Animal models for human metapneumovirus (HMPV) infections

Since its detection in 2001 the human Metapneumovirus (HMPV), a member of the Paramyxoviridae family, was observed to be a serious pathogen in human respiratory infections during childhood. Meanwhile, several animal models have been established to study the virus-host interactions and pathogenic effects. Mainly, small laboratory animals like mice and cotton rats have been used, although the usage of these two species for HMPV research is controversially discussed and contradictious results were obtained by different groups. Further trials with ferrets, hamsters and non human primates were performed revealing different success in their individual usage. In this review we present the different animal models, summarize their advantages and disadvantages, and discuss the controversial results from different studies.     

The analgesic and sedative effects of GV20 pharmacopuncture with low-dose hydromorphone in healthy dogs undergoing ovariohysterectomy

This study evaluates the analgesic efficacy of low-dose hydromorphone administered via pharmacopuncture at Governing Vessel 20 (GV20) for postoperative pain management following canine ovariohysterectomy. Fifty clinically healthy female dogs undergoing ovariohysterectomy were allocated to receive hydromorphone [0.1 mg/kg body weight (BW)] intramuscularly (IM, n = 25) or hydromorphone (0.01 mg/kg BW) pharmacopuncture at GV20 (GV, n = 25) following extubation. This was a prospective, blinded, randomized clinical trial. Pain and sedation scores were evaluated using the Glasgow Composite Measure Pain Scale Short Form (CMPS-SF) at 1, 2, 3, 4, and 12 hours following study treatment. Time of treatment failure (CMPS-SF ≥ 6/24) was recorded and analyzed using Kaplan-Meier survival analysis. Patient demographics and duration of surgery and anesthesia were analyzed using the appropriate unpaired Student’s t-test. The Glasgow CMPS-SF and sedation score were analyzed using a repeated measures 2-way analysis of variance (ANOVA) followed by Bonferroni post-test where appropriate. Significance was set a P < 0.05. There were no significant differences in patient demographics, anesthesia and surgery duration, and study treatment failure. The Glasgow CMPS-SF scores were significantly higher for IM compared with GV [2 (0 to 8) versus 1 (0 to 6), respectively; P = 0.044] at 4 hours. Sedation scores were significantly higher for IM compared with GV at 2 [2 (1 to 3) and 1 (1 to 3), respectively; P = 0.0004] and 4 [1 (1 to 3) and 1 (1 to 2), respectively; P = 0.03] hours. Pharmacopuncture with low-dose hydromorphone provided adequate postoperative analgesia in dogs undergoing ovariohysterectomy with reduced sedative effects. Pharmacopuncture is a good alternative in dogs when reduced dosing of opioids is recommended.     

Plasma glucose-insulin relationship in chicken lines selected for high or low fasting glycaemia

1. Selected Fat or Lean chickens differ in their plasma glucose insulin relationship: in the fed or fasted state, Fat chickens have a lower glycaemia associated with normal or higher insulinaemia, depending upon the difference in glycaemia. 2. Conversely, chickens selected for low fasting glycaemia (LG) are fattier than their counterparts selected for high fasting glycaemia (HG), although the divergence in fat content is lower than in the Fat-Lean model. 3. The plasma glucose insulin relationship has been investigated in males of the HG and LG lines in the F4 and F5 generations. 4. A difference in glycaemia is suggested during embryonic development and was present at hatching and later on in the fasted or the fed state; insulinaemia did not differ. 5. During refeeding after an overnight fast, glycaemia differed between lines (except at intermediate times); cumulative food intake and insulinaemia were similar. 6. During a glucose tolerance test, glucose disposal rate and insulinaemia were rather similar. 7. Exogenous insulin exerted a very similar hypoglycaemic effect in both lines. 8. Other variables (body temperature, plasma concentrations of potassium and alpha NH2-non protein nitrogen) did not differ between HG and LG chickens. 9. In conclusion, HG and LG chickens do not exhibit any differences in glucose disposal rate, insulinaemia (in various nutritional conditions) or sensitivity to exogenous insulin, which contrasts with Fat or Lean chickens and may explain why HG and LG chickens have diverged to a lesser extent in fat content.     

MAGNETIC RESONANCE IMAGING APPEARANCE OF SUSPECTED ISCHEMIC MYELOPATHY IN DOGS

Ischemia and infarction of the spinal cord is a known cause of acute spinal injury in dogs. Currently, the diagnosis of spinal cord infarction in small animals is based on history, clinical signs, and the exclusion of other differentials with radiography and myelography. It is a diagnosis only confirmed through necropsy examination of the spinal cord. The aim of this paper is to describe the Magnetic resonance imaging (MRI) findings of the spinal cord of dogs with suspected spinal cord infarcts to utilize this technology for antemortem support of this diagnosis. This retrospective study evaluated the spinal MR examinations of 11 dogs with acute onset of asymmetric nonpainful myelopathies. All patients except one (imaged at 2 months) were imaged within 1 week of clinical signs and managed conservatively with minimal medical and no surgical intervention. They were followed clinically for a minimum of 4 months after discharge. MR findings in all dogs were characterized by focal, intramedullary, hyperintense lesions on T2-weighted images with variable contrast enhancement similar to what is reported in humans. Though it could not be used to diagnose spinal cord infarction definitively, MRI was useful in excluding extramedullary spinal lesions and supporting intramedullary infarction as a cause of the acute neurologic signs. Together with the history and clinical examination findings, MRI is supportive of a diagnosis of spinal cord infarction.     

Plasma endotoxin concentration in horses: a methods study

Background: Accurate determination of plasma endotoxin concentration is critical for ex vivo and in vitro cellular and molecular studies of endotoxemia in horses. However, reports are conflicting with respect to anticoagulant, handling, and sample preparation.

Objective:

Objective: The purpose of this study was to determine the effect of blood sample fraction and handling time on measurement of endotoxin concentration in horses.

Methods:

Methods: Whole blood, anticoagulated with 3.8% (0.12 M) sodium citrate (9:1), was collected from 5 healthy horses. Whole blood (WB), platelet-rich plasma (PRP), and platelet-poor plasma (PPP) were spiked with endotoxin (2 EU/mL). Endotoxin-spiked WB samples were centrifuged immediately to generate PRP for measurement. Endotoxin concentration was subsequently measured by Limulus amebocyte assay at 0, 15, 30, 45, and 60 minutes. Assays were performed in triplicate and results were analyzed using Student's t -test, with significance set at P < .05.

Results:

Results: Mean endotoxin concentrations in 2 EU/mL-spiked WB were significantly different from those in PPP at all time points tested. Recovery of endotoxin in PRP generated from WB was significantly diminished after just 15 minutes.

Conclusion:

Conclusion: PRP generated from WB is significantly more reliable than PPP in determining endotoxin concentration ex vivo. Measurement of endotoxin in PRP generated from WB was significantly diminished after 15 min, identifying a time frame within which to process blood samples for endotoxin analysis.     

Immunopathogenic behaviors of canine transmissible venereal tumor in dogs following an immunotherapy using dendritic/tumor cell hybrid

Canine transmissible venereal tumor (CTVT) is a naturally occurring tumor that can be transmitted between dogs via live tumor cell inoculation. It is also a spontaneous self-regression tumor and its behavior is closely related to host immune responses. Since CTVT had been widely used for tumor models in canine cancers, whether this self-regression may overtake the immunity elicited from an exogenous tumor vaccine remains unclear and certainly worthwhile to be investigated. In this study, we used DCs/tumor hybrids as a tumor vaccine to evaluate the CTVT model. We prepared mature allogeneic dendritic cells from bone marrow and then assessed their phenotype (CD80, CD83, CD86, CD1a, CD11c, CD40 and MHC II), antigen uptake and presenting abilities. Fused dendritic cell/CTVT hybrids were then used as a vaccine, administered three times at two-week intervals via subcutaneous injection near the bilateral auxiliary and inguinal lymph nodes. In comparison with unvaccinated dogs (spontaneous regressed group), within a period of 2.5 months, the vaccinations substantially inhibited tumor progression (p<0.05) and accelerated the rate of regression by a mechanism involving amplification of the host tumor-specific adaptive immune responses and NK cytotoxicity (p<0.001). Pathologic examination revealed early massive lymphocyte infiltration resulting in final tumor necrosis. In addition, there are not any detectable effects on routine physical, body temperature or blood chemistry examinations. In conclusion, our data furnishes a reference value showing that CTVT is a model of potential use for the study of immunity elicited by vaccines against tumors, and also enable early-phase evaluation of the dendritic cell/tumor vaccine in terms of raising host immunity.     

Effect of exogenous corticosterone in genetically fat and lean chickens

1. The effects of daily injections of corticosterone (1 or 5 mg/bird) on growth, fat deposition, liver lipid and plasma concentrations of uric acid, glucose, insulin and growth hormone were studied using genetically selected lines of fat (FL) and lean (LL) chickens. 2. Both doses of corticosterone depressed body weight gain and increased the liver lipid and the abdominal fat to the same extent in both lines. 3. In both lines, corticosterone caused a dose-dependent increase in the plasma concentrations of uric acid, glucose and insulin in the fasted and refed states. 4. In untreated birds, plasma concentrations of growth hormone (GH) were slightly higher in FL than in LL chickens and slightly decreased during refeeding. The response was not modified by injection of 1 mg corticosterone. Injections of 5 mg decreased plasma GH in both lines in the fasting state and in LL chickens during refeeding. In contrast, the same dose increased GH in FL chickens during refeeding. This contradiction remains unexplained. 5. The results suggest that corticosterone sensitivity is not involved in difference of fattening between FL and LL chickens.