Vaccination of ferrets with a recombinant G glycoprotein subunit vaccine provides protection against Nipah virus disease for over 12 months.

BACKGROUND: Nipah virus (NiV) is a zoonotic virus belonging to the henipavirus genus in the family Paramyxoviridae. Since NiV was first identified in 1999, outbreaks have continued to occur in humans in Bangladesh and India on an almost annual basis with case fatality rates reported between 40% and 100%. METHODS: Ferrets were vaccinated with 4, 20 or 100 µg HeVsG formulated with the human use approved adjuvant, CpG, in a prime-boost regime. One half of the ferrets were exposed to NiV at 20 days post boost vaccination and the other at 434 days post vaccination. The presence of virus or viral genome was assessed in ferret fluids and tissues using real-time PCR, virus isolation, histopathology, and immunohistochemistry; serology was also carried out. Non-immunised ferrets were also exposed to virus to confirm the pathogenicity of the inoculum. RESULTS: Ferrets exposed to Nipah virus 20 days post vaccination remained clinically healthy. Virus or viral genome was not detected in any tissues or fluids of the vaccinated ferrets; lesions and antigen were not identified on immunohistological examination of tissues; and there was no increase in antibody titre during the observation period, consistent with failure of virus replication. Of the ferrets challenged 434 days post vaccination, all five remained well throughout the study period; viral genome - but not virus - was recovered from nasal secretions of one ferret given 20 µg HeVsG and bronchial lymph nodes of the other. There was no increase in antibody titre during the observation period, consistent with lack of stimulation of a humoral memory response. CONCLUSIONS: We have previously shown that ferrets vaccinated with 4, 20 or 100 µg HeVsG formulated with CpG adjuvant, which is currently in several human clinical trials, were protected from HeV disease. Here we show, under similar conditions of use, that the vaccine also provides protection against NiV-induced disease. Such protection persists for at least 12 months post-vaccination, with data supporting only localised and self-limiting virus replication in 2 of 5 animals. These results augur well for acceptability of the vaccine to industry.

Antitumor activities and on-target toxicities mediated by a TRAIL receptor agonist following cotreatment with panobinostat.

The recent development of novel targeted anticancer therapeutics such as histone deacetylase inhibitors (HDACi) and activators of the TRAIL pathway provide opportunities for the introduction of new treatment regimens in oncology. HDACi and recombinant TRAIL or agonistic anti-TRAIL receptor antibodies have been shown to induce synergistic tumor cell apoptosis and some therapeutic activity in vivo. Herein, we have used syngeneic preclinical models of human solid cancers to demonstrate that the HDACi panobinostat can sensitize tumor cells to apoptosis mediated by the anti-mouse TRAIL receptor antibody MD5-1. We demonstrate that the combination of panobinostat and MD5-1 can eradicate tumors grown subcutaneously and orthotopically in immunocompetent mice, while single agent treatment has minimal effect. However, escalation of the dose of panobinostat to enhance antitumor activity resulted in on-target MD5-1-mediated gastrointestinal toxicities that were fatal to the treated mice. Studies performed in mice with knockout of the TRAIL receptor showed that these mice could tolerate doses of the panobinostat/MD5-1 combination that were lethal in wild type mice resulting in superior tumor clearance. Given that clinical studies using HDACi and activators of the TRAIL pathway have been initiated, our preclinical data highlight the potential toxicities that could limit the use of such a treatment regimen. Our studies also demonstrate the power of using syngeneic in vivo tumor models as physiologically relevant preclinical systems to test the antitumor effects and identify potential side effects of novel anticancer regimens.

Notch1 functions as a tumor suppressor in a model of K-ras-induced pancreatic ductal adenocarcinoma.

K-ras is the most commonly mutated oncogene in pancreatic cancer and its activation in murine models is sufficient to recapitulate the spectrum of lesions seen in human pancreatic ductal adenocarcinoma (PDAC). Recent studies suggest that Notch receptor signaling becomes reactivated in a subset of PDACs, leading to the hypothesis that Notch1 functions as an oncogene in this setting. To determine whether Notch1 is required for K-ras-induced tumorigenesis, we used a mouse model in which an oncogenic allele of K-ras is activated and Notch1 is deleted simultaneously in the pancreas. Unexpectedly, the loss of Notch1 in this model resulted in increased tumor incidence and progression, implying that Notch1 can function as a tumor suppressor gene in PDAC.

Evaluation of risk factors for morbidity and mortality after pylorectomy and gastroduodenostomy in dogs.

OBJECTIVES: To (1) identify and describe the type and frequency of postoperative complications after pylorectomy and gastroduodenostomy in dogs and (2) identify preoperative and intraoperative risk factors, including the presence of neoplasia, prognostic for patient mortality after surgery. STUDY DESIGN: Case series. ANIMALS: Dogs (n=24) treated by pylorectomy and gastroduodenostomy. METHODS: Medical records (2000-2007) for 2 teaching hospitals of dogs treated that had pylorectomy and gastroduodenostomy were reviewed. Pre-, intra-, and postoperative data were obtained from the medical record. RESULTS: Of the 24 dogs, 75% survived 14 days, but 10 (41%) died by 3 months. Overall median survival time (MST) was 578 days. On log-rank univariate analysis, preoperative weight loss (P=.001) and malignant neoplasia (P=.01) were associated with decreased survival time. Dogs with malignant neoplasia had a MST of 33 days. Common postoperative morbidity included hypoalbuminemia (62.5%) and anemia (58.3%). CONCLUSIONS: Pylorectomy with gastroduodenostomy has a good short-term outcome but long-term survival time is poor in dogs with malignant neoplasia. CLINICAL RELEVANCE: Overall, most dogs treated with pylorectomy and gastroduodenostomy survived the postoperative period; however, preoperative weight loss and malignant neoplasia were associated with decreased survival time. Because dogs with malignant neoplasia have markedly shortened survival times, pertinent preoperative, diagnostics steps should be exhausted to identify underlying neoplasia.

Contrast harmonic ultrasonography of splenic masses and associated liver nodules in dogs.

OBJECTIVE: To determine whether contrast harmonic ultrasonography (CHUS) can be used in dogs to distinguish splenic hemangiosarcoma from hematoma and to accurately detect and characterize liver nodules. DESIGN: Cross-sectional study. ANIMALS: 20 dogs with a splenic mass. PROCEDURES: Routine abdominal ultrasonography was followed by CHUS of hepatic and splenic lesions. Qualitative evaluation included location, enhancement pattern, and vascularity of lesions. Quantitative evaluation included peak mean pixel intensity, interval to peak intensity, area under the curve (spleen), and liver-to-lesion intensity ratio (liver). Histologic findings were compared with CHUS lesion characteristics. RESULTS: Histologic evaluation of the spleen was performed in 19 dogs, resulting in diagnoses of hemangiosarcoma (n=11), hematoma (7), and undifferentiated sarcoma (1). Benign and malignant processes in the spleen were indistinguishable via CHUS. Histologic evaluation of the liver was performed in 18 dogs, resulting in a diagnosis of hemangiosarcoma in 5 dogs. None of the dogs with splenic hematomas had evidence of hepatic lesions by means of conventional or contrast ultrasonography, and none had histologic evidence of liver metastases. In 3 of 18 dogs, isoenhancing liver nodules were detected and all were histologically benign. Five dogs had liver nodules that remained hypoechoic after contrast agent was injected; all had histologic evidence of metastatic hemangiosarcoma. Results of CHUS were used to characterize hepatic metastases with 100% sensitivity and specificity. CONCLUSIONS AND CLINICAL RELEVANCE: Contrast harmonic ultrasonography was a noninvasive and accurate means of differentiating metastatic versus benign hepatic disease in dogs with splenic hemangiosarcoma but was not useful in distinguishing splenic hemangiosarcoma from hematoma.

Physiologic alterations in the murine model after nasal fungal antigenic exposure.

OBJECTIVE: To determine whether a recently developed murine model of fungus-induced sinonasal inflammation demonstrated alterations in ciliary activity and expression of inflammatory cytokines. STUDY DESIGN: A prospective randomized controlled study of rhinosinusitis after fungal antigenic sensitization was performed with intraperitoneal aspergillus antigen injection followed by intranasal antigen challenge for 4 weeks. Saline solution was used in a parallel fashion for control animals. SUBJECTS AND METHODS: Six mice were used to validate the model. Additional 15 mice were used for ciliary beat frequency (CBF) analysis and cytokine expression with multiplex technology. Mean values for degree of inflammation, secretory hyperplasia, CBF, and cytokine expression were compared. RESULTS: Histologic analyses demonstrated dense chronic inflammation in aspergillus-challenged animals versus sparse inflammatory cells in controls. Significant differences in mean of aspergillus-challenged versus control animals were observed in degree of inflammation (P < 0.01), secretory hyperplasia (P < 0.01), CBF (P < 0.00002), IL-1alpha (P < 0.0002), IL-1beta (P < 0.0003), IL-4 (P < 0.02), TNF-alpha (P < 0.02), and RANTES (P < 0.01). CONCLUSION: Alteration in baseline CBF accompanied by increased expression of specific inflammatory cytokines was observed in aspergillus-challenged mice.

Evaluation of rapid staining techniques for cytologic diagnosis of intracranial lesions.

OBJECTIVE: To evaluate 4 rapid supravital stains and 3 preparation techniques for use in the intraoperative diagnosis of intracranial lesions. ANIMALS: 10 dogs and 1 cat euthanatized for intracranial lesions. PROCEDURE: Specimens were taken from lesions and slides prepared, using 3 techniques: touch impression, medium-pressure impression, or smear preparation. Preparations were then stained with 4 stains: modified Wright stain, May-Grünwald-Giemsa, toluidine blue, and zynostain and examined in a blinded randomized fashion. Cytologic diagnosis was compared with histopathologic diagnosis and classified on the basis of identification of the pathologic process and specific diagnosis into the following categories: complete correlation, partial correlation, or no correlation. RESULTS: An overall diagnostic accuracy of 81% (107/132) was achieved on the basis of a combination of partial and complete correlation. Of the stains examined, modified Wright stain appeared to be most accurate, with complete correlation in 17 of 33 (52%) specimens and partial correlation in 12 of 33 (36%) specimens. Of the preparation methods, touch preparation and smear preparation provided the most accurate results, with an overall diagnostic accuracy of 82% (36/44) for both methods. However, smear preparations appeared to be of greater diagnostic value, with fewer nondiagnostic specimens, compared with touch preparations. CONCLUSIONS AND CLINICAL RELEVANCE: Cytologic preparations provide a useful diagnostic tool for the intraoperative diagnosis of intracranial lesions. All stains examined yielded promising results, the most accurate of which appeared to be the modified Wright stain. The smear preparation appeared to be the preparation method of greatest diagnostic value.