Recombinant human hepatitis B vaccine initiating alopecia areata: testing the hypothesis using the C3H/HeJ mouse model

Untoward effects of human vaccines suggest that recombinant hepatitis B vaccine may induce alopecia areata (AA) in some patients. Similar untoward immunological effects may also account for AA-like diseases in domestic species. In this study, the C3H/HeJ spontaneous adult onset AA mouse model was used to test the role, if any, of recombinant hepatitis B vaccine on the initiation or activation of AA. Initial experiments demonstrated no effect on induction of AA in young adult female C3H/HeJ mice ( P  = 0.5689). By contrast, older females, those at the age when AA first begins to appear in this strain, had a significant increase ( P  = 0.0264) in the time of onset of AA, suggesting that the vaccine may initiate disease in mice predisposed to AA. However, larger vaccine trials, which included diphtheria and tetanus toxoids as additional controls, did not support these initial result findings and suggest that AA associated with vaccination may be within the normal background levels of the given population.     

Feline head and neck squamous cell carcinoma: a natural model for the human disease and development of a mouse model

Head and neck squamous cell carcinoma (H/N SCC) is a devastating disease in humans and cats, and shares similar features between the two species. The large population of pet cats inthe United States, along with the high incidence of oral SCC in the cat, makes the cat an attractive candidate as a natural model for the human disease. There are similarities in pathology, progression, outcome, resistance to treatment, possible aetiologies and p53 expression, and we discuss the benefits of the cat as a natural model. We describe the development of a nude mouse xenograft model of feline oral SCC using the SCCF1 cell line transfected with a luciferase expression construct. In vivo tumour growth and metastasis were measured using serial bioluminescent imaging, and tumours grew best in the subcutis. The cat and nude mouse models will be useful to investigate the pathogenesis and the molecular basis of H/N SCC, and for preclinical drug screening.     

Pharmacokinetics of theophylline in swine: a potential model for human drug bioavailability studies

The pharmacokinetics of theophylline in swine were investigated following die oral and intravascular administration of single doses of theophylline free base. The mean half-life of theophylline following intravascular administration was 11.0 h, and the apparent specific volume of distribution was 0.61 liter/kg. Following oral administration, theophylline in solution was absorbed quite rapidly with a bioavailability of 79%. The similarity of the pharmacokinetics of theophylline in swine and humans suggests that swine may provide a useful model for the study of the bioequivalency of theophylline dosage forms intended for human use. The pharmacokinetic characteristics of theophylline also favor its consideration for usage as a therapeutic agent in swine.     

Comparative studies on the binding specificities of pertussis toxin and different lectins to human erythrocytes

The binding specificity of pertussis toxin (PT) was compared with lectins with well-defined specificities by hemagglutination, hemagglutination inhibition and competitive binding assays. Neuraminidase-treated human erythrocytes were much less weakly agglutinated by PT than untreated ones. Hemagglutination of untreated human type A erythrocytes by PT was inhibited by fetuin, haptoglobulin and hog A + H. Mono- and disaccharides, and N-acetylneuraminic acid alone were ineffective at the highest concentrations used. On the other hand, hemagglutination by Ricinus communis agglutinin (RCA-1) was effectively inhibited by these substances. Similar results were also obtained in competitive binding assays with 123I-labeled PT and untreated type A erythrocytes. The binding of 125I-labeled PT to type A erythrocytes was not effectively inhibited by any of lectins with well-defined specificities. These results suggest that the combining site of PT may be specific for terminal sialic acid and/or sialic acid-linked carbohydrate portion(s) which can not be recognized by lectins reported previously.     

Detection of CC17 Enterococcus faecium in dogs and a comparison with human isolates

Enterococcus faecium strains of clonal complex (CC) 17 were isolated from domestic dogs. The strains were more prevalent in infectious isolates than in colonized isolates, suggesting that strains of the CC17 lineage may have an advantage in causing infections in dogs. The pulsed field gel electrophoresis patterns of some dog and human isolates were over 90% similar. However, antimicrobial resistance patterns and virulence factors were not identical, which might reflect different use of antimicrobials in veterinary medicine or in host specificity.     

Optimization of the use of C57BL/6 mice as a laboratory animal model for Neospora caninum vaccine studies

The development and testing of vaccines for Neospora caninum in mice require challenge studies to demonstrate a reduction in clinical signs or prevention of vertical transmission of the parasite after vaccination. Genetic susceptibility to N. caninum varies with the strain of mice. In this study, C57BL/6 mice were evaluated as a model for Neospora vaccine studies. A lethal challenge model was developed and the LD(50) was determined to be 1.5 x 10(7)N. caninum tachyzoites/mouse, delivered intraperitoneally. Brain lesions encountered in sections from sub-lethally challenged mice were scored on the basis of severity and total number of lesions to develop a histopathological scoring system for vaccine efficacy. A vertical transmission model for N. caninum vaccine studies was developed by studying mice that were infected either 2 weeks prior to mating or between days 12 and 14 of pregnancy. It was found that infection prior to mating reduced the average number of pups per litter. DNA extracted from fetal tissue was examined by a N. caninum specific polymerase chain reaction (PCR). The rate of vertical transmission was 0, 100 and 90.5% for the uninfected controls, mice infected during pregnancy and mice infected before mating, respectively. This study demonstrates that the C57BL/6 strain of mice is a good model for N. caninum vaccine studies because it is possible to establish a clear-cut lethal challenge model in C57BL/6 mice and they transmit the disease to their offspring efficiently.     

Evaluation of host and bacterial gene modulation during Lawsonia intracellularis infection in immunocompetent C57BL/6 mouse model

BackgroundProliferative enteritis caused by Lawsonia intracellularis undermines the economic stability of the swine industry worldwide. The development of cost-effective animal models to study the pathophysiology of the disease will help develop strategies to counter this bacterium.ObjectivesThis study focused on establishing a model of gastrointestinal (GI) infection of L. intracellularis in C57BL/6 mice to evaluate the disease progression and lesions of proliferative enteropathy (PE) in murine GI tissue.MethodsWe assessed the murine mucosal and cell-mediated immune responses generated in response to inoculation with L. intracellularis.ResultsThe mice developed characteristic lesions of the disease and shed L. intracellularis in the feces following oral inoculation with 5 × l0⁷ bacteria. An increase in L. intracellularis 16s rRNA and groEL copies in the intestine of infected mice indicated intestinal dissemination of the bacteria. The C57BL/6 mice appeared capable of modulating humoral and cell-mediated immune responses to L. intracellularis infection. Notably, the expression of genes for the vitamin B12 receptor and for secreted and membrane-bound mucins were downregulated in L. intracellularis -infected mice. Furthermore, L. intracellularis colonization of the mouse intestine was confirmed by the immunohistochemistry and western blot analyses.ConclusionsThis is the first study demonstrating the contributions of bacterial chaperonin and host nutrient genes to PE using an immunocompetent mouse model. This mouse infection model may serve as a platform from which to study L. intracellularis infection and develop potential vaccination and therapeutic strategies to treat PE.     

Cultivation of Ehrlichia canis in a continuous BALB/C mouse macrophage cell culture line.

This report describes the successful adaptation of the Israeli isolate of Ehrlichia canis on a continuous mouse macrophage cell line (J774.A1). Successful infection of the J774.AI cells was first judged by the direct immunofluorescence antibody test using an anti-E. canis-IgG:FITC conjugate. A particular property of infected J774.A1 cells was the ability to reestablish after harvesting of the monolayer by scaping. Infected cells were used as antigen for immunofluorescence antibody tests (IFA), and the results compared well with those of DH82 cells. It was concluded that the J774.A1 continuous cell line could serve as an alternate propagation cell line for E. canis organisms.     

The effects of furosemide and pentoxifylline on the flow properties of equine erythrocytes:In vitro studies

The effects of various concentrations of furosemide and pentoxifylline on equine RBCin vitro were evaluated to facilitate better understanding of the potential effects of these drugs on blood flow properties. Furosemide induced increased mean cell volume (MCV), increased RBC potassium concentration, increased whole blood viscosity, and decreased the RBC filtrability. These data indicate that furosemide may block the RBC membrane transport pathways resulting in potassium and water retention. The increase in size and the resultant decrease in the surface-area-to-volume ratio may have caused the impaired RBC filtrability and increased blood viscosity. Pentoxifylline improved RBC filtrability without changing the RBC size or the potassium or chloride concentrations, suggesting that pentoxifylline may increase the deformability of the RBC membrane. The study indicated that pentoxifylline has potential therapeutic applications for improving microvascular blood flow but that furosemide may have adverse effects on blood flow.Abbreviations cP centipoise - EIPH exercise-induced pulmonary haemorrhage - MCV mean cell volume - Na-K-2Cl sodium potassium 2-chloride - PCV packed cell volume - RBC red blood cell     

Mechanisms of resistance and susceptibility to experimental visceral leishmaniosis: BALB/c mouse versus syrian hamster model

ABSTRACT: Several animal models have been established to study visceral leishmaniosis (VL), a worldwide vector-borne disease affecting humans and domestic animals that constitutes a serious public health problem. BALB/c mice and Syrian hamsters are the most widely used experimental models. In this paper, we summarize the advantages and disadvantages of these two experimental models and discuss the results obtained using these models in different studies of VL. Studies using the BALB/c mouse model have underscored differences between the liver and spleen in the course of VL, indicating that pathological evaluation of the visceral organs is essential for understanding the immune mechanisms induced by Leishmania infantum infection. The main goal of this review is to collate the relevant literature on Leishmania pathogenesis into a sequence of events, providing a schematic view of the main components of adaptive and innate immunity in the liver and spleen after experimental infection with L. infantum or L. donovani. This review also presents several viewpoints and reflections about some controversial aspects of Leishmania research, including the choice of experimental model, route of administration, inoculum size and the relevance of pathology (intimately linked to parasite persistence): a thorough understanding of which is essential for future VL research and the successful development of efficient control strategies for Leishmania spp.     

骆驼、牛、羊、人乳中维生素C含量测定与比较

糖尿病（DM）是由环境和遗传因素联合作用而致的一种慢性代谢性疾病,以高血糖状态为特征,多并发症引起高死亡率和致残率,严重威胁人类健康。近年来全球DM患病率呈逐年上升趋势,发达国家和地区的患病率高达2％-5％。     

A comparison of the pathogenicity of two strains of hog cholera virus: 1. Clinical and pathological studies

The virulence of a strain of hog cholera virus isolated during an outbreak of mild disease in pigs in New South Wales in 1960/61 (the NSW strain) was compared over 11 days with that of a virulent strain by inoculating 8 pigs with each virus and comparing the ensuing clinical signs and pathology. Both viruses caused persistent pyrexia and leukopenia, the NSW strain 4 to 5 days and the virulent strain 3 days, after inoculation. Few other clinical signs were observed in the pigs inoculated with the NSW strain. In contrast, all pigs inoculated with the virulent strain became progressively depressed and incoordinated, and were killed between days 6 and 9. Bronchopneumonia and swollen, reddened lymph nodes were observed in pigs inoculated with both viruses. Few other gross lesions were observed with the NSW strain, but some pigs receiving the virulent strain had pustules in the tonsil and the anterior oesophagus, petechial haemorrhages in the kidney, and small infarcts at the margins of the spleen. There were marked differences in the histopathology, both in the variety of organs affected and the severity of lesions in individual organs. Suppurative bronchopneumonia occurred in both groups. Other changes in the pigs affected with the NSW strain were colitis, mild cerebral vasculitis, necrosis, haemorrhage and neutrophil infiltration in some lymph nodes and spleens. In pigs infected with virulent virus the cerebral vasculitis was so severe that there was necrosis of cells within the vessel walls.(ABSTRACT TRUNCATED AT 250 WORDS)     

Analysis of mouse, rat, dog, marmoset, and human serum proteins by capillary electrophoresis: comparison with agarose gel electrophoresis

BACKGROUND: Serum protein analysis in both humans and experimental animal species has so far been carried out by labor-intensive techniques, such as agarose gel electrophoresis (AGE). OBJECTIVE: The objective of this study was to evaluate capillary electrophoresis (CE) as an alternative technique to AGE for the analysis of serum proteins from healthy animals. METHODS: Blood samples were collected into tubes without anticoagulant from 6 fasted healthy male mice, rats, dogs, marmosets, and humans. Serum proteins were separated by CE using a technique standardized for the analysis of human proteins, and the results (efficiency, resolution, and precision) were compared with those obtained through AGE. RESULTS: Compared with AGE, CE resulted in narrower peaks and more peaks. The efficiency of protein separation by CE was significantly higher for all species, and resolution (R) was significantly higher in samples from dogs. Using rat serum, intraday reproducibility was lower for all protein fractions, and interday reproducibility was lower for most peaks, compared with AGE. CONCLUSIONS: We conclude that CE is a viable alternative to AGE for the determination of protein electrophoresis in a routine veterinary clinical pathology laboratory. The minimal sample requirement (2 microL), complete automation, and quantitative results make CE an especially valuable technique for protein analysis in experimental animal models.     

Moraxella bovis hemagglutinins: effect of carbohydrates, heating and erythrocytes.

Several properties of the adhesins of eight isolates of Moraxella bovis recovered from cattle suffering from infectious keratoconjunctivitis, were studied. Adhesions were detected through autoagglutination in saline and hemagglutination. Autoagglutinating strains agglutinated red blood cells of the chicken, rabbit, sheep and swine, but not those of the guinea pig. The adhesins were not inhibited by D-mannose or D-galactose and resisted heating at 100 degrees C for 15 minutes. Magnesium chloride at a final concentration of 10% inhibited autoagglutination and hemagglutination. The value of the hemagglutination test for monitoring synthesis of fimbriae by M. bovis, is discussed.