Development of a virtual reality simulator for training canine endotracheal intubation technique and evaluation of the educational impacts

Virtual reality (VR)-based training has shown some benefits in medical education, supporting skill acquisition, and helping reduce anxiety in real-world settings. However, the use of VR simulators in veterinary education remains limited. This study aimed to introduce a VR simulator to support veterinarian training in canine anaesthesia induction and endotracheal intubation. This study involved a group that learned solely with instructional videos (video group), and one that learned concurrently with the video and VR simulator (VR group). Third- and fourth-year veterinary students were included and underwent a descriptive test on canine endotracheal intubation. Canine endotracheal intubation success rates were compared between the video (n = 364) and VR (n = 60) groups of fifth-year students. A survey on the VR usability was conducted (n=91). The median descriptive test scores improved in the VR (63.3/100) vs the video group (51.5/100). The canine intubation success rates were comparable in the VR and video groups at 84.3% and 77.4%, respectively. A total of 90.1% of the surveyed students rated the ease of use of the simulator highly. Overall, VR simulators were well-received, suggesting benefits in new skill retention. Further studies are required to evaluate the extent of skill improvement through VR-based training, compared to conventional methods, and to assess its impact on student motivation. Evaluating the long-term effects of VR-based training on skill development and retention will also provide a deeper understanding of its educational benefits.

descSPIM: an affordable and easy-to-build light-sheet microscope optimized for tissue clearing techniques

Despite widespread adoption of tissue clearing techniques in recent years, poor access to suitable light-sheet fluorescence microscopes remains a major obstacle for biomedical end-users. Here, we present descSPIM (desktop-equipped SPIM for cleared specimens), a low-cost ($20,000-50,000), low-expertise (one-day installation by a non-expert), yet practical do-it-yourself light-sheet microscope as a solution for this bottleneck. Even the most fundamental configuration of descSPIM enables multi-color imaging of whole mouse brains and a cancer cell line-derived xenograft tumor mass for the visualization of neurocircuitry, assessment of drug distribution, and pathological examination by false-colored hematoxylin and eosin staining in a three-dimensional manner. Academically open-sourced ( https://github.com/dbsb-juntendo/descSPIM ), descSPIM allows routine three-dimensional imaging of cleared samples in minutes. Thus, the dissemination of descSPIM will accelerate biomedical discoveries driven by tissue clearing technologies.

Impact of the State of Emergency Declaration for Severe Acute Respiratory Syndrome Coronavirus-2 Pandemic Suppression on Individuals with Type 1 Diabetes Mellitus

Objective To examine the impact of lifestyle changes caused by the first emergency declaration issued in 2020 on glycemic control and body weight changes in Japanese individuals with type 1 diabetes mellitus. Methods This study included Japanese individuals with type 1 diabetes mellitus who visited Tokyo Women's Medical University Hospital between January 2019 and September 2020 (n=278). Seasonal changes in glycated hemoglobin (HbA1c) levels and the body mass index (BMI) were compared. A self-administered questionnaire regarding changes in treatment, diet, exercise, sleep, and telecommuting was used to assess lifestyle changes. Results Although HbA1c levels decreased from winter to summer in 2019 and 2020, the annual change was slightly but significantly greater in 2020 than in 2019. Seasonal changes in the BMI between 2019 and 2020 were also significantly different. An increase in the daily insulin dose, overall blood glucose level, diurnal change in blood glucose level, and food intake were significantly associated with increased HbA1c levels. Furthermore, HbA1c levels decreased with increasing moderate physical activity and sleep duration. The change in the BMI increased with increasing insulin dose, overall high blood glucose levels, and food intake. However, an increase in moderate physical activity was associated with a decrease in the BMI. HbA1c levels were significantly lower after the first emergency declaration in individuals with type 1 diabetes mellitus than that before the emergency declaration, even after accounting for seasonal variations. Conclusion Decreased HbA1c levels were associated with a decreased food intake, increased moderate exercise, and increased sleep duration during the state of emergency. The BMI remained relatively unchanged.

Alleviation of Dyspnea and Changes in Physical Activity Level by Air Flow to the Face With a Fan

BACKGROUND

Dyspnea is an unpleasant subjective symptom and is associated with decreased physical activity level (PAL). Effect of blowing air toward the face has received a great deal of attention as a symptomatic therapy for dyspnea. However, little is known about the duration of its effect and its impact on PAL. Therefore, this study aimed to measure dyspnea severity and changes in dyspnea and PALs with air blasts to the face.

METHODS

The trial conducted was open-label, randomized, and controlled. This study included out-patients with dyspnea caused by chronic respiratory deficiency. Subjects were provided a small fan and instructed to blow air toward their faces either twice a day or when having trouble breathing. Subsequently, severity of dyspnea and PALs was measured using visual analog scale and physical activity scale for the elderly (PASE), respectively, before and after 3-week treatment. Amounts of changes in dyspnea and PALs before and after treatment were compared using analysis of covariance.

RESULTS

Overall, 36 subjects were randomized, and 34 were analyzed. Mean age was 75.4 y (26 males [76.5%] and 8 females [23.5%]). Visual analog scale score for dyspnea (SD) before treatment was 33 (13.9) mm and 42 (17.5) mm in the control and intervention groups, respectively. PASE score before treatment was 78.0 (45.1) and 57.7 (38.0) in the control and intervention groups, respectively. No significant difference in changes in dyspnea severity and PAL was observed between the 2 groups.

CONCLUSIONS

No significant difference was observed for dyspnea and PALs in subjects after blowing air toward their own faces with a small fan for 3 weeks at home. Disease variability and impact of protocol violations were high due to small number of cases. Further studies with a design focused on subject protocol adherence and measurement methods are required to understand impact of air flow on dyspnea and PAL.

Safety and clinical efficacy of an anti-PD-L1 antibody (c4G12) in dogs with advanced malignant tumours

Immune checkpoint inhibitors (ICIs) have been developed for canine tumour treatment, and pilot clinical studies have demonstrated their antitumour efficacy in dogs with oral malignant melanoma (OMM). Although ICIs have been approved for various human malignancies, their clinical benefits in other tumour types remain to be elucidated in dogs. Here, we conducted a clinical study of c4G12, a canine chimeric anti-PD-L1 antibody, to assess its safety and efficacy in dogs with various advanced malignant tumours (n = 12) at the Veterinary Teaching Hospital of Hokkaido University from 2018 to 2023. Dogs with digit or foot pad malignant melanoma (n = 4), osteosarcoma (n = 2), hemangiosarcoma (n = 1), transitional cell carcinoma (n = 1), nasal adenocarcinoma (n = 1), B-cell lymphoma (n = 1), or undifferentiated sarcoma (n = 2) were treated with 2 or 5 mg/kg c4G12 every 2 weeks. Treatment-related adverse events of any grade were observed in eight dogs (66.7%), including elevated aspartate aminotransferase (grade 3) in one dog (8.3%) and thrombocytopenia (grade 4) in another dog (8.3%). Among dogs with target disease at baseline (n = 8), as defined by the response evaluation criteria for solid tumours in dogs (cRECIST), one dog with nasal adenocarcinoma and another with osteosarcoma experienced a partial response (PR), with an objective response rate of 25.0% (2 PR out of 8 dogs; 95% confidence interval: 3.2-65.1%). These results suggest that c4G12 is safe and tolerable and shows antitumor effects in dogs with malignant tumours other than OMM. Further clinical studies are warranted to identify the tumour types that are most likely to benefit from c4G12 treatment.

Recovery of hypoglycemic confidence using intermittently scanned continuous glucose monitoring among adults with type 1 diabetes with level 3 hypoglycemia: A prospective, single-center, single-arm study

AIM

To investigate whether the FreeStyle Libre, an intermittent scanning continuous glucose monitoring (isCGM) system, influences confidence in managing hypoglycemia in adults with type 1 diabetes.

MATERIALS AND METHODS

This longitudinal, observational study conducted at one facility included 121 adults with type 1 diabetes. Participants used the conventional finger-prick method for self-testing glucose before using isCGM. At baseline and 12 months after initiating isCGM, the Hypoglycemic Confidence Scale (HCS), Diabetes Treatment Satisfaction Questionnaire (DTSQ), and HbA1c were performed. At 12 months, the percentage of individuals utilizing isCGM trend arrows for glucose management was observed. The primary endpoint was hypoglycemic confidence change attributed to using isCGM.

RESULTS

After using isCGM, HCS scores improved significantly from 2.89 (2.56, 3.22) to 3.00 (2.20, 3.33) (p < 0.001); median (25%, 75%). Among participants with level 3 hypoglycemia at baseline, hypoglycemic confidence during sleep (p < 0.05), in social situations (p < 0.05), and in avoiding serious hypoglycemia-related problems (p < 0.05) were improved. Despite hypoglycemia risk, participants could continue daily activities by using isCGM (p < 0.05), and sixty-nine percent utilized trend arrows effectively.

CONCLUSION

Using isCGM improved hypoglycemic confidence among adults with type 1 diabetes. Data analysis indicated that people with type 1 diabetes could live more freely and better manage hypoglycemia using isCGM.

Spatiotemporal commonality of the TCR repertoire in a T-cell memory murine model and in metastatic human colorectal cancer

Immune checkpoint inhibitors (ICIs) have shown superior clinical responses and significantly prolong overall survival (OS) for many types of cancer. However, some patients exhibit long-term OS, whereas others do not respond to ICI therapy at all. To develop more effective and long-lasting ICI therapy, understanding the host immune response to tumors and the development of biomarkers are imperative. In this study, we established an MC38 immunological memory mouse model by administering an anti-PD-L1 antibody and evaluating the detailed characteristics of the immune microenvironment including the T cell receptor (TCR) repertoire. In addition, we found that the memory mouse can be established by surgical resection of residual tumor following anti-PD-L1 antibody treatment with a success rate of > 40%. In this model, specific depletion of CD8 T cells revealed that they were responsible for the rejection of reinoculated MC38 cells. Analysis of the tumor microenvironment (TME) of memory mice using RNA-seq and flow cytometry revealed that memory mice had a quick and robust immune response to MC38 cells compared with naïve mice. A TCR repertoire analysis indicated that T cells with a specific TCR repertoire were expanded in the TME, systemically distributed, and preserved in the host for a long time period. We also identified shared TCR clonotypes between serially resected tumors in patients with colorectal cancer (CRC). Our results suggest that memory T cells are widely preserved in patients with CRC, and the MC38 memory model is potentially useful for the analysis of systemic memory T-cell behavior.

Negative Influence of Aging on Differentiation and Proliferation of CD8+ T-Cells in Dogs

Immunosenescence is an age-related change in the immune system characterized by a reduction in naïve T-cells and an impaired proliferative capacity of CD8+ T-cells in older individuals. Recent research revealed the crucial impact of immunosenescence on the development and control of cancer, and aging is one of the causes that diminish the therapeutic efficacy of cancer immunotherapies targeting CD8+ T-cell activation. Despite dog cancer being defined as an age-related disease, there are few fundamental understandings regarding the relationship between aging and the canine immune system. Therefore, we aimed to elucidate the characteristics of immunosenescence in dogs and analyzed the effects of aging on the differentiation status and proliferation of canine CD8+ T cells using T-cell specific stimulation with anti-canine CD3/CD28 antibody-coated beads and interleukin-2. As a result, we found that older dogs have a lower proliferative capacity of CD8+ T-cells and a reduction in the naïve subset in their peripheral blood. Further analysis showed that older dogs had attenuated proliferation of the effector and central memory subsets. These results indicate the importance of maintaining less differentiated subsets to expand CD8+ T-cells in dogs and provide helpful insight into the development of dog immune therapies that require T-cell expansion ex vivo.

Enhanced Systemic Antitumour Immunity by Hypofractionated Radiotherapy and Anti-PD-L1 Therapy in Dogs with Pulmonary Metastatic Oral Malignant Melanoma

Although immune checkpoint inhibitors (ICIs), such as the anti-programmed death-ligand 1 (PD-L1) antibody, have been developed for the treatment of canine malignant melanoma, desirable clinical efficacies have not been achieved. Recent studies in humans have suggested that radiation therapy (RT) combined with ICIs induces robust systemic antitumour immunity in patients with cancer. This study retrospectively examined the therapeutic efficacy of combination therapy (hypofractionated RT and anti-PD-L1 antibody [c4G12]) in dogs with pulmonary metastatic oral malignant melanoma. The intrathoracic clinical benefit rate (CBR)/median overall survival (OS) in the no RT (n = 20, free from the effect of RT), previous RT (n = 9, received RT ≤8 weeks prior to the first c4G12 dose), and concurrent RT (n = 10, c4G12 therapy within ±1 week of the first RT fraction) groups were 10%/185 days, 55.6%/283.5 days (p < 0.05 vs. no RT group), and 20%/129 days (p > 0.05 vs. no RT group), respectively. The adverse events were considered to be tolerable in the combination therapy. Thus, hypofractionated RT before the initiation of c4G12 therapy can be an effective approach for enhancing the therapeutic efficacy of immunotherapy, with acceptable safety profiles. Further prospective clinical studies are required to confirm the findings of this study.

Treatment outcome of local injection of botulinum toxin for claw toe: Differences between cerebral hemorrhage and infarction

BACKGROUND

Some patients with post-stroke claw toe respond well to botulinum toxin (BoNT) treatment while others do not. This study was designed to assess the impact of stroke type (cerebral hemorrhage and cerebral infarction) on the outcome of BoNT treatment for claw toe.

METHODS

We retrospectively examined the medical records of patients who received local BoNT (onabotulinumtoxin A) injections into the flexor hallucis longus (FHL) and flexor digitorum longus (FDL) muscles. All patients suffered stroke-related leg paralysis and spasticity.

RESULTS

The study participants were 58 patients (mean age, 61.4 ± 10.3 years, ± SD) with time since stroke of 6.7 ± 4.4 years. The stroke type was cerebral hemorrhage (n = 38) and cerebral infarction (n = 20). After a total of 124 BoNT administrations with medical records entries on the subjective symptoms, the odds for symptomatic improvement was approximately 5.8 times higher in patients of the infarction group compared with the hemorrhage group (OR = 5.787, 95% CI = 2.369-14.134, p = 0. 000). Fifty-one patients (32 with cerebral hemorrhage, 19 with cerebral infarction) received the first local BoNT injection and had available medical records, analysis of which showed a significantly higher rate of symptomatic improvement in patients of the infarction group than those of the hemorrhage group (p = 0.006). After adjustment by factors known to influence treatment outcome (degree of spasticity and paralysis, BoNT dosage, and extent of FDL muscle control of toe movements), the treatment effect was predominantly higher in patients with cerebral infarction.

CONCLUSION

The BoNT treatment response was better for claw toes in cerebral infarction patients than in hemorrhage patients, possibly suggesting that claw toe is associated with more severe spasticity in this group of patients.

Prevention of hypoglycemia by intermittent-scanning continuous glucose monitoring device combined with structured education in patients with type 1 diabetes mellitus: A randomized, crossover trial

AIMS

We conducted a randomized, crossover trial to compare intermittent-scanning continuous glucose monitoring (isCGM) device with structured education (Intervention) to self-monitoring of blood glucose (SMBG) (Control) in the reduction of time below range.

METHODS

This crossover trial involved 104 adults with type 1 diabetes mellitus (T1DM) using multiple daily injections. Participants were randomly allocated to either sequence Intervention/Control or sequence Control/Intervention. During the Intervention period which lasted 84 days, participants used the first-generation FreeStyle Libre (Abbott Diabetes Care, Alameda, CA, USA) and received structured education on how to prevent hypoglycemia based on the trend arrow and by frequent sensor scanning (≥10 times a day). Confirmatory SMBG was conducted before dosing insulin. The Control period lasted 84 days. The primary endpoint was the decrease in the time below range (TBR; <70 mg/dL).

RESULTS

The time below range was significantly reduced in the Intervention arm compared to the Control arm (2.42 ± 1.68 h/day [10.1 %±7.0 %] vs 3.10 ± 2.28 h/day [12.9 %±9.5 %], P = 0.012). The ratio of high-risk participants with low blood glucose index >5 was significantly reduced (8.6 % vs 23.7 %, P < 0.001).

CONCLUSIONS

The use of isCGM combined with structured education significantly reduced the time below range in patients with T1DM.

Molecular characterization of feline immune checkpoint molecules and establishment of PD-L1 immunohistochemistry for feline tumors

Spontaneous tumors are a major cause of death in cats. Treatment of human tumors has progressed dramatically in the past decade, partly due to the success of immunotherapies using immune checkpoint inhibitors, such as anti-programmed death 1 (PD-1) and anti-PD-ligand 1 (PD-L1) antibodies. However, little is known about the PD-1 pathway and its association with tumor disease in cats. This study investigated the applicability of anti-PD-1/PD-L1 therapy in feline tumors. We first determined the complete coding sequence of feline PD-L1 and PD-L2, and found that the deduced amino acid sequences of feline PD-L1/PD-L2 share high sequence identities (66-83%) with orthologs in other mammalian species. We prepared recombinant feline PD-1, PD-L1, and PD-L2 proteins and confirmed receptor-ligand binding between PD-1 and PD-L1/PD-L2 using flow cytometry. Next, we established an anti-feline PD-L1 monoclonal antibody (clone CL1Mab-7) to analyze the expression of PD-L1. Flow cytometry using CL1Mab-7 revealed the cell surface expression of PD-L1 in a feline macrophage (Fcwf-4) and five mammary adenocarcinoma cell lines (FKNp, FMCm, FYMp, FONp, and FONm), and showed that PD-L1 expression was upregulated by interferon-γ stimulation. Finally, immunohistochemistry using CL1Mab-7 also showed PD-L1 expression in feline squamous cell carcinoma (5/5, 100%), mammary adenocarcinoma (4/5, 80%), fibrosarcoma (5/5, 100%), and renal cell carcinoma (2/2, 100%) tissues. Our results strongly encourage further investigations of the PD-1/PD-L1 pathway as a potential therapeutic target for feline tumors.

Effects of Flexor Digitorum Longus Muscle Anatomical Structure on the Response to Botulinum Toxin Treatment in Patients with Post-Stroke Claw Foot Deformity

(1) Background: The purpose of this retrospective case-control study was to determine the relationship between the control of toe movements by flexor hallucis longus (FHL) and flexor digitorum longus (FDL) muscles and the response to treatment with botulinum toxin (BoNT) in post-stroke patients with claw toe. (2) Methods: Subjects with stroke-related leg paralysis/spasticity and claw toes received multiple injections of BoNT (onabotulinumtoxin A) into the FHL or FDL muscles. We investigated the relationship between the mode of transmission of FHL and FDL muscle tension to each toe (MCT) and treatment outcome using the data of 53 patients who received 124 injections with clinically recorded treatment outcome. We also dissected the potential variables that could determine the treatment outcome. (3) Results: The effectiveness of BoNT treatment was significantly altered by FDL-MCT (OR = 0.400, 95% CI = 0.162–0.987, p = 0.047). Analysis of the response to the first BoNT injection showed an odds ratio of FDL-MCT of approximately 6.0 times (OR = 0.168, 95% CI = 0.033–0.857, p = 0.032). The more tibial the influence of the FDL muscle on each toe, the better the treatment outcome on the claw toe. (4) Conclusions: The anatomic relation between FDL muscle and each toe seems to affect the response to treatment with BoNT in post-stroke patients with claw toes.

Fibroblast growth factor receptor 3 overexpression mediates ALK inhibitor resistance in ALK-rearranged non-small cell lung cancer

The rearrangement of anaplastic lymphoma kinase (ALK) occurs in 3%‐5% of patients with non–small cell lung cancer (NSCLC) and confers sensitivity to ALK–tyrosine kinase inhibitors (TKIs). For the treatment of patients with ALK‐rearranged NSCLC, various additional ALK‐TKIs have been developed. Ceritinib is a second‐generation ALK‐TKI and has shown great efficacy in the treatment of patients with both newly diagnosed and crizotinib (a first‐generation ALK‐TKI)‐refractory ALK‐rearranged NSCLC. However, tumors can also develop ceritinib resistance. This may result from secondary ALK mutations, but other mechanisms responsible for this have not been fully elucidated. In this study, we explored the mechanisms of ceritinib resistance by establishing ceritinib‐resistant, echinoderm microtubule‐associated protein‐like 4 (EML4)‐ALK–positive H3122 cells and ceritinib‐resistant patient‐derived cells. We identified a mechanism of ceritinib resistance induced by bypass signals that is mediated by the overexpression and activation of fibroblast growth factor receptor 3 (FGFR3). FGFR3 knockdown by small hairpin RNA or treatment with FGFR inhibitors was found to resensitize the resistant cells to ceritinib in vitro and in vivo. FGFR ligands from either human serum or fetal bovine serum were able to activate FGFR3 and induce ceritinib resistance. A detailed analysis of ceritinib‐resistant patient‐derived specimens confirmed that tyrosine‐protein kinase Met (cMET) amplification induces ceritinib resistance. Amplified cMET counteractivated EGFR and/or Her3 and induced ceritinib resistance. These results reveal multiple ceritinib resistance mechanisms and suggest that ceritinib resistance might be overcome by identifying precise resistance mechanisms.

Effects of combined one-lung ventilation and intrathoracic carbon dioxide insufflation on intrathoracic working space when performing thoracoscopy in dogs

OBJECTIVE

To evaluate the effects of combining one-lung ventilation and carbon dioxide insufflation (OLV-CDI) on intrathoracic working space (determined by means of CT) during thoracoscopy in dogs and investigate conditions that could safely improve working space compared with OLV alone.

ANIMALS

6 healthy Beagles.

PROCEDURES

Dogs were anesthetized, and right- or left-sided (n = 3/side) OLV was instituted. On the blocked side, a laparoscopic trocar sleeve was placed in the ninth intercostal space for CDI. CT was performed under 3 conditions: with OLV alone, with OLV-CDI at an intrapleural pressure (IPP) of 3 mm Hg, and with OLV-CDI at an IPP of 5 mm Hg. Working space volume (WSV), ventilation space volume (VSV), and thoracic cavity volume (TCV) were determined from CT images.

RESULTS

With OLV-CDI at an IPP of 3 or 5 mm Hg, WSV and TCV were significantly increased, compared with values obtained during OLV alone. With OLV-CDI at an IPP of 5 mm Hg, VSV and Spo2 were significantly decreased, compared with values obtained during OLV alone. Additionally, contralateral pneumothorax was observed in 4 dogs at an IPP of 5 mm Hg.

CLINICAL RELEVANCE

Combining OLV and CDI could provide a larger working space than OLV alone, even with an IPP of 3 mm Hg, in dogs of limited size. However, an evaluation of the effects on oxygenation and cardiovascular variables is needed before clinical use.

Targeting Podoplanin for the Treatment of Osteosarcoma

PURPOSE

Osteosarcoma, the most common bone malignancy in children, has a poor prognosis, especially when the tumor metastasizes to the lungs. Therefore, novel therapeutic strategies targeting both proliferation and metastasis of osteosarcoma are required. Podoplanin (PDPN) is expressed by various tumors and is associated with tumor-induced platelet activation via its interaction with C-type lectin-like receptor 2 (CLEC-2) on platelets. We previously found that PDPN contributed to osteosarcoma growth and metastasis through platelet activation; thus, in this study, we developed an anti-PDPN humanized antibody and evaluated its effect on osteosarcoma growth and metastasis.

EXPERIMENTAL DESIGN

Nine osteosarcoma cell lines and two osteosarcoma patient-derived cells were collected, and we evaluated the efficacy of the anti-DPN-neutralizing antibody PG4D2 and the humanized anti-PDPN antibody AP201, which had IgG4 framework region. The antitumor and antimetastasis effect of PG4D2 and AP201 were examined in vitro and in vivo. In addition, growth signaling by the interaction between PDPN and CLEC-2 was analyzed using phospho-RTK (receptor tyrosine kinase) array, growth assay, or immunoblot analysis under the supression of RTKs by knockout and inhibitor treatment.

RESULTS

We observed that PG4D2 treatment significantly suppressed tumor growth and pulmonary metastasis in osteosarcoma xenograft models highly expressing PDPN. The contribution of PDGFR activation by activated platelet releasates to osteosarcoma cell proliferation was confirmed, and the humanized antibody, AP201, suppressed in vivo osteosarcoma growth and metastasis without significant adverse events.

CONCLUSIONS

Targeting PDPN with a neutralizing antibody against PDPN-CLEC-2 without antibody-dependent cell-mediated cytotoxicity and complement-dependent cytotoxicity is a novel therapeutic strategy for PDPN-positive osteosarcoma.

Exploration of serum biomarkers in dogs with malignant melanoma receiving anti-PD-L1 therapy and potential of COX-2 inhibition for combination therapy

Immune checkpoint inhibitors (ICIs) such as anti-PD-L1 antibodies are widely used to treat human cancers, and growing evidence suggests that ICIs are promising treatments for canine malignancies. However, only some canine oral malignant melanoma (OMM) cases respond to ICIs. To explore biomarkers predictive of survival in dogs with pulmonary metastatic OMM receiving the anti-PD-L1 antibody c4G12 (n = 27), serum concentrations of prostaglandin E2 (PGE2), cytokines, chemokines, and growth factors were measured prior to treatment initiation. Among 12 factors tested, PGE2, interleukin (IL)-12p40, IL-8, monocyte chemotactic protein-1 (MCP-1), and stem cell factor (SCF) were higher in OMM dogs compared to healthy dogs (n = 8). Further, lower baseline serum PGE2, MCP-1, and vascular endothelial growth factor (VEGF)-A concentrations as well as higher IL-2, IL-12, and SCF concentrations predicted prolonged overall survival. These observations suggest that PGE2 confers resistance against anti-PD-L1 therapy through immunosuppression and thus is a candidate target for combination therapy. Indeed, PGE2 suppressed IL-2 and interferon (IFN)-γ production by stimulated canine peripheral blood mononuclear cells (PBMCs), while inhibition of PGE2 biosynthesis using the COX-2 inhibitor meloxicam in combination with c4G12 enhanced Th1 cytokine production by PBMCs. Thus, serum PGE2 may be predictive of c4G12 treatment response, and concomitant use of COX-2 inhibitors may enhance ICI antitumor efficacy.

Screening of bacterial DNA in bile sampled from healthy dogs and dogs suffering from liver- or gallbladder-associated disease

Although the biliary system is generally aseptic, gallbladder microbiota has been reported in humans and some animals apart from dogs. We screened and analyzed the bacterial deoxyribonucleic acid in canine gallbladders using bile sampled from 7 healthy dogs and 52 dogs with liver- or gallbladder-associated disease. PCR screening detected bacteria in 17.3% of diseased dogs (9/52) and none in healthy dogs. Microbiota analysis of PCR-positive samples showed that the microbial diversity differed between liver- and gallbladder-associated disease groups. Thus, a specific bacterial community appears to occur at a certain frequency in the bile of diseased dogs.

GSK3 inhibition circumvents and overcomes acquired lorlatinib resistance in ALK-rearranged non-small-cell lung cancer

Anaplastic lymphoma kinase (ALK) fusion is found in ~3%–5% of patients with non-small-cell lung cancers (NSCLCs). Although the third-generation ALK tyrosine kinase inhibitor (TKI) lorlatinib shows high clinical efficacy in ALK-positive NSCLC, most of the patients eventually relapse with acquired resistance. Recently, drug-tolerant persister (DTP) cells have been considered an important seed of acquired resistance cells. In this study, we established lorlatinib intermediate resistant cells from a patient-derived cell model. Glycogen synthase kinase 3 (GSK3) inhibitions significantly suppressed lorlatinib intermediate resistant cell growth. GSK3 inhibition also sensitized acquired resistance cells derived from alectinib-treated patients with or without secondary mutations to lorlatinib. Therefore, GSK3 plays a crucial role in developing acquired resistance against lorlatinib in ALK-positive NSCLC mediated by lorlatinib intermediate resistant cells and could be a potential molecular target to prevent acquired lorlatinib resistance and overcome ALK-TKI resistance.

Computed angiographic variations in hepatic venous vasculature in dogs

OBJECTIVE

To identify the number of hepatic veins draining directly or indirectly into the caudal vena cava Thank you (CVC) using computed tomography angiography (CTA) in dogs.

STUDY DESIGN

Retrospective clinical study.

ANIMALS

Client-owned dogs (n = 77).

METHODS

Abdominal CTA images were analyzed. Retrospective convenience sampling was performed using archived clinical cases to determine the number of hepatic veins in each liver lobe.

RESULTS

A median of 2 vessels from the right lateral lobe (range: 1-4) and the caudate process of the caudate lobe (range: 1-5) drained directly into the CVC. In the quadrate lobe, most common patterns consisted of 1 vessel directly draining to the CVC or indirectly via the left hepatic vein (LHV), and a vessel from quadrate lobe and right medial lobe merging into 1 vessel draining into the CVC or the LHV. A median of 3 vessels in the left lateral lobe (range: 2-8) and a median of 1 vessel in the left medial lobe (range: 1-3) drained into the LHV. In the papillary process of the caudate lobe, a median of 1 (range: 1-2) vessel drained directly into the CVC or the LHV.

CONCLUSION

The draining pattern of hepatic veins varied widely in all liver lobes, especially the left lateral liver lobe.

CLINICAL SIGNIFICANCE

Veterinary surgeons should consider the potential presence of multiple hepatic veins and their draining pattern when performing hilar liver lobe resection. Attentive evaluation of a preoperative CTA is recommended for surgical planning.