A retrospective study of chemotherapeutic effect without wide-margin surgery or radiation therapy in dogs with oral malignant melanoma.

Background: Effective treatment for canine oral malignant melanoma (e.g., curative-intent surgery) may not be feasible or radiation therapy may be unavailable. However, chemotherapy is usually an option, and more information is needed regarding its use without adequate local treatments. Objective: Our objective was to investigate the efficacy of chemotherapy in canine oral malignant melanoma without adequate local control, using carboplatin with dose reduction in small-breed dogs and metronomic chemotherapy. Animals and procedure: Client-owned dogs with histopathologically diagnosed oral malignant melanoma were retrospectively enrolled from 2016 to 2022. The chemotherapy protocol in each case was determined by the attending clinician. Results: Thirteen dogs were included. The median progression-free interval of all 13 dogs was 42 d (14 to 953 d). The median overall survival time of dogs with chemotherapy as their only systemic treatment was 181 d (50 to 960 d; n = 11). The median dosage of carboplatin was 250 mg/m2. Response to treatment and clinical stage were significant prognostic factors. Conclusion and clinical relevance: As chemotherapy provided a median survival of 6 mo, it could be considered when adequate local control is infeasible. Earlier clinical stages or achievement of at least stable disease during chemotherapy may indicate better survival in dogs.

Une étude rétrospective de l'effet chimiothérapeutique sur le mélanome malin buccal canin dépourvu de chirurgie et de radiothérapie á large marge : le stade clinique et la réponse au traitement prédisent les résultats du patient. Mise en contexte: Des traitements efficaces pour le mélanome malin oral canin, tels que la chirurgie á visée curative, ne sont parfois pas réalisables ou la radiothérapie n'est pas disponible dans certaines régions. La chimiothérapie reste une option de traitement et davantage d'informations devraient être fournies pour les cas qui n'ont pas eu accés á un traitement local adéquat. Objectif: Cette étude visait á étudier l'efficacité de la chimiothérapie dans le mélanome malin oral canin sans contrôle local adéquat, en utilisant le carboplatine avec réduction de dose chez les chiens de petite race et la chimiothérapie métronomique. Animaux et procédure: Treize chiens appartenant á des clients atteints d'un mélanome malin oral diagnostiqué par histopathologie ont été rétrospectivement inscrits de 2016 á 2022. Le protocole de chimiothérapie a été déterminé par le clinicien traitant. Résultats: L'intervalle médian sans progression des treize chiens était de 42 jours (14­953 jours). La durée médiane de survie globale des chiens ayant reçu une chimiothérapie comme seul traitement systémique était de 181 jours (50­960 jours; n = 11). La dose médiane de carboplatine était de 250 mg/m2. La réponse au traitement et le stade clinique étaient des facteurs pronostiques importants. Conclusion et pertinence clinique: La chimiothérapie pouvait encore être envisagée lorsqu'un contrôle local adéquat était impossible. Des stades cliniques plus précoces ou des patients atteignant au moins une maladie stable pendant la chimiothérapie peuvent indiquer une meilleure survie.(Traduit par les auteurs).

Limited Clinical Efficacy with Potential Adverse Events in a Pilot Study of Autologous Adoptive Cell Therapy in Canine Oral Malignant Melanoma.

Adoptive cell therapy (ACT) has been studied in several human and canine cancers with some promising clinical outcomes but not in canine oral malignant melanoma (OMM). Our manuscript aimed to explore one kind of ACT, the ex vivo-expanded autologous immune cell infusion in canine OMM, as this tumor remains a treatment dilemma. The study recruited dogs with histopathological diagnoses of oral malignant melanoma, generated their peripheral blood mononuclear cells, expanded them into predominantly non-B non-T cells via stimulations of IL-15, IL-2, and IL-21, and then re-infused the cells into tumor-bearing dogs. Ten dogs were enrolled; three dogs did not report any adverse events; three had a mildly altered appetite; one had a mildly increased liver index, while the other three developed suspected anaphylaxis at different levels. The median progression-free interval was 49 days. Dogs with progressive disease during treatment had a shorter survival. This pilot study indicates limited efficacy with potential adverse events of this ACT. Most recruited patients were in a later stage and had macroscopic disease, which might affect the treatment efficacy. Further exploration of this cell therapy in an adjuvant setting, with adequate protocol modification and standardization, could still be considered.

Fundus imaging features of congenital rubella retinopathy.

PURPOSE: To evaluate the clinical characteristics of congenital rubella retinopathy (CRR) with modern fundus imaging. METHODS: Single-center case series. Eleven patients (2005-2020) at the Emory Eye Center with known or presumed CRR. Trained image readers reviewed fundus imaging (color fundus photography, widefield pseudocolor imaging, near-infrared reflectance imaging, autofluorescence imaging, and spectral-domain optical coherence tomography) for pre-specified features suggestive of CRR. RESULTS: Eleven patients with confirmed (63.6%) or presumed (36.3%) CRR were identified. All were female with median (range) age of 53 (35-67) years. Six (54.5%) were born during the 1964-1965 United States rubella epidemic. All had congenital hearing loss. Two (18.2%) had a congenital heart defect. Eleven (50.0%) eyes had salt-and-pepper retinal pigmentary changes. Twenty-two eyes (100.0%) had irregularly distributed regions of speckled hypoautofluorescence. One eye (4.5%) had a presumed macular neovascularization. CONCLUSION: Modern fundus imaging demonstrates characteristic features of CRR, even when pigmentary changes are not readily apparent on examination. Widefield autofluorescence findings of irregularly distributed speckled hypoautofluorescence are particularly revealing. This series of newly diagnosed adults with CRR may represent the milder end of the phenotypic spectrum of this condition, highlighting imaging findings that may aid in diagnostically challenging cases of CRR.

Nucleocapsid protein binding DNA aptamers for detection of SARS-COV-2.

The severe acute respiratory syndrome coronavirus (SARS-CoV-2) has infected millions of individuals and continues to be a major health concern worldwide. While reverse transcription-polymerase chain reaction remains a reliable method for detecting infections, limitations of this technology, particularly cost and the requirement of a dedicated laboratory, prevent rapid viral monitoring. Antigen tests filled this need to some extent but with limitations including sensitivity and specificity, particularly against emerging variants of concern. Here, we developed aptamers against the SARS-CoV-2 Nucleocapsid protein to complement or replace antibodies in antigen detection assays. As detection reagents in ELISA-like assays, our DNA aptamers were able to detect as low as 150 pg/mL of the protein and under 150 k copies of inactivated SARS-CoV-2 Wuhan Alpha strain in viral transport medium with little cross-reactivity to other human coronaviruses (HCoVs). Further, our aptamers were reselected against the SARS-CoV-2 Omicron variant of concern, and we found two sequences that had a more than two-fold increase in signal compared to our original aptamers when used as detection reagents against protein from the Omicron strain. These findings illustrate the use of aptamers as promising alternative detection reagents that may translate for use in current tests and our findings validate the method for the reselection of aptamers against emerging viral strains.

Visual Morbidity and Outcomes of Scleritis Associated with Intraocular Inflammation Compared to Isolated Scleritis.

PURPOSE: To compare visual outcomes, ocular complications and therapies for patients with scleritis-associated intraocular inflammation (SAI) and patients with isolated scleritis (IS). RESULTS: A total of 52 patients (36 with SAI and 16 with IS) were reviewed. Mean age (standard deviation) at presentation was 48.4 years old (± 15.4) in the SAI group and 53 years old (± 17.1) in the IS group (p = .37). Visual acuity was worse at presentation and last visit for patients with SAI compared to IS (p = .04). Patients in the SAI group developed greater posterior segment complications than in the IS group (p = .002). CONCLUSIONS: Scleritis with intraocular inflammation was associated with a higher rate of visual morbidity compared to isolated scleritis. More aggressive management strategies may be needed for patients who present with scleritis associated with inflammation.

Aptamer-Based Target Detection Facilitated by a 3-Stage G-Quadruplex Isothermal Exponential Amplification Reaction.

Aptamers are target-recognition molecules that bind with high affinity and specificity. These characteristics can be leveraged to control other molecules with signal-generation capability. For the system described herein, target recognition through an aptameric domain, Stem II of a modified hammerhead ribozyme, activates the self-cleaving ribozyme by stabilizing the initially unstructured construct. The cis-cleaving RNA acts at the junction of Stem III and Stem I, creating two cleavage products. The longer cleavage product primes an isothermal exponential amplification reaction (EXPAR) of the two similar catalytically active G-quadruplexes. Those resulting amplification products catalyze peroxidase reduction, which is coupled to the reduction of a colorimetric substrate with an output that the naked eye can detect. The 3-part system described in the present study improves detection modalities such as enzyme-linked immunosorbent assays (ELISAs) by producing a visually detectable signal for indicating the presence of as low as 0.5 µM theophylline in as little as 15 min.

Determining the Thermodynamic and Kinetic Association of a DNA Aptamer and Tetracycline Using Isothermal Titration Calorimetry.

The determination of binding affinity and behavior between an aptamer and its target is the most crucial step in selecting and using an aptamer for application. Due to the drastic differences between the aptamer and small molecules, scientists need to put much effort into characterizing their binding properties. Isothermal Titration Calorimetry (ITC) is a powerful approach for this purpose. ITC goes beyond determining disassociation constants (Kd) and can provide the enthalpy changes and binding stoichiometry of the interaction between two molecules in the solution phase. This approach conducts continuous titration using label-free molecules and records released heat over time upon the binding events produced by each titration, so the process can sensitively measure the binding between macromolecules and their small targets. Herein, the article introduces a step-by-step procedure of the ITC measurement of a selected aptamer with a small target, tetracycline. This example proves the versatility of the technique and its potential for other applications.

Investigation of Toxoplasma infection in zoo animals using multispecies ELISA and GRA7 nested PCR.

BACKGROUND: Toxoplasma is an obligate intracellular protozoan that causes an important zoonotic disease with a worldwide distribution. Felids are the definitive hosts of this parasite, while virtually all warm-blooded animals, including birds, serve as intermediate hosts. Four ring-tailed lemurs (Lemur catta) in the Taipei Zoo died of acute Toxoplasma infection in June 2019. Since then, Toxoplasma has occasionally been identified in this Zoo during necropsy of dead animals and PCR of animal blood samples. Therefore, a general survey of Toxoplasma infection in animals in the Zoo seems to be needed. METHODS AND RESULTS: An indirect multispecies ELISA was used for the first time to screen for Toxoplasma infection in 326 serum samples collected from 75 species of animals. The infection rate of Toxoplasma was 27% (88/326). A commercial latex agglutination (LAT) assay was used to re-examine the samples with doubtful and uncertain ELISA results (151 samples from 42 species). The infection rate increased to 36.2% (118/326), and the indirect multispecies ELISA appeared to be applicable to 31 of 75 species animals included in this study. Nested PCR assays targeting the dense granule protein 7 (GRA7) gene and B1 gene were also used to detect Toxoplasma in DNA samples extracted from 10 liver or blood specimens from 8 animals. GRA7 gene fragments were amplified from 8 samples from 7 animals, while B1 gene fragments were amplified from only 4 samples from 4 animals. From the B1 nested PCR and the sequence data of GRA7 fragments amplified from infectious specimens, the animals in the Zoo were speculated to have been infected by at least three different Toxoplasma variants. CONCLUSIONS: According to the serological investigation, we speculated that over one-third (36.2%) of animals in Taipei Zoo presented the infection of Toxoplasma, and the indirect multispecies ELISA we used can be applied to detect Toxoplasma infection in 31 animal species included in this study. Sequence analysis revealed that at least three Toxoplasma variants were infecting the animals of Taipei Zoo.

Multimodal diagnostic imaging in primary vitreoretinal lymphoma.

BACKGROUND: Primary vitreoretinal lymphoma (PVRL) is an aggressive lymphoma that may present with protean features and represents a diagnostic challenge. Given that patients with PVRL are at high risk of CNS involvement with a high mortality and morbidity rate, prompt diagnosis is crucial to initiate treatment early in the disease course. A multimodality imaging approach including fundus photography, fundus autofluorescence (FAF), optical coherence tomography (OCT), fluorescein and indocyanine angiography, and electroretinography (ERG) can provide information to establish a diagnosis and provide objective measures for management. We review key findings seen via these imaging modalities in patients with PVRL. OBSERVATIONS: Fundus photography can highlight commonly seen patterns of PVRL including vitritis, subretinal disease, retinal pigment epithelial (RPE) abnormalities, optic nerve edema, retinal detachment, and less typical retinitis-like lesions. FAF can identify characteristic patterns of hyper- and hypoautofluorescent signal abnormalities in the macula. Spectral-domain OCT will demonstrate vitreous cells, RPE nodularity, and hyperreflectivity of the outer retina. The presence of a hyper-reflective band in the subretinal space and infiltrates between the RPE and Bruch's membrane can assist in distinguishing PVRL from choroidal lymphoma. Vertical hyperreflective columns (VHRLs) are another pertinent finding that may represent microinfiltrates of the tumor. OCT has proven to be a particularly useful modality in assessing the progress of treatment in PVRL. Fluorescein angiography can show RPE changes, which include granularity, late staining at the RPE level, and blockage. Indocyanine green angiography (ICGA) primarily shows hypocyanescence, which corresponds to PVRL lesions on fundus photography and may occur secondary to loss of RPE and choriocapillaris. CONCLUSION: While PVRL remains a challenging disease to diagnose and follow, the use of a multimodality imaging approach may assist in establishing a diagnosis. Because of the anatomic spaces PVRL may affect, fundus photography, OCT, FAF, angiography, and ERG can identify key characteristics of the disease, differentiate PVRL from other diseases, and provide baseline information for targeted systemic and local therapies. Further assessment of anatomic and functional targets will aid our clinical application of multimodal imaging in the management of PVRL.

Management of an atypical case of post-operative endophthalmitis presenting as angle-closure glaucoma.

BACKGROUND/PURPOSE: To report an atypical presentation of postoperative endophthalmitis after cataract surgery that initially presented as angle-closure glaucoma and to discuss challenges with the case management due to the unusual presentation and patient non-compliance. METHODS: Observational case report. B-scan ultrasound and ultrasound biomicroscopy. RESULTS: A 69-year-old Caucasian male with a 1-week history of uncomplicated cataract surgery was referred to our glaucoma clinic due to vision loss and concern for angle closure glaucoma. Anterior segment exam showed 360 degrees of flat anterior chamber (AC) with no hypopyon. A diagnosis of postoperative endophthalmitis was established when a B-scan ultrasound showed dense vitreous opacities. The patient underwent a pars plana vitrectomy (PPV), AC reformation, peripheral iridectomy, and intravitreal injection of antibiotics for treatment of endophthalmitis in the presence of an angle-closure glaucoma with good visual recovery. CONCLUSION: A low threshold for suspicion of endophthalmitis is needed after any routine intraocular procedure. An atypical presentation may masquerade as another pathology that delays the true diagnosis and treatment. Timely intervention in postoperative endophthalmitis is crucial in preserving vision.

Surgical Outcomes of Progressive Retinoschisis-Related Retinal Detachments: A 17-Year Survey From a Large Academic Center.

BACKGROUND AND OBJECTIVE: To provide an overview of progressive retinoschisis-related retinal detachment (RSRD) management at a tertiary referral center. MATERIALS AND METHODS: Single-institution retrospective case series from January 1, 2003, to May 1, 2020. RESULTS: Progressive RSRD occurred in 0.9% of patients with retinoschisis. Mean (range) age at time of surgery was 58.7 years (40.0 to 74.0). Ten eyes were initially treated with scleral buckle, three eyes with vitrectomy, and three eyes with combined scleral buckle and vitrectomy. Overall reattachment rate was 100.0%; single-surgery success was 56.2%. Proliferative vitreoretinopathy developed in 10.0% of scleral buckles, 33.3% of vitrectomies, and 33.3% of combined surgeries. CONCLUSIONS: Progressive RSRD is rare and poses surgical management challenges. Final retinal attachment can be achieved successfully but often requires secondary and staged surgeries. Localization of outer retinal breaks may help guide surgical management. Further research-such as a large-scale, prospective, multicenter, randomized trial-would be needed to determine the optimal surgical technique. [Ophthalmic Surg Lasers Imaging Retina. 2022;53:132-138.].

Evaluation of intravitreal topotecan dose levels, toxicity and efficacy for retinoblastoma vitreous seeds: a preclinical and clinical study.

BACKGROUND: Current melphalan-based intravitreal regimens for retinoblastoma (RB) vitreous seeds cause retinal toxicity. We assessed the efficacy and toxicity of topotecan monotherapy compared with melphalan in our rabbit model and patient cohort. METHODS: Rabbit experiments: empiric pharmacokinetics were determined following topotecan injection. For topotecan (15 µg or 30 µg), melphalan (12.5 µg) or saline, toxicity was evaluated by serial electroretinography (ERG) and histopathology, and efficacy against vitreous seed xenografts was measured by tumour cell reduction and apoptosis induction. PATIENTS: retrospective cohort study of 235 patients receiving 990 intravitreal injections of topotecan or melphalan. RESULTS: Intravitreal topotecan 30 µg (equals 60 µg in humans) achieved the IC90 across the rabbit vitreous. Three weekly topotecan injections (either 15 µg or 30 µg) caused no retinal toxicity in rabbits, whereas melphalan 12.5 µg (equals 25 µg in humans) reduced ERG amplitudes 42%-79%. Intravitreal topotecan 15 µg was equally effective to melphalan to treat WERI-Rb1 cell xenografts in rabbits (96% reduction for topotecan vs saline (p=0.004), 88% reduction for melphalan vs saline (p=0.004), topotecan vs melphalan, p=0.15). In our clinical study, patients received 881 monotherapy injections (48 topotecan, 833 melphalan). Patients receiving 20 µg or 30 µg topotecan demonstrated no significant ERG reductions; melphalan caused ERG reductions of 7.6 µV for every injection of 25 µg (p=0.03) or 30 µg (p<0.001). Most patients treated with intravitreal topotecan also received intravitreal melphalan at some point during their treatment course. Among those eyes treated exclusively with topotecan monotherapy, all eyes were salvaged. CONCLUSIONS: Taken together, these experiments suggest that intravitreal topotecan monotherapy for the treatment of RB vitreous seeds is non-toxic and effective.

Expanded Clinical Spectrum of Pentosan Polysulfate Maculopathy: A Macula Society Collaborative Study.

PURPOSE: Explore the spectrum of clinical manifestations of pentosan polysulfate sodium (PPS) maculopathy observed across a range of practice settings. DESIGN: Multi-institutional retrospective study. PARTICIPANTS: Patients exhibiting findings suggestive of PPS maculopathy identified from April 30, 2019, to December 4, 2020. METHODS: Members of the Macula Society submitted cases of presumed PPS maculopathy for consideration in this series. Diagnosis was confirmed by masked review of fundus imaging. Clinical characteristics of confirmed cases were summarized with descriptive statistics. MAIN OUTCOME MEASURES: Pentosan polysulfate exposure characteristics and fundus imaging features. RESULTS: There were 74 patients with PPS maculopathy included in the current study. Median (interquartile range) age at diagnosis was 62.0 years (56.0-65.8). The median duration of exposure to PPS was 14.0 years (10.2-18.9), with a median cumulative exposure of 1.5 kg (0.9-2.4). The most common presenting symptom was decreased or blurry vision (66.2%), followed by prolonged dark adaption or nyctalopia (32.4%). The most common referral diagnosis was age-related macular degeneration (54.1%); 16.2% of patients were referred for suspected PPS maculopathy. Novel imaging findings emerged, including highly asymmetric disease in 2 patients and a prominent vitelliform maculopathy in 2 patients. CONCLUSIONS: Most patients with PPS maculopathy exhibit characteristic findings on multimodal fundus imaging in the setting of high cumulative exposure to the oral drug. Some patients in the current study manifested novel imaging findings, expanding our understanding of the phenotypic spectrum of this condition. We recommend considering standardized ophthalmic screening of patients treated with PPS.

L-Asparaginase, Doxorubicin, Vincristine, and Prednisolone (LHOP) Chemotherapy as a First-Line Treatment for Dogs with Multicentric Lymphoma.

Cyclophosphamide exhibits the weakest therapeutic effect compared with vincristine and doxorubicin in the CHOP (C, cyclophosphamide; H, doxorubicin; O, vincristine; and P, prednisolone) chemotherapeutic protocol for the treatment of canine lymphoma. Twenty dogs with multicentric lymphoma were treated using the LHOP protocol, which used l-asparaginase in place of cyclophosphamide, and the outcomes were historically compared with those of dogs that received CHOP chemotherapy in the same institution. No significant differences were found in age (p = 0.107), body weight (p = 0.051), sex (p = 0.453), clinical stage V (p = 1), substage b (p = 0.573), T-cell phenotype (p = 0.340), overall response (p = 1), and hypercalcaemia status (p = 1) between the LHOP and CHOP groups. The adverse effects of l-asparaginase were well tolerated and self-limiting. The median PFS (progression-free survival) and median ST (survival time) in the LHOP group were 344 days (range: 28-940 days) and 344 days (range: 70-940 days), respectively. The median PFS and median ST in the CHOP group were 234 days (range: 49-1822 days) and 314 days (range: 50-1822 days), respectively. The dogs that received LHOP chemotherapy had a significantly longer PFS than the dogs that received CHOP chemotherapy (p = 0.001). No significant difference was observed in ST between the LHOP and CHOP groups (p = 0.131). Our study findings thus indicate that the LHOP protocol can be used as a first-line chemotherapeutic protocol in canine multicentric lymphoma.

Intravitreal melphalan hydrochloride vs propylene glycol-free melphalan for retinoblastoma vitreous seeds: Efficacy, toxicity and stability in rabbits models and patients.

The use of intravitreal chemotherapy has revolutionized the treatment of advanced intraocular retinoblastoma, as intravitreal melphalan has enabled difficult-to-treat vitreous tumor seeds to be controlled, leading to many more eyes being saved. However, melphalan hydrochloride (MH) degrades rapidly in solution, increasing logistical complexity with respect to time between medication preparation and administration for intravitreal administration under anesthesia for retinoblastoma. A new propylene glycol-free melphalan (PGFM) formulation has greater stability and could therefore improve access and adoption of intravitreal chemotherapy, allowing more children to retain their eye(s). We compared the efficacy and toxicity of both formulations, using our rabbit xenograft model and clinical patient experience. Three weekly 12.5 µg intravitreal injections of MH or PGFM (right eye), and saline (left eye), were administered to immunosuppressed rabbits harboring human WERI-Rb1 vitreous seed xenografts. Residual live cells were quantified directly, and viability determined by TUNEL staining. Vitreous seeds were reduced 91% by PGFM (p = 0.009), and 88% by MH (p = 0.004; PGFM vs. MH: p = 0.68). All residual cells were TUNEL-positive (non-viable). In separate experiments to assess toxicity, three weekly 12.5 µg injections of MH, PGFM, or saline were administered to non-tumor-bearing rabbits. Serial electroretinography, optical coherence tomography (OCT) and OCT-angiography were performed. PGFM and MH both caused equivalent reductions in electroretinography amplitudes, and loss of retinal microvasculature on OCT-angiography. The pattern of retinal degeneration observed on histopathology suggested that segmental retinal toxicity associated with all melphalan formulations was due to a vitreous concentration gradient-effect. Efficacy and toxicity were assessed for PGFM given immediately (within 1 h of reconstitution) vs. 4 h after reconstitution. Immediate- and delayed-administration of PGFM showed equivalent efficacy and toxicity. In addition, we evaluated efficacy and toxicity in patients (205 eyes) with retinoblastoma vitreous seeds, who were treated with a total of 833 intravitreal injections of either MH or PGFM as standard of care. Of these, we analyzed 118 MH and 131 PGFM monotherapy injections in whom serial ERG measurements were available to model retinal toxicity. Both MH and PGFM caused reductions in electroretinography amplitudes, but with no statistical difference between formulations. Comparing those patient eyes treated exclusively with PGFM versus those treated exclusively with MH, efficacy for tumor control and globe salvage was equivalent (PGFM vs. MH: 96.2% vs. 93.8%, p = 0.56), but PGFM-treated eyes received fewer injections than MH-treated eyes (average 3.2 ± 1.9 vs. 6.4 ± 2.1 injections, p < 0.0001). Taken together, these rabbit experiments and our clinical experience in retinoblastoma patients demonstrate that MH and PGFM have equivalent efficacy and toxicity. PGFM was more stable, with no decreased efficacy or increased toxicity even 4 h after reconstitution. We therefore now use PGFM over traditional MH for our patients for intravitreal treatment of retinoblastoma.

Association between weight change during initial chemotherapy and clinical outcome in dogs with multicentric lymphoma.

The majority of the known prognostic factors in dogs with lymphoma have been evaluated before treatment commences or at the time of diagnosis. Prognostic factors evaluated during the initial phase of treatment are less described but may provide important clinical information. In this retrospective study, 82 canine lymphoma patients were categorized according to the weight change between diagnosis and after 5 weeks of chemotherapy. Dogs that gained greater than 5% or lost greater than 5% of initial body weight were categorized as increased- or decreased-weight groups, respectively. Those in which weight changed less than 5% were categorized as the maintained-weight group. The median progression-free survival (PFS) in the increased-weight group, maintained-weight group and decreased-weight group was 226, 256 and 129 days, respectively. The decreased-weight group had significantly shorter PFS than the increased and maintained groups (P = .023, P = .003, respectively). The median survival time (ST) in the increased-weight group, maintained-weight group and decreased-weight group was 320, 339 and 222 days, respectively. There was no significant difference in ST among the three groups (P = .128). In Cox-regression results, weight change group and initial body weight were significant risk factors associated to PFS (P = .007, P = .001, respectively) while only patient's initial body weight was a significant risk factor to ST (P = .013). In conclusion, evaluation of initial body weight and weight changes over time can provide valuable information regarding PFS and ST in dogs with multicentric lymphoma.

Kynurenine 3-monooxygenase (KMO), and signal transducer and activator of transcription 3 (STAT3) expression is involved in tumour proliferation and predicts poor survival in canine melanoma.

Canine melanoma is a malignant tumour that exhibits aggressive behaviour, and frequently metastasizes to regional lymph nodes and distant sites. Currently, there are no effective treatments or practical prognostic biomarkers for canine melanoma. The enzyme kynurenine 3-monooxygenase (KMO), which plays a central role in the tryptophan metabolism, has previously been identified as the main pathogenic factor in neurodegenerative diseases; however, it has recently been found to be positively associated with tumour malignancy in human hepatocellular carcinoma and canine mammary tumours. Signal transducer and activator of transcription 3 (STAT3) is a well-known oncoprotein contributing to the proliferation, survival, invasiveness and metastasis of a variety of cancers. Although whether STAT3 and KMO collaborate in tumorigenesis needs to be further verified, our previous findings showed that inhibition of KMO activity reduced activation of STAT3. This study investigated the expressions of KMO and STAT3/phosphorylated (pSTAT3) by immunohistochemical analysis in 85 cases of canine melanoma, showing their expression levels were high within highly mitotic melanoma cells. KMO Overexpression was significantly associated with increased STAT3 and pSTAT3 expressions. Melanoma tissues with higher KMO, STAT3 and pSTAT3 protein expressions were correlated with reduced survival rates of the canine patients. Moreover, inhibition of KMO activity in canine melanoma cells resulted in reduced cell viability, in addition to decreased expressions of STAT3 and pSTAT3. Our results indicated the significance of KMO and the potential role of KMO/STAT3 interaction in enhancing tumour development. Additionally, KMO and STAT3/pSTAT3 may be viewed as useful biomarkers for the prediction of prognosis of canine melanoma.

TOXICITY AND EFFICACY OF INTRAVITREAL MELPHALAN FOR RETINOBLASTOMA: 25 µg Versus 30 µg.

PURPOSE: To compare retinal toxicity as measured by electroretinogram, ocular, and patient survival in retinoblastoma treated with intravitreal melphalan at two concentrations (25 vs. 30 µg). METHODS: Single-center, retrospective analysis of retinoblastoma eyes receiving 25-µg or 30-µg intravitreal melphalan from September 2012 to January 2019. Ocular toxicity was measured by electroretinogram of evaluable injections in 449 injections in 136 eyes. A repeated-measures linear mixed model with a random intercept and slope was applied to account for repeated measures for each eye. RESULTS: Average decline in electroretinogram after each additional injection was -4.9 µV (95% confidence interval -6.3 to -3.4); electroretinogram declined by -4.6 µV (95% confidence interval -7.0 to -2.2) after 25-µg injections and -5.2 µV (95% confidence interval -6.6 to -3.8) after 30-µg injections (P = 0.66). Injection at a new clock site hour was associated with a -3.91-µV lower average (95% confidence interval -7.8 to -0.04). CONCLUSION: Electroretinogram-measured toxicity in retinoblastoma eyes treated with intravitreal injections was not found to be different across 25-µg and 30-µg injections. There were no cases of extraocular extension or metastatic deaths in our patient population.

Genome-wide DNA methylation analysis using MethylCap-seq in canine high-grade B-cell lymphoma.

DNA methylation is a comprehensively studied epigenetic modification and plays crucial roles in cancer development. In the present study, MethylCap-seq was used to characterize the genome-wide DNA methylation patterns in canine high-grade B-cell lymphoma (cHGBL). Canine methylated DNA fragments were captured and the MEDIUM-HIGH and LOW fraction of methylated DNA was obtained based on variation in CpG methylation density. In the MEDIUM-HIGH and LOW fraction, 2144 and 1987 cHGBL-specific hypermethylated genes, respectively, were identified. Functional analysis highlighted pathways strongly related to oncogenesis. The relevant signaling pathways associated with neuronal system were also revealed, echoing recent novel findings that neurogenesis plays key roles in tumor establishment. In addition, 14 genes were hypermethylated in all the cHGBL cases but not in the healthy dogs. These genes might be potential signatures for tracing cHGBL, and some of them have been reported to play roles in various types of cancers. Further, the distinct methylation pattern of cHGBL showed a concordance with the clinical outcome, suggesting that aberrant epigenetic changes may influence tumor behavior. In summary, our study characterized genome-wide DNA methylation patterns using MethylCap-seq in cHGBL; the findings suggest that specific DNA hypermethylation holds promise for dissecting tumorigenesis and uncovering biomarkers for monitoring the progression of cHGBL.

Outcome of Canine Multicentric Lymphoma after Single or Divided Treatment with Cyclophosphamide in Multidrug Chemotherapy.

Cyclophosphamide is commonly used in combination chemotherapy to treat dogs with lymphoma. The metabolite of cyclophosphamide, acrolein, can irritate urinary bladder and cause sterile hemorrhagic cystitis. Dividing the administration of cyclophosphamide across multiple days may reduce the concentration of this metabolite in urinary bladder and reduce the possibility of cystitis. However, the impact of the therapeutic effect of this modification is not evaluated and compared to traditional single maximum-tolerated dose regimen. Seventy-two dogs with multicentric lymphoma received either bolus doses or divided doses of cyclophosphamide were included in this study. The incidence of hemorrhagic cystitis between 2 cyclophosphamide treatment groups was not significantly different (P = .357). There was no statistical difference in progression-free survival and survival time between 2 groups (P = .267 and P = .346). This modification of cyclophosphamide administration did not reduce the side effect of cystitis or affect remission and survival times in lymphoma dogs.