined and the central canal was not visible. The experiment was repeated using an unfixed spinal cord specimen with focal compression applied to mimic a pathologic lesion. Slight hyperintensity was observed within the spinal cord at the site of compression although the cord was normal histologically. Results of this study suggest that caution should be applied when interpreting hyperintensity affecting the spinal cord in T2w sagittal images of clinical patients because of the possibility that the abnormal signal could represent a truncation artifact.

Use of dual-phase contrast computed tomography for evaluation of the normal canine male genital tract

OBJECTIVES

To evaluate the use of dual-phase contrast-enhanced computed tomography for the depiction of the features of the male genital tract, highlighting differences between entire and neutered dogs.

METHODS

Computed tomography exams of 23 entire and 23 neutered male dogs with no history of urogenital disease were included in this retrospective study, with exams acquired pre-, 30 and 98·9 ±27·4 seconds after intravenous contrast administration. The genital structures were subjectively evaluated for visibility, contrast enhancement and enhancement pattern and differences between entire and neutered dogs were described. Objective measurements of attenuation and size of the prostatic tissue were acquired.

RESULTS

The root, body and glans of the penis could be evaluated in all dogs and appeared larger in entire dogs, though objective measurements could not be reliably made because these structures are small and curved. There was contrast enhancement of the cavernous structures, most reliably in the bulb and corpus spongiosum and most frequently in entire dogs in the delayed post-contrast phase. In entire dogs, the small testicular vessels most commonly had a vermiform shape in the early post-contrast phase, and a homogeneous appearance in the delayed phase. Sternal recumbency with the coxofemoral joints extended improved visibility of the genital structures.

CLINICAL SIGNIFICANCE

Dual-phase contrast-enhanced computed tomography is useful for depiction of the structures of the male genital tract, with the early phase especially highlighting the vascular and the delayed phase the cavernous structures.

Calculation of posterior chamber intraocular lens (IOL) size and dioptric power for use in pet rabbits undergoing phacoemulsification

OBJECTIVES

To calculate the size and dioptric power of a posterior chamber intraocular lens (IOL) to achieve emmetropia in adult rabbits and to compare the dioptric power calculation results using a proprietary predictive formula to a retinoscopy-based method.

ANIMALS STUDIED

Three wild rabbit cadavers, seven pet rabbits with cataracts and ten healthy pet rabbits.

MATERIALS AND METHODS

Implant size was calculated using a capsular tension ring (CTR) (Acrivet^® , Berlin, Germany). Published and cadaveric biometric data were used in the predictive formula. An IOL power-escalation study compared the predicted values to the refraction results of one pet rabbit (P1) fitted with a + 41D canine IOL (Acrivet^® ) and six pet rabbits (P2-P7) fitted with prototype IOLs (Acrivet^® ). Retinoscopy of 10 healthy pet rabbits served as controls.

RESULTS

A 13.5 mm CTR fitted in all rabbits and permitted the use of a 13 mm IOL. The predicted IOL power ranged between +24D and +25D. The +41D IOL resulted in a refraction error of +8D. Progressive recalculation through a calibration formula led to the insertion of three +49D IOLs in two pet rabbits and a refraction of +6D to +8D, followed by seven +58D IOLs in four pet rabbits and a refraction median of 0D (range: -1.5D to +1D).

CONCLUSIONS

A 13 mm prototype IOL of +58D achieves emmetropia and is of adequate size for rabbits. The combined use of a CTR and retinoscopy is a useful method to calculate the size and refractive power of a new, species-specific, veterinary IOL.

A novel protein isoform of the RON tyrosine kinase receptor transforms human pancreatic duct epithelial cells

The MST1R gene is overexpressed in pancreatic cancer producing elevated levels of the RON tyrosine kinase receptor protein. While mutations in MST1R are rare, alternative splice variants have been previously reported in epithelial cancers. We report the discovery of a novel RON isoform discovered in human pancreatic cancer. Partial splicing of exons 5 and 6 (P5P6) produces a RON isoform that lacks the first extracellular immunoglobulin-plexin-transcription domain. The splice variant is detected in 73% of xenografts derived from pancreatic adenocarcinoma patients and 71% of pancreatic cancer cell lines. Peptides specific to RON P5P6 detected in human pancreatic cancer specimens by mass spectrometry confirm translation of the protein isoform. The P5P6 isoform is found to be constitutively phosphorylated, present in the cytoplasm, and it traffics to the plasma membrane. Expression of P5P6 in immortalized human pancreatic duct epithelial (HPDE) cells activates downstream AKT, and in human pancreatic epithelial nestin-expressing cells, activates both the AKT and MAPK pathways. Inhibiting RON P5P6 in HPDE cells using a small molecule inhibitor BMS-777607 blocked constitutive activation and decreased AKT signaling. P5P6 transforms NIH3T3 cells and induces tumorigenicity in HPDE cells. Resultant HPDE-P5P6 tumors develop a dense stromal compartment similar to that seen in pancreatic cancer. In summary, we have identified a novel and constitutively active isoform of the RON tyrosine kinase receptor that has transforming activity and is expressed in human pancreatic cancer. These findings provide additional insight into the biology of the RON receptor in pancreatic cancer and are clinically relevant to the study of RON as a potential therapeutic target.

Assessment of G6PD screening program in premature infants in a NICU

OBJECTIVE

Targeted screening for glucose-6-phosphate dehydrogenase deficiency (G6PDdef) using fluorescent spot test (FST) is done in our newborn nursery (NN) and now in our NICU. Premature infants have higher G6PD levels than term infants. FST may result in under diagnosis of G6PDdef in preterms. We sought to determine if FST is appropriate for diagnosis of G6PDdef at<35 weeks and assess screening in NICU.

STUDY DESIGN

Retrospective chart review of male, inborn infants<35 weeks in NICU from 2008 to 2011. Difference in G6PDdef incidence<5% between NN and NICU was acceptable for equivalence.

RESULTS

Out of 679 subjects, 442 were screened for G6PDdef and 11.3% had abnormal results. Binomial testing comparing 11.3% (95% confidence interval (CI) 8.5 to 14.6) incidence of G6PDdef in NICU and reported incidence in NN (11%) demonstrated no difference. 12.2% of Black/African American males were not screened.

CONCLUSION

FST is appropriate for screening all at-risk newborns. A number of at-risk premature males were not screened.

Thoracic and lumbar vertebral bone mineral density changes in a natural occurring dog model of diffuse idiopathic skeletal hyperostosis

Ankylosing spinal disorders can be associated with alterations in vertebral bone mineral density (BMD). There is however controversy about vertebral BMD in patients wuse idiopathic skeletal hyperostosis (DISH). DISH in Boxer dogs has been considered a natural occurring disease model for DISH in people. The purpose of this study was to compare vertebral BMD between Boxers with and without DISH. Fifty-nine Boxers with (n=30) or without (n=29) DISH that underwent computed tomography were included. Vertebral BMD was calculated for each thoracic and lumbar vertebra by using an earlier reported and validated protocol. For each vertebral body, a region of interest was drawn on the axial computed tomographic images at three separate locations: immediately inferior to the superior end plate, in the middle of the vertebral body, and superior to the inferior end plate. Values from the three axial slices were averaged to give a mean Hounsfield Unit value for each vertebral body. Univariate statistical analysis was performed to identify factors to be included in a multivariate model. The multivariate model including all dogs demonstrated that vertebral DISH status (Coefficient 24.63; 95% CI 16.07 to 33.19; p <0.001), lumbar vertebrae (Coefficient -17.25; 95% CI -23.42 to -11.09; p < 0.01), and to a lesser extent higher age (Coefficient -0.56; 95% CI -1.07 to -0.05; p = 0.03) were significant predictors for vertebral BMD. When the multivariate model was repeated using only dogs with DISH, vertebral DISH status (Coefficient 20.67; 95% CI, 10.98 to 30.37; p < 0.001) and lumbar anatomical region (Coefficient -38.24; 95% CI, -47.75 to -28.73; p < 0.001) were again predictors for vertebral BMD but age was not. The results of this study indicate that DISH can be associated with decreased vertebral BMD. Further studies are necessary to evaluate the clinical importance and pathophysiology of this finding.

Acoustic neuroma manifesting as toothache and numbness

Acoustic neuroma, also known as vestibular schwannoma, is a rare benign brainstem tumour involving the abnormal growth and proliferation of Schwann cells surrounding the vestibular division of the eighth cranial nerve. Although the most common symptoms are non-dentally related, there are instances where diagnosis of this potentially life-threatening condition is triggered by an emergency presentation to the dentist for the most trivial of reasons. A 56-year-old male presented to a dental clinic complaining of a toothache. Following history taking, examination and radiographs a carious lower right molar was extracted. The patient reported relief but later described post-extraction numbness on the opposite side (left) of his lower jaw that could not be explained by anatomical principles or previous dental history. Further investigations revealed an acoustic neuroma as the underlying cause. This case highlights that not all signs and symptoms that occur in the mouth are abnormalities within the mouth. In particular, this case underscores the importance of recognizing that the spontaneous onset of certain symptoms may be due to significant non-dental pathology. Any numbness over the distribution of the trigeminal nerve must be investigated. The importance of the basic sciences and referring will also be emphasized.

Appearance of the canine meninges in subtraction magnetic resonance images

The canine meninges are not visible as discrete structures in noncontrast magnetic resonance (MR) images, and are incompletely visualized in T1-weighted, postgadolinium images, reportedly appearing as short, thin curvilinear segments with minimal enhancement. Subtraction imaging facilitates detection of enhancement of tissues, hence may increase the conspicuity of meninges. The aim of the present study was to describe qualitatively the appearance of canine meninges in subtraction MR images obtained using a dynamic technique. Images were reviewed of 10 consecutive dogs that had dynamic pre- and postgadolinium T1W imaging of the brain that was interpreted as normal, and had normal cerebrospinal fluid. Image-anatomic correlation was facilitated by dissection and histologic examination of two canine cadavers. Meningeal enhancement was relatively inconspicuous in postgadolinium T1-weighted images, but was clearly visible in subtraction images of all dogs. Enhancement was visible as faint, small-rounded foci compatible with vessels seen end on within the sulci, a series of larger rounded foci compatible with vessels of variable caliber on the dorsal aspect of the cerebral cortex, and a continuous thin zone of moderate enhancement around the brain. Superimposition of color-encoded subtraction images on pregadolinium T1- and T2-weighted images facilitated localization of the origin of enhancement, which appeared to be predominantly dural, with relatively few leptomeningeal structures visible. Dynamic subtraction MR imaging should be considered for inclusion in clinical brain MR protocols because of the possibility that its use may increase sensitivity for lesions affecting the meninges.

Older adult consumers' attitudes and preferences on electronic patient-physician messaging

OBJECTIVE

To evaluate and compare the attitudes and preferences of younger and older adults regarding health information exchange with providers, and identify barriers and limitations to meaningful use.

STUDY DESIGN

Cross-sectional study.

METHODS

Qualitative and quantitative data gathered from online surveys of younger and older adult patients enrolled in a freestanding, Internetbased patient-physician messaging system that requires an individual account. This messaging system is only a secure messaging center, and does not allow for direct access to personal medical records.

RESULTS

Data were collected from 324 patients (or proxy users) who reported their age, with 55.2% of respondents under the age of 65 years (mean age 48.2 years) and 44.8% of respondents 65 years or older (mean age 74.9 years). Family and non-family caregivers (proxy users) (mean age 59.2 years) comprised 21.0% of respondents. Overall, 83.9% of all respondents preferred to communicate with the provider via e-mail, and 84.5% of users found the messaging system easy to use, with a majority utilizing the messaging system to communicate about health questions and/or medication requests. Finally, 83% of user respondents were satisfied with the messaging system. Results highlight several areas where improvement is needed to increase patient use and satisfaction including adequate patient education, user-friendly interface, and provider engagement. No significant differences between the younger and older adult populations were found.

CONCLUSION

Although a majority of enrolled older adult patients have positive attitudes about health information exchange, electronic communication platforms must address key issues in consumer education, physician commitment, and adoption of an accessible interface to ensure productive older adult consumer participation.

"Let's get physical": advantages of a physical model over 3D computer models and textbooks in learning imaging anatomy

Three-dimensional (3D) information plays an important part in medical and veterinary education. Appreciating complex 3D spatial relationships requires a strong foundational understanding of anatomy and mental 3D visualization skills. Novel learning resources have been introduced to anatomy training to achieve this. Objective evaluation of their comparative efficacies remains scarce in the literature. This study developed and evaluated the use of a physical model in demonstrating the complex spatial relationships of the equine foot. It was hypothesized that the newly developed physical model would be more effective for students to learn magnetic resonance imaging (MRI) anatomy of the foot than textbooks or computer-based 3D models. Third year veterinary medicine students were randomly assigned to one of three teaching aid groups (physical model; textbooks; 3D computer model). The comparative efficacies of the three teaching aids were assessed through students' abilities to identify anatomical structures on MR images. Overall mean MRI assessment scores were significantly higher in students utilizing the physical model (86.39%) compared with students using textbooks (62.61%) and the 3D computer model (63.68%) (P < 0.001), with no significant difference between the textbook and 3D computer model groups (P = 0.685). Student feedback was also more positive in the physical model group compared with both the textbook and 3D computer model groups. Our results suggest that physical models may hold a significant advantage over alternative learning resources in enhancing visuospatial and 3D understanding of complex anatomical architecture, and that 3D computer models have significant limitations with regards to 3D learning.