Seropositivity and risk factors of Toxocara canis infection in adult asthmatic patients.

This cross-sectional study involving 86 adult asthmatic patients aimed to determine the relationship between Toxocara seropositivity and severity of asthma in adult asthmatics and investigate the risk factors for Toxocara infection. In all cases, T. canis IgG level was measured using an anti-Toxocara IgG enzyme-linked immunosorbent assay kit. Total serum IgE and eosinophil count were also determined. The anti-Toxocara IgG seropositivity was 68.6% among asthmatic patients. There were no statistically significant associations between Toxocara seroprevalence and other risk factors, clinical symptoms of asthma and high level of total serum IgE and eosinophilia. Pet ownership could be an important risk factor for Toxocariasis. Having a pet at home and wheezing were significantly associated with Toxocara seropositivity in adult asthmatic patients.

Application of 18F-FDG PET-CT in the management of pulmonary nodule and mass - a pictorial review.

BACKGROUND: Lung cancer is one of the leading causes of cancer-related mortality worldwide. Pulmonary nodules are commonly encountered in clinical practice because of the recent implementation of low-dose CT lung screening programme, incidental finding on cardiac CT or CT for nonthoracic related disease. 18F-FDG PET-CT plays an important role in the management of pulmonary nodules. METHODS: In this pictorial review, we present six different scenarios of using 18F-FDG PET-CT in the management of suspicious pulmonary nodule or mass. The advantages and limitations of 18F-FDG PET-CT and Herder model are discussed. RESULTS: 18F-FDG PET-CT with risk assessment using Herder model provides added value in characterising indeterminate pulmonary nodules. Besides, 18F-FDG PET-CT is valuable to guide the site of biopsy and provide accurate staging of lung cancer. CONCLUSION: To further improve its diagnostic accuracy, careful history taking, and CT morphological evaluation should be taken into consideration when interpreting 18FFDG PET-CT findings in patients with these nodules.

Which dogs with appendicular osteosarcoma benefit most from chemotherapy after surgery? Results from an individual patient data meta-analysis.

Osteosarcoma (OS) is a malignant tumor of mesenchymal origin that produces osteoid. Given that the prognosis can vary considerably between dogs, we aimed to explore whether treatment could be tailored towards patient subgroups, characterized by their predicted risk of mortality. For the current study, a subset of five nonrandomized studies (400 subjects of whom 88 were dead at 5 months follow-up) was used from a previously published 20 study individual patient data meta-analysis. Missing data was dependent on observed variables and was imputed to correct for this dependency. Based on a previously published multivariable prognostic model, the 5-month mortality risk was predicted. Subsequently, in surgically treated dogs, using a logistic regression model with a random intercept for a study indicator, we explored whether chemotherapy effectiveness depended on predicted 5-month mortality risk. After adjustment for potential confounders the main effect of any chemotherapy was 0.48 (odds ratio) (95%CI 0.30; 0.78). Testing for chemotherapy by predicted 5-month mortality risk interaction revealed that the effects of any chemotherapy decreased with increasing predicted risk; interaction OR 3.41 (1.07; 10.84). Results from individually comparing carboplatin, cisplatin, doxorubicin and doxorubicin combination therapy to no chemotherapy, were similar in magnitude and direction. These results indicate that the main treatment effects of chemotherapy do not necessarily apply to all patients.

In vitro effects of Yunnan Baiyao on canine hemangiosarcoma cell lines.

Yunnan Baiyao is a Chinese herbal medicine that has been utilized for its anti-inflammatory, haemostatic, wound healing and pain relieving properties in people. It has been utilized in the veterinary profession to control bleeding in dogs with hemangiosarcoma (HSA) and has been anecdotally reported to prolong survival times in dogs with this neoplasm. This study evaluated the in vitro activity of Yunnan Baiyao against three canine HSA cell lines after treatment with increasing concentrations of Yunnan Baiyao (50, 100, 200, 400, 600 and 800 µg mL(-1) ) at 24, 48 and 72 h. Mean half maximum inhibitory concentration (IC50 ) at 72 h for DEN, Fitz, SB was 369.9, 275.9 and 325.3 µg mL(-1) , respectively. Caspase-3/7 activity increased in correlation with the IC50 in each cell line which was confirmed by the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL, APO-BRDU Kit; BD Biosciences, San Jose, CA, USA) assay. VEGF in cell supernatant was also quantified. Overall, the study found that Yunnan Baiyao causes dose and time dependent HSA cell death through initiation of caspase-mediated apoptosis, which supports future studies involving Yunnan Baiyao.

In vitro effects of the tyrosine kinase inhibitor, masitinib mesylate, on canine hemangiosarcoma cell lines.

This study evaluated the in vitro activity of masitinib mesylate against canine hemangiosarcoma (HSA) cell lines after treatment with increasing concentrations of masitinib mesylate (0.01-100 µM) for 24, 48 and 72 h. Results indicated that masitinib mesylate caused a dose- and time-dependent decrease in HSA cell proliferation. The 50% inhibitory concentration (IC(50) ) at 72 h for three HSA cell lines (DEN, Fitz and SB) was found to be 8.56, 9.41 and 10.65 µM, respectively. Further investigation demonstrated that masitinib mesylate induced apoptosis in all HSA cell lines, including activation of caspase-3/7. Measurement of VEGF levels in cell supernatant found a statistically significant increased VEGF in close proximity to the IC(50) of each cell line followed by a decline back towards baseline. These findings indicate that masitinib mesylate causes dose-dependent HSA cell death in vitro and supports future clinical trials of masitinib for canine HSA.

Masitinib as a chemosensitizer of canine tumor cell lines: a proof of concept study.

Masitinib, a selective tyrosine kinase inhibitor, has previously been shown to enhance the antiproliferative effects of gemcitabine in human pancreatic cancer, demonstrating potential as a chemosensitizer. This exploratory study investigated the ability of masitinib to sensitize various canine cancer cell lines to doxorubicin, vinblastine, and gemcitabine. Masitinib strongly sensitized histiocytic sarcoma cells to vinblastine (>70-fold reduction in IC(50) at 5 µM masitinib), as well as osteosarcoma and mammary carcinoma cells to gemcitabine (>70-fold reduction at 5-10 µM). In addition, several cell lines were sensitized to doxorubicin (2-10-fold reduction at 10 µM). These data establish proof-of-concept that masitinib in combination with chemotherapeutic agents can generate synergistic growth inhibition in various canine cancers, possibly through chemosensitization. The findings justify further investigation into those combinations that may potentially yield therapeutic benefit.

Impact of telomerase status on canine osteosarcoma patients.

BACKGROUND: We demonstrated previously that canine osteosarcoma (OSA) cell lines and samples from clinical patients are predominantly telomerase positive. In contrast, the majority of OSA samples from human patients appear to be telomerase negative, maintaining telomere length by an alternative lengthening of telomeres (ALT) mechanism. The purpose of the current study was to examine the telomerase status of a large number of OSA samples from dogs and determine if telomerase status can serve as a prognostic factor. HYPOTHESIS: The majority of clinical canine OSA appendicular lesions will be telomerase positive, and telomerase positivity will negatively impact disease outcome. ANIMALS: Sixty-seven dogs with appendicular OSA presenting to the Colorado State University Animal Cancer Center for treatment. METHODS: The Telomeric Repeat Amplification Protocol was performed on tissue samples from primary canine appendicular OSA to determine the presence of telomerase activity. Telomere restriction fragment (TRF) analysis was utilized to determine telomere length and detect ALT. Outcome data were obtained in a retrospective manner and correlated with telomerase status. RESULTS: Seventy-three percent of canine OSA samples were telomerase positive. Telomerase status did not have an impact on disease-free interval or survival time. Nine of 10 telomerase-negative samples examined were consistent with an ALT phenotype, based on TRF analysis. CONCLUSIONS AND CLINICAL IMPORTANCE: These results are consistent with the hypothesis that the majority of canine OSA are telomerase positive, suggesting that telomerase may be a valuable target for canine OSA therapy. Additionally, telomerase status does not appear to be a prognostic factor in canine OSA.

Telomerase activity in canine osteosarcoma.

Appendicular osteosarcoma (OSA) is the most common primary bone tumour in dogs, and the prognosis with standard of care therapy of amputation and adjunctive chemotherapy is generally poor, with median survival times of 1 year. The ability of neoplastic cells to maintain their telomere length, by either telomerase activity or alternate methods, is an important step in tumour development and malignancy. The purpose of this study was to determine the presence of telomerase activity in canine OSA. To evaluate the frequency of alternative lengthening of telomeres in canine OSA, we have used the telomeric repeat amplification protocol in five canine cell lines and in six samples taken from clinical patients at the time of amputation. Our results reveal the presence of telomerase activity in 100% of canine OSA cell lines and 83% of clinical samples evaluated. This is in contrast to human OSA where 25-40% expression levels of telomerase are reported. Importantly, our results not only suggest that canine OSA may serve as a good model for aggressive telomerase-positive forms of human OSA but also that antitelomerase therapy strategies for treatment of canine OSA may be more successful than in the treatment of majority of human patients with OSA.

Nitrogen fixation. Endocrine disrupters and flavonoid signalling.

Nitrogen fixation is a symbiotic process initiated by chemical signals from legumes that are recognized by soil bacteria. Here we show that some endocrine-disrupting chemicals (EDCs), so called because of their effect on hormone-signalling pathways in animal cells, also interfere with the symbiotic signalling that leads to nitrogen fixation. Our results raise the possibility that these phytochemically activated pathways may have features in common with hormonal signalling in vertebrates, thereby extending the biological and ecological impact of EDCs.

Potential mechanisms of thyroid disruption in humans: interaction of organochlorine compounds with thyroid receptor, transthyretin, and thyroid-binding globulin.

Organochlorine compounds, particularly polychlorinated biphenyls (PCBs), alter serum thyroid hormone levels in humans. Hydroxylated organochlorines have relatively high affinities for the serum transport protein transthyretin, but the ability of these compounds to interact with the human thyroid receptor is unknown. Using a baculovirus expression system in insect cells (Sf9 cells), we produced recombinant human thyroid receptor ss (hTRss). In competitive binding experiments, the recombinant receptor had the expected relative affinity for thyroid hormones and their analogs. In competitive inhibition experiments with PCBs, hydroxylated PCBs (OH-PCBs), DDT and its metabolites, and several organochlorine herbicides, only the OH-PCBs competed for binding. The affinity of hTRss for OH-PCBs was 10,000-fold lower (Ki = 20-50 microM) than its affinity for thyroid hormone (3,3',5-triiodothyronine, T3; Ki = 10 nM). Because their relative affinity for the receptor was low, we tested the ability of OH-PCBs to interact with the serum transport proteins--transthyretin and thyroid-binding globulin (TBG). With the exception of one compound, the OH-PCBs had the same affinity (Ki = 10-80 nM) for transthyretin as thyroid hormone (thyroxine; T4). Only two of the OH-PCBs bound TBG (Ki = 3-7 microM), but with a 100-fold lower affinity than T4. Hydroxylated PCBs have relatively low affinities for the human thyroid receptor in vitro, but they have a thyroid hormonelike affinity for the serum transport protein transthyretin. Based on these results, OH-PCBs in vivo are more likely to compete for binding to serum transport proteins than for binding to the thyroid receptor.

Regulation by interleukin-1beta of formation of a line of delimiting astrocytes following prenatal trauma to the brain of the mouse.

The regulation of perinatal glia limitans (GL) reformation by interleukin-1beta (IL-1beta) following prenatal neural trauma in the mouse was studied in lesioned fetal mice by immunocytochemistry and computer-assisted image analysis for presence and distribution of astrocytes and IL-1beta immunoreactivity (ir). Astrocytes stained with anti-glial fibrillary acidic protein (GFAP) were observed as a line of delimiting astrocytes (LDA) near the lesion edge on Postnatal Day 0 (P0, 2 days postlesion). At P6, a new and complete GL composed of GFAP-positive astrocytes was continuous with that of adjacent undamaged tissue. The new GL was located in the same area at P6 as was the LDA at P0, suggesting that the LDA is the precursor structure to a reformed GL. Astrocytes comprising the new GL were positive for anti-IL-1beta. The IL-1 receptor antagonist (IL-1ra), administered acutely into the lesion, produced a significantly decreased optical density of IL-1beta-ir at the LDA at P0 compared to animals that received injections of vehicle, human recombinant IL-1beta, or a combination injection of IL-1ra + IL-1beta. Furthermore, although GFAP-stained cells appeared at the lesion site, an organized LDA was not visible at P0 in IL-1ra-treated animals. Vehicle-, IL-1beta-, and combination-injected animals showed a robust LDA at the lesion site at P0. These data suggest that upregulation of IL-1beta in astrocytes and interaction of IL-1beta with the neural IL-1 receptor are important for reconstruction of the GL following prenatal lesion in the murine brain.

The inhibition of estrogen receptor-mediated responses by chloro-S-triazine-derived compounds is dependent on estradiol concentration in yeast.

The chloro-S-triazine derived compounds atrazine, atrazine desisopropyl, cyanazine, and simazine are commonly used herbicides. These compounds do not have estrogenic activity in yeast expressing human estrogen receptor (hER) and an estrogen-sensitive reporter. In the presence of a concentration of estradiol (20 nM) that induced maximal reporter activity in yeast, the triazines did not inhibit reporter activity. However, the triazines decreased reporter activity in a dose dependent manner in the presence of a submaximal concentration of estradiol (0.5 nM). The estradiol-dependent activity of a mutant hER lacking the amino terminus was not inhibited by the triazines in yeast. Competition binding assays demonstrated that the triazines displaced radiolabeled estradiol from recombinant hER. These results suggest that the ability of the triazines to inhibit estrogen receptor-mediated responses in yeast occur through their interaction with hER and is dependent on the concentration of estradiol.