Photodynamic therapy of feline cutaneous squamous cell carcinoma using a newly developed liposomal photosensitizer: preliminary results concerning drug safety and efficacy

BACKGROUND: Squamous cell carcinomas are common skin tumors in cats. We investigated photodynamic therapy (PDT) using a new liposomal photosensitizer as a minimally invasive, effective treatment that can be easily performed while achieving good cosmetic results. AIM: The goal of this study was to assess and describe possible toxicities using a liposomal formulation of the photosensitizer meta-(Tetrahydroxyphenyl)Chlorin (m-THPC) and investigate if favorable pharmacokinetics translate into favorable tumor response and control. ANIMALS: Eighteen client-owned cats with 20 spontaneous cutaneous squamous cell carcinomas were included in the study. METHODS: PDT was performed using a new, liposomal formulation of the photosensitizer. Toxicity, tumor response, and tumor control were evaluated retrospectively. RESULTS: No general adverse effects were observed in cats treated with the new liposomal formulation. Mild local toxicity such as erythema and edema were seen in 15% of the patients. All cats responded to therapy, with a complete response rate of 100%. The overall 1-year control rate was 75%. The tumor recurrence rate was 20% with a median time to recurrence of 172.25 +/-87.1) days. CONCLUSIONS AND CLINICAL IMPORTANCE: A new liposomal photosensitizer was successfully used for squamous cell carcinoma in cats and was well tolerated. There were no systemic adverse effects observed with the liposomal formulation. The favorable pharmacokinetics of the liposomal drug resulted in a favorable tumor response.     

Extracellular heat shock protein 70 levels in tumour-bearing dogs and cats treated with radiation therapy and hyperthermia

Hyperthermia is a form of a cancer treatment which is frequently applied in combination with radiotherapy (RT) to improve therapy responses and radiosensitivity. The mode of action of hyperthermia is multifactorial; the one hand by altering the amount of the blood circulation in the treated tissue, on the other hand by modulating molecular pathways involved in cell survival processes and immunogenic interactions. One of the most dominant proteins induced by hyperthermia is the major stress-inducible heat shock protein 70 (Hsp70). Hsp70 can be found in the blood either as a free-protein (free HSP70) derived from necrotic cells, or lipid-bound (liposomal Hsp70) when it is actively released in extracellular vesicles (EVs) by living cells. The aim of the study was to evaluate the levels of free and liposomal Hsp70 before and after treatment with RT alone or hyperthermia combined with radiotherapy (HTRT) in dogs and cats to evaluate therapy responses. Peripheral blood was collected from feline and canine patients before and at 2, 4, 6 and 24 h after treatment with RT or HTRT. Hsp70 enzyme-linked immunosorbent assays (ELISAs) were performed to determine the free and liposomal Hsp70 concentrations in the serum. The levels were analysed after the first fraction of radiation to study immediate effects and after all applied fractions to study cumulative effects. The levels of free and liposomal Hsp70 levels in the circulation were not affected by the first singular treatment and cumulative effects of RT in cats however, after finalizing all treatment cycles with HTRT free and liposomal Hsp70 levels significantly increased. In dogs, HTRT, but not treatment with RT alone, significantly affected liposomal Hsp70 levels during the first fraction. Free Hsp70 levels were significantly increased after RT, but not HTRT, during the first fraction in dogs. In dogs, on the other hand, RT alone resulted in a significant increase in liposomal Hsp70, but HTRT did not significantly affect the liposomal Hsp70 when cumulative effects were analysed. Free Hsp70 was significantly induced in dogs after both, RT and HTRT when cumulative effects were analysed. RT and HTRT treatments differentially affect the levels of free and liposomal Hsp70 in dogs and cats. Both forms of Hsp70 could potentially be further investigated as potential liquid biopsy markers to study responses to RT and HTRT treatment in companion animals.     

Cerebellar cortical abiotrophy in American Staffordshire terriers: clinical and pathological description of 3 cases

Three American Staffordshire Terriers were presented with gait abnormalities and loss of balance at the age of 4.5 (female) and 6 years (2 males). The onset varied between 3 and 5 years of age and the clinical signs were slowly progressive. The neurological examination revealed symmetrical generalized cerebellar ataxia with hypermetria, stiffness, and loss of balance with no evidence of paresis. The menace reflex was decreased in one dog and absent in another. A positional nystagmus was found in two dogs. The dogs were euthanized and a histopathological examination of each brain was performed. Pathological changes were confined to the cerebellum. The main finding was loss of Purkinje cells, as well as depletion of granular cell bodies and shrinkage of the granular and molecular cell layer. These findings are consistent with cerebellar cortical abiotrophy. A genetic basis is supposed, but the mode of inheritance is not determined yet. In contrast to some spinocerebellar ataxias in humans, the cause of Purkinje cell degeneration in cerebellar cortical abiotrophy of dogs is not known.     

Intracranial astrocytomas in eight cats: clinical and pathological findings

Intracranial astrocytomas are rarely diagnosed in cats. Clinical and pathological aspects of these tumors are more often described in humans and dogs. The classification scheme used in human medicine is of important prognostic value. We have analyzed clinical neurological and pathological findings from 8 cats with intracranial astrocytomas. The animals were 10.1 years old in average and presented with a history of tetraparesis (n = 3), epilepsy (n = 2), loss of balance (n = 3) and dyspnoe (n = 1). The latter cat died immediately after the first presentation while the other animals were euthanized because of a progressive course of the symptoms despite therapy. Even though feline astrocytomas, that we could classify into 4 different types in this study, are clinically and pathologically well correlated with those of other species, a prognostically useful classification has never been established before.     

牦牛大肠埃希氏菌病灭活疫苗的制备

用本实验室分离鉴定的致病性牦牛大肠埃希氏菌，按常规方法制备了4批氢氧化铝胶灭活疫苗。对牦牛大肠埃希氏菌的菌液培养、纯粹检验、活菌计数、灭活等进行了探索，并对用该菌研制成的疫苗进行了常规检验。结果4批灭活疫苗经无菌检验为阴性；经物理性状检验为：静置后上层是淡黄色的澄明液体，下层为灰白色沉淀，振荡后呈均匀混浊液；经牦牛安全检验结果为安全；经牦牛效力试验有效。牦牛大肠埃希氏菌病灭活疫苗为免疫预防该病打下了良好的基础。     

评估调质时间和温度对猪颗粒饲料淀粉糊化度和维生素沉积的影响

本论文研究了饲料加工的两个关键参数(调质温度和时间)对育肥猪颗粒饲料淀粉糊化度和维生素沉积的影响。日粮配方为含30%干酒糟及其可溶物的玉米-豆粕型基础日粮。整个试验中配方保持不变。本试验采用2×3双因子设计,调质温度分别为77℃和88℃,调质时间分别15秒、30秒和60秒。此外,本试验还设置一个对照组,对照组饲料不采用调质制粒工艺,而是采用粉料饲喂。因此,本试验共有7个处理组。采集调质后制粒前(热干粉)、制粒后冷却前(热制粒)、以及制粒冷却后(冷制粒)的样品,并分析这三种样品的总淀粉率、淀粉糊化     

MALDI‐MS Lipid Profiles of Oocytes Recovered by Ovum Pickup from Bos indicus and 1/2 indicus × taurus with High vs Low Oocyte Yields

The aim of the present study was to compare the lipid profile in oocytes of indicus and 1/2 indicus × taurus cows with high and low antral follicle count (AFC)/oocyte yields. After an OPU procedure (D0), antral follicles ≥3 mm were counted by ultrasonography (D4, 19, 34, 49, 64), and cows were assigned to groups with either high AFC (≥30 follicles; indicus, NH group; 1/2 indicus × taurus, AH group) or low AFC (≤15 antral follicles; indicus, NL group; 1/2 indicus × taurus, AL group). The lipid profiles of the oocytes were determined by MALDI‐MS. For GI, GII and GIII oocytes, the indicus samples tend to cluster separately from the 1/2 indicus × taurus samples. The lipid species [PC (P‐38:5) + H]⁺ and/or [PC (P‐36:2) + Na]⁺, [PC (38:2) + H]⁺, [PC (38:5) + Na]⁺ and [TAG (60:8) + NH⁴]⁺ were more abundant in indicus (NH and NL groups) than 1/2 indicus × taurus. The higher lipid content in the indicus oocytes likely reflects differences in the rate of lipid metabolism and may contribute to oocyte competence and embryo development.