Evaluation of the fatty acid-based erythrocyte membrane lipidome in cats with food responsive enteropathy, inflammatory bowel disease and low-grade intestinal T-cell lymphoma.

Feline chronic enteropathies (FCE), include food-responsive-enteropathy (FRE), inflammatory bowel disease (IBD), and low-grade intestinal T-cell lymphoma (LGITL), and are common causes of chronic gastrointestinal signs in cats. Distinguishing between different subgroups of FCE can be challenging due to the frequent overlap of anamnestic, clinical, and laboratory data. While dysregulation in lipid metabolism has been reported in humans and dogs with chronic IBD, similar changes in cats are not yet completely understood. Assessing the fatty acid (FA) profile of red blood cell (RBC) membranes offers a valuable method for evaluating the quantity and quality of structural and functional molecular components in the membranes. Therefore, this study aimed to examine the FA composition of RBC membranes in FCE in comparison to healthy cats (HC). Gas-chromatography was used to quantitatively analyze a cluster of 11 FA, and based on these results, parameters of lipid homeostasis and enzyme activity indexes were calculated. A total of 41 FCE cats (17 FRE, 15 IBD, 9 LGITL) and 43 HC were enrolled. In FCE cats, the values of docosapentaenoic acid (p = 0.0002) and docosahexaenoic acid (p = 0.0246), were significantly higher, resulting in an overall increase in ω-3 polyunsaturated fatty acids (PUFA) (p = 0.006), and that of linoleic acid (p = 0.0026) was significantly lower. Additionally, FCE cats exhibited an increased PUFA balance (p = 0.0019) and Δ6-desaturase index (p = 0.0151), along with a decreased ω-6/ω-3 ratio (p = 0.0019). No differences were observed among cats affected by FRE, IBD and LGITL. Like humans and dogs, the results of this study indicate that FCE cats also display changes in their FA lipid profile at the level of the RBC membrane. The non-invasive analysis of RBC membrane shows promise as a potential tool for gaining a better understanding of lipid imbalances in this disease.

Vinorelbine as First-Line Treatment in Stage IV Canine Primary Pulmonary Carcinoma.

Vinorelbine (VRL), a semi-synthetic vinca alkaloid commonly used in humans with advanced lung cancer, reaches high concentrations in the lung tissue, has proven antineoplastic activity and a low toxicity profile in dogs. Treatment-naïve, client-owned dogs with a cyto/histological diagnosis of advanced pulmonary carcinoma, selected from a laboratory database and previously subjected to imaging, were enrolled in the study. Vinorelbine (15 mg/m2) was administered weekly for 4 weeks and then fortnightly until progressive disease was documented. Staging work-up was repeated by means of diagnostic imaging after the fourth VRL (i.e., 28 days) and monthly thereafter; response to treatment was evaluated according to the RECIST. Toxicity was graded following the VCOGC group. Ten dogs met the inclusion criteria. Partial response was documented in eight dogs. Median time to progression was 88 days (range: 7-112) and median survival time for all dogs was 100 days (range 7-635). The most common side effect was neutropenia. The main limitations of the study were the absence of histological diagnosis in eight cases and the limited number of treated dogs. VRL is well tolerated with an adequate toxicity profile and may be useful in the management of advanced lung tumours if used as a first-line treatment strategy.

Unusual tongue metastasis from lung adenocarcinoma in a cat with feline lung-digit syndrome.

This report describes the pathological findings in a 15-year-old spayed female Domestic Shorthaired cat with a pulmonary adenocarcinoma characterized by feline lung-digit syndrome (FLDS) and unusual tongue metastasis. Felis catus papillomavirus type 3 (FcaPV-3) DNA was amplified from the lingual sample but not from samples of the pulmonary mass or digital or splenic metastatic lesions, indicating the presence of FcaPV-3 in the oral cavity but not suggesting a role for FcaPVs in tumour pathogenesis. FLDS is a clinical entity in which primary lung tumours present because of metastatic digital lesions. In humans, tongue metastasis may be a rare initial presentation of lung cancer, whereas, to the best of our knowledge, tongue metastasis of feline tumours has not been reported. Although lingual metastases are rare, the present findings serve to remind clinicians that metastatic manifestations of primary lung tumours in cats may involve multiple extrapulmonary sites, including the tongue.

Expression of cannabinoid receptors CB1 and CB2 in canine cutaneous mast cell tumours.

Cannabinoid receptors (CB1 and CB2) belong to endocannabinoid system (ECS), which is also composed from endocannabinoids and the enzymatic systems involved in their biosynthesis and degradation. The expression of CB1 and CB2 have been previously identified in normal canine mast cell and in atopic dermatitis. Canine cutaneous mast cell tumours (cMCTs) are among the most common cutaneous neoplasms in dogs and have a highly variable clinical behaviour. Expression of CB1-CB2 was assessed by means of immunohistochemistry in thirty-seven dogs (from 2019 to 2021) with proven histological diagnosis of cMCT. Dogs were divided in two groups according to the Kiupel's grading system: high-grade (HG) cMCT and low-grade (LG) cMCT. A semiquantitative (score 0-3) and quantitative assessment of immunoreactivity (IR) was performed for each case. Our results show that there CB1 and CB2 are highly expressed in LG- cMCT, in contrast to HG- cMCT.

The Role of Fine Needle Aspiration of Liver and Spleen in the Staging of Low-Grade Canine Cutaneous Mast Cell Tumor.

Clinical staging is a fundamental step in the clinical assessment of canine cutaneous mast cell tumor (cMCT), and it is recommended to evaluate the tumor draining lymph node (eTDLN), perform diagnostic imaging, and fine needle aspiration (FNA) of the spleen and liver to determine the presence of metastatic disease, thereby refining the prognosis. The aim of this retrospective study was to evaluate the prevalence of splenic and hepatic involvement in newly diagnosed canine low-grade cMCT (Patnaik grade I-II, Kiupel low-grade). Medical records of dogs that underwent a clinical staging work-up and surgical excision for a low-grade cMCT between December 2019 and December 2021 were reviewed at five veterinary centers. Only dogs with a histological diagnosis of low-grade cMCT, FNA or histology of the eTDLN, FNA of the spleen and liver, and one year of follow up were included. One hundred and thirty-six dogs met the inclusion criteria. Only 1 out of 136 dogs (0.7%) had the presence of visceral metastases at diagnosis, suggesting that the prevalence of visceral metastases in low-grade cMCT is extremely low. The results of this study are consistent with previous literature and suggest that after a diagnosis of low-grade cMCT, cytology of visceral organs may not represent an essential step in the clinical staging work-up.

Transnasal Endoscopic Approach for Osteoid Osteoma of the Odontoid Process in a Child: Technical Note and Systematic Review of the Literature.

Osteoid osteoma (OO) is a primary benign tumor that accounts for up to 3% of all bone tumors. The cervical spine is less affected by OOs, and very few cases of C2 OOs have been reported in the literature, both in adults and children. Surgery may be required in case of functional torticollis, stiffness, and reduced range of motion (ROM) due to cervical OOs refractory to medical therapy. Several posterior and anterior surgical techniques have been described to remove C2 OOs. In particular, anterior approaches to the cervical spine represent the most used surgical route for treating C2 OOs. We describe the first case of OO of the odontoid process removed through a transnasal endoscopic approach with the aid of neuronavigation in a 6-year-old child. No intraoperative complications occurred, and the post-operative course was uneventful. The patient had immediate relief of neck pain and remained pain-free throughout the follow-up period, with complete functional recovery of the neck range of motion (ROM). In this case, based on the favorable anatomy, the transnasal endoscopic approach represented a valuable strategy for the complete removal of an anterior C2 OO without the need for further vertebral fixation since the preservation of ligaments and paravertebral soft tissue.

Detection and Characterization of Feline Calicivirus Associated with Paw and Mouth Disease.

Feline calicivirus (FCV) infection in cats can led to several diverse clinical presentations, ranging from mild upper respiratory signs to virulent systemic disease. Herein, we report a paw and mouth disease case in a 7-year-old household cat due to an FCV infection. An asymptomatic cat living in the same household was also infected with FCV. Clinical and pathological investigations were combined with the molecular and phenotypical characterization of the FCV strains. The RNA of the FCV was detected using qualitative and quantitative reverse transcription (RT)-PCR assays, and FCV antigen was confirmed by immunohistochemistry. After the whole genome analysis, the strains detected in the two cats appeared to be genetically diverse from FCVs previously detected in association with paw and mouth disease and with virulent systemic disease. Interestingly, the isolates obtained in this study were resistant to low pH conditions and slightly susceptible to bile salts, but they were susceptible to a trypsin treatment, revealing a phenotype pattern that is different from that which has been observed for respiratory FCVs.

Sentinel Lymph Node Mapping with Indirect Lymphangiography for Canine Mast Cell Tumour.

Mast cell tumour (MCT) is a common cutaneous and subcutaneous neoplasia in dogs. It can metastasise to lymph nodes (LNs), and this adversely affects the prognosis and treatment. The study aims to evaluate the SLN mapping of MCTs with radiographic indirect lymphography. Dogs that underwent clinical staging were prospectively enrolled. Lipiodol was injected around the MCT or the surgical scar. After 24 h, LNs that picked up contrast were radiographically assessed. Twenty-six dogs with 29 MCTs were included. MCTs were confirmed histologically, while SLNs were evaluated either by cytology and/or histology. SLNs were detectable in 23 dogs with 26 MCTs. Lymphatic vessels were visible in 19 MCTs. In nine MCTs, at least two SLNs picked up contrast. In particular, seven MCTs involved two SLNs, and two MCTs involved three different SLNs. In nine MCTs, at least a SLN was metastatic. This study indicates that the lymph drainage pattern of the MCTs may be different for each MCT, and more than one SLN can be involved. Indirect lymphangiography with Lipiodol allowed the detection of the SLN in 90% of MCTs. This provided clinically relevant information to remove the LN and stage the patient.

Comparison of the binding and internalization properties of 12 DOTA-coupled and ¹¹¹In-labelled CCK2/gastrin receptor binding peptides: a collaborative project under COST Action BM0607.

PURPOSE: Specific overexpression of cholecystokinin 2 (CCK2)/gastrin receptors has been demonstrated in several tumours of neuroendocrine origin. In some of these cancer types, such as medullary thyroid cancer (MTC), a sensitive diagnostic modality is still unavailable and therapeutic options for inoperable lesions are needed. Peptide receptor radionuclide therapy (PRRT) may be a viable therapeutic strategy in the management of these patients. Several CCK2R-targeted radiopharmaceuticals have been described in recent years. As part of the European Union COST Action BM0607 we studied the in vitro and in vivo characteristics of 12 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA)-conjugated CCK2R binding peptides. In the present study, we analysed binding and internalization characteristics. Stability, biodistribution and imaging studies have been performed in parallel by other centres involved in the project. METHODS: Determination of IC(50) values was performed using autoradiography, with DOTA-peptides displacing (125)I-CCK from receptors on tissue sections from human tumours. Saturation binding and internalization experiments were performed using (111)In-labelled peptides. The rat AR42J cell line and the human A431-CCK2R transfected cell line were utilized for in vitro experiments; dissociation constants (K(d)) and apparent number of binding sites (B(max)) were determined. Internalization was determined in receptor-expressing cells by incubating with tracer amounts of peptide at 37 and 4°C for different times up to 120 min. Surface-bound peptide was then stripped either by acid wash or subsequent incubation with 1 µM unlabelled peptide at 4°C. RESULTS: All peptides showed high receptor affinity with IC(50) values ranging from 0.2 to 3.4 nM. Saturation experiments also showed high affinity with K(d) values in the 10(-9)-10(-8) M range. B(max) values estimated in A431-CCK2R cells ranged from 0.6 to 2.2 × 10(6) per cell. All peptides showed high levels of internalization when incubated at 37°C. CONCLUSION: All DOTA-conjugated peptides showed high receptor binding and internalization properties and appear suitable for further characterization, as described in other articles of this issue.

Comparison of three PCR assays for the evaluation of interferon-beta biological activity in patients with multiple sclerosis.

BACKGROUND: The gene expression of the myxovirus-resistant protein A (MxA) gene is a sensitive measure of the biological response of therapeutically applied interferon-beta (IFNbeta) and of its reduced bioavailability due to inhibiting factors such as IFNbeta-induced neutralizing antibodies (NAbs). METHODS: We compared three methods for MxA mRNA quantification in 826 peripheral blood mononuclear cell (PBMC) samples obtained from patients with multiple sclerosis (MS). MxA mRNA measurements were performed using quantitative-competitive (qc)-PCR, real time-PCR, and the new semi-quantitative (sq)-PCR assay (MxA IBRIDOGEN). RESULTS: According to the treatment status (untreated samples versus NAb-negative treated samples), real time-PCR gave the highest specificity (93%). Slightly lower specificities were obtained with qc-PCR and sq-PCR (both 91%). qc-PCR showed the highest sensitivity (97%) compared with both real time-PCR (94%) and sq-PCR (95%). A positive correlation was found between qc-PCR and real time-PCR measurements (rspearman=0.776; p<0.0001), which also showed 90% agreement based on a statistically calculated threshold. Likewise, sq-PCR evaluations showed 84% and 79% agreement with qc-PCR and real time-PCR measurements, respectively. In addition, we showed a concordance of 89% between three sq-PCR kits. CONCLUSIONS: All three methods displayed high specificity for MxA gene expression analysis, allowing the detection of patients in whom IFNbeta did not have any biological action. qc-PCR and real time-PCR are both useful during clinical trials demanding quantitative data of biological activity, whereas sq-PCR could prove useful for routine screening purposes because it is easy to perform and can be done in not specialized laboratories.

Assessment of bone marrow infiltration diagnosed by flow cytometry in canine large B cell lymphoma: prognostic significance and proposal of a cut-off value.

The aims of this study were to assess the prognostic significance of bone marrow (BM) infiltration in canine large B cell lymphoma (LBCL) and to establish cut-off values for designating the BM as infiltrated by lymphoid blasts. The degree of BM infiltration by large CD21 positive cells in dogs with LBCL was assessed by flow cytometry (FC) and related to time to progression (TTP) and lymphoma-specific survival (LSS). Forty-six dogs were prospectively enrolled, staged and treated with a dose-intense chemotherapeutic protocol. BM infiltration was directly correlated with peripheral blood infiltration (P=0.001), high lactate dehydrogenase activity (P=0.0024) and substage b disease (P<0.001). In the univariate analysis, there was a significant association between BM infiltration diagnosed by FC and both TTP (P=0.001) and LSS (P<0.001). Substage was the only factor associated with TTP in the multivariate analysis (P=0.002), whereas substage (P<0.001) and anaemia (P=0.008) were associated with LSS. A cut-off of 3% BM infiltration had the strongest prognostic value, since it discriminated between dogs with a poorer prognosis (median TTP 69 days; median LSS 155 days) and dogs with a better prognosis (median TTP 149 days; median LSS 322 days). BM analysis is an essential step in the staging of LBCL. The presence of BM infiltration by FC at diagnosis is a negative prognostic indicator in canine LBCL.

Noninvasive repetitive imaging of somatostatin receptor 2 gene transfer with positron emission tomography.

Noninvasive in vivo imaging of gene expression is desirable to monitor gene transfer in both animal models and humans. Reporter transgenes with low endogenous expression levels are instrumental to this end. The human somatostatin receptor 2 (hSSTR2) has low expression levels in a variety of tissues, including muscle and liver. We tested the possibility of noninvasively and quantitatively monitoring hSSTR2 transgene expression, following adeno-associated viral (AAV) vector-mediated gene delivery to murine muscle and liver by positron emission tomography (PET) using (68)gallium-DOTA-Tyr(3)-Thr(8)-octreotate ((68)Ga-DOTATATE) as a highly specific SSTR2 ligand. Repetitive PET imaging showed hSSTR2 signal up to 6 months, which corresponds to the last time point of the analysis, after gene delivery in both transduced tissues. The levels of tracer accumulation measured in muscle and liver after gene delivery were significantly higher than in control tissues and correlated with the doses of AAV vector administered. As repetitive, quantitative, noninvasive imaging of AAV-mediated SSTR2 gene transfer to muscle and liver is feasible and efficient using PET, we propose this system to monitor the expression of therapeutic genes coexpressed with SSTR2.