Antiviral effect of dietary germanium biotite supplementation in pigs experimentally infected with porcine reproductive and respiratory syndrome virus

Germanium biotite (GB) is an aluminosilicate mineral containing 36 ppm germanium. The present study was conducted to better understand the effects of GB on immune responses in a mouse model, and to demonstrate the clearance effects of this mineral against Porcine reproductive and respiratory syndrome virus (PRRSV) in experimentally infected pigs as an initial step towards the development of a feed supplement that would promote immune activity and help prevent diseases. In the mouse model, dietary supplementation with GB enhanced concanavalin A (ConA)-induced lymphocyte proliferation and increased the percentage of CD3+CD8+ T lymphocytes. In pigs experimentally infected with PRRSV, viral titers in lungs and lymphoid tissues from the GB-fed group were significantly decreased compared to those of the control group 12 days post-infection. Corresponding histopathological analyses demonstrated that GB-fed pigs displayed less severe pathological changes associated with PRRSV infection compared to the control group, indicating that GB promotes PRRSV clearance. These antiviral effects in pigs may be related to the ability of GB to increase CD3+CD8+ T lymphocyte production observed in the mice. Hence, this mineral may be an effective feed supplement for increasing immune activity and preventing disease.     

A case of chronic wasting disease in an elk imported to Korea from Canada

A seven-year-old male elk (Cervus elaphus nelsoni) was euthanized and necropsied after having a 3-week history of body weight loss, emaciation, excessive salivation, teeth grinding, fever, anorexia, and respiratory distress. The elk was imported into Korea from Canada on March 9, 1997. Gross pathologic findings were restricted to a diffuse fibrinous pneumonia. Microscopic lesions included mild neuronal vacuolation and spongiform change in the neuropil of selected brain stem nuclei and generalized astrocytosis. Immunohistochemistry for protease-resistant prion protein (PrP(res)) was positive in all brain sections but more pronounced in the section of the obex of the medulla. And the PrP(res) was also detected by western immunoblotting in the brain and spinal cord. All the remaining elk and deer that had been in contact with this elk were destroyed and negative for chronic wasting disease (CWD). To our knowledge, this is the first case of CWD occurring outside of the U.S.A. and Canada.     

Effects of chemical treatments on pH and bacterial population in poultry litter: a laboratory experiment

1. The goal of this study was to evaluate the effects of three chemical treatments on pH and bacterial populations (total aerobic bacteria and gram-negative bacteria) in poultry litter under laboratory conditions. 2. Litter obtained from poultry houses was treated with three chemical treatments (alum, AlCl(3) and FeSO(4)) at the same concentration (8 g/100 g litter), while untreated litter served as a control. The study was conducted for 3 weeks. 3. All of the chemical treatments reduced total aerobic bacteria (22 to 87% of the untreated control) and gram-negative bacteria (63 to 99% of the untreated controls) populations and lowered litter pH values (5.95 to 6.64). However, a significant difference in gram-negative bacteria did not exist among chemical treatments at 0, 1 and 2 weeks. 4. These results suggest that the reduction in total aerobic bacteria and gram-negative bacteria populations is highly related to a decrease in litter pH, and acidifying treatment (alum, AlCl(3) and FeSO(4)) of poultry litter may serve as a means to help the reduction in pathogen populations and to improve economical benefits under commercial production conditions.     

Genetic analysis of ORF5 of recent Korean porcine reproductive and respiratory syndrome viruses (PRRSVs) in viremic sera collected from MLV-vaccinating or non-vaccinating farms

The 23 open reading frame (ORF) 5 sequences of Korean type II porcine reproductive and respiratory syndrome virus (PRRSV) were collected from viremic sera from the (modified live vaccine) MLV-vaccinating and non-vaccinating farms from 2007 to 2008. The samples were phylogenetically analyzed with previous ORF5 sequences, including type I Korean PRRSV, and previously reported or collected sequences from 1997 to 2008. A MN184-like subgroup of type II Korean PRRSV was newly identified in the viremic sera collected from 2007 to 2008. And of the type I PRRSVs, one subgroup had 87.2~88.9% similarity with the Lelystad virus, showing a close relationship with the 27~2003 strain of Spain. The maximum parsimony tree of type II PRRSV from 1997 to 2008 showed that they had evolved to four lineages, subgroups 1, 2, 3 and 4. Most of the recently collected type II PRRSVs belonged to subgroup 4 (48%). The region of three B-cell epitopes and two T-cell epitopes of ORF5 amino acids sequences was considerably different from the MLV in subgroups 3 and 4. In conclusion, the existence of type I PRRSV, which was genetically different from Lelystad virus (Prototype of type I PRRSV), and heterologous type II PRRSVs of viremic pigs detected even in the MLV-vaccinating farms indicated the need for new vaccine approaches for the control of PRRSV in Korea.     

Gingival overgrowth in dogs associated with clinically relevant cyclosporine blood levels: observations in a canine renal transplantation model

Objective— To investigate the development of gingival hyperplasia in dogs after renal transplantation and administration of microemulsified cyclosporine A (MCsA).
Study Design— Experimental study.
Animals— Healthy adult mongrel dogs (n=5).
Methods— As part of study on renal transplantation, dogs administered MCsA (20 mg/kg/day), azathioprine, and prednisolone to prevent graft rejection were monitored for development of gingival changes. Prednisolone was discontinued after 3 months. MCsA dose was adjusted to maintain whole blood trough concentration of 400–700 ng/mL. Gingival change was evaluated by weekly examination and photodocumentation, and gingival biopsy for histopathology was performed at 28 weeks.
Results— One dog was lost because of acute graft rejection. Gingival hyperplasia developed in 3 of 4 dogs. The earliest gingival changes occurred in the interdental papillae at 20 weeks after transplantation. On histopathology, the underlying connective tissue was thickened and contained increase numbers of fibroblasts and inflammatory infiltrates.
Conclusions— Long-term immunosuppression with an MCsA-based treatment likely induces substantial gingival hyperplasia when therapeutic, immunosuppressive blood levels of MCsA were maintained for 32 weeks.
Clinical Relevance— MCsA is used for immune-mediated diseases and preventing rejection after transplant in dogs. MCsA blood levels, and gingival hyperplasia should be monitored by routine examination of the interdental papilla in dogs administered MCsA for long periods.     

Evaluation of canine gastric motility with ultrasonography

For the evaluation of canine gastric motility with ultrasonography, contraction number of pyloric antrum and gastric emptying time (GET) by area and volume method developed by Bolondi et al.'s method were studied in 14 dogs. All experimental dogs were administered with saline and soup solution (10 ml/kg, B.W.). The mean values of contraction number of pyloric antrum in saline and soup group were 4.19 +/- 1.30/min and 4.82 +/- 0.65/min before feeding, and overall mean values were 4.66 +/- 1.37/min and 5.13 +/- 1.71/min, respectively. The mean values of the GET by area and volume method were 36.73 +/- 11.27, 40.00 +/- 8.87 min in saline group and 61.35 +/- 17.58, 59.11 +/- 14.46 min in soup group. In the GET in saline and soup groups, there was no significant difference between the area and volume method (p>0.05). Therefore, Bolondi et al.'s method by ultrasound can be used to evaluate the antropyloric motility and gastric emptying time with area and volume methods. The area method is easier to determine the GET than the volume method, but the latter is more accurate.