Patellar Proximo-Distal Displacement following Modified Maquet Technique Is Not Predictive of Patellar Luxation.

OBJECTIVE: The aim of this study was to test the low sensitivity of the Allberg and Miles index to the stifle opening angle, evaluate the displacement of the patella after a Modified Maquet Technique using this index and assess the incidence of patellar luxation post-Modified Maquet Technique in dogs. STUDY DESIGN: Medical records were reviewed from 2012 to 2017. Allberg Miles index were determined for each stifle pre- and postoperatively, as well as the stifle joint opening of each case. Occurrence of patellar luxation was recorded. RESULTS: 137 stifles on 116 dogs were reviewed. The stifle opening angle did not influence the Allberg Miles index. Pre- and postoperative index showed a distal displacement of the patella after a Modified Maquet Procedure, especially at 135° of stifle opening angle. Only 1/137 cases demonstrated patellar luxation after the surgery. CONCLUSION: Based on our statistical analysis, we were able to conclude that within the maximum stifle opening angle range recorded in our series of cases; the Allberg Miles index variation was not significant. While patellar baja is clearly induced by the Modified Maquet Technique, the latter did not seem to predispose patients to post-operative patellar luxation in our study population.

The Major Envelope Glycoprotein of Murid Herpesvirus 4 Promotes Sexual Transmission.

Gammaherpesviruses are important human and animal pathogens. Infection control has proven difficult because the key process of transmission is ill understood. Murid herpesvirus 4 (MuHV-4), a gammaherpesvirus of mice, is transmitted sexually. We show that this depends on the major virion envelope glycoprotein gp150. gp150 is redundant for host entry, and in vitro, it regulates rather than promotes cell binding. We show that gp150-deficient MuHV-4 reaches and replicates normally in the female genital tract after nasal infection but is poorly released from vaginal epithelial cells and fails to pass from the female to the male genital tract during sexual contact. Thus, we show that the regulation of virion binding is a key component of spontaneous gammaherpesvirus transmission.IMPORTANCE Gammaherpesviruses are responsible for many important diseases in both animals and humans. Some important aspects of their life cycle are still poorly understood. Key among these is viral transmission. Here we show that the major envelope glycoprotein of murid herpesvirus 4 functions not in entry or dissemination but in virion release to allow sexual transmission to new hosts.

COMPARISON BETWEEN SEDATION AND GENERAL ANESTHESIA FOR HIGH RESOLUTION COMPUTED TOMOGRAPHIC CHARACTERIZATION OF CANINE IDIOPATHIC PULMONARY FIBROSIS IN WEST HIGHLAND WHITE TERRIERS.

Canine idiopathic pulmonary fibrosis is a progressive interstitial lung disease mainly affecting West Highland white terriers. Thoracic high-resolution computed tomographic (T-HRCT) findings for Canine idiopathic pulmonary fibrosis acquired under general anesthesia have been described previously. However, the use of general anesthesia may be contraindicated for some affected dogs. Sedation may allow improved speed and safety, but it is unknown whether sedation would yield similar results in identification and grading of Canine idiopathic pulmonary fibrosis lesions. The aim of this prospective, observational, method-comparison, case-control study was to compare findings from T-HRCT images acquired under sedation versus general anesthesia for West Highland white terriers affected with Canine idiopathic pulmonary fibrosis (n = 11) and age-matched controls (n = 9), using the glossary of terms of the Fleischner Society and a scoring system. Ground-glass opacity was identified in all affected West Highland white terriers for both sedation and general anesthesia acquisitions, although the Ground-glass opacity extent varied significantly between the two acquisitions (P < 0.001). Ground-glass opacity was the sole lesion observed in control dogs (n = 6), but was less extensive compared with affected West Highland white terriers. Identification and grading of a mosaic attenuation pattern differed significantly between acquisitions (P < 0.001). Identification of lesions such as consolidations, nodules, parenchymal and subpleural bands, bronchial wall thickening, and bronchiectasis did not differ between acquisitions. The present study demonstrated that T-HRCT obtained under sedation may provide different information than T-HRCT obtained under general anesthesia for identification and grading of some Canine idiopathic pulmonary fibrosis lesions, but not all of them. These differences should be taken into consideration when general anesthesia is contraindicated and sedation is necessary for evaluating West Highland white terriers with Canine idiopathic pulmonary fibrosis.

Conserved Fever Pathways across Vertebrates: A Herpesvirus Expressed Decoy TNF-α Receptor Delays Behavioral Fever in Fish.

Both endotherms and ectotherms (e.g., fish) increase their body temperature to limit pathogen infection. Ectotherms do so by moving to warmer places, hence the term "behavioral fever." We studied the manifestation of behavioral fever in the common carp infected by cyprinid herpesvirus 3, a native carp pathogen. Carp maintained at 24°C died from the infection, whereas those housed in multi-chamber tanks encompassing a 24°C-32°C gradient migrated transiently to the warmest compartment and survived as a consequence. Behavioral fever manifested only at advanced stages of infection. Consistent with this, expression of CyHV-3 ORF12, encoding a soluble decoy receptor for TNF-α, delayed the manifestation of behavioral fever and promoted CyHV-3 replication in the context of a temperature gradient. Injection of anti-TNF-α neutralizing antibodies suppressed behavioral fever, and decreased fish survival in response to infection. This study provides a unique example of how viruses have evolved to alter host behavior to increase fitness.

Generation of a soluble recombinant trimeric form of bovine CD40L and its potential use as a vaccine adjuvant in cows.

Vaccination is the most cost-effective way to control infectious diseases in cattle. However, many infectious diseases leading to severe economical losses worldwide still remain for which a really effective and safe vaccine is not available. These diseases are most often due to intracellular pathogens such as bacteria or viruses, which are, by their localization, protected from antibiotics and/or CD4(+) T cell-dependent humoral responses. We therefore postulated that strategies leading to induction of not only CD4(+) T cell responses but also CD8(+) cytotoxic T lymphocyte (CTL) responses against infected cells should be privileged in the development of new vaccines against problematic intracellular pathogens in bovines. CD40 signaling in antigen-presenting cells may lead to the induction of robust CD4-independent CTL responses and several studies, especially in mice, have used CD40 stimulation to promote CD8(+) T cell-mediated immunity. For example, we have recently shown that immunization of mice with heat-killed Staphylococcus aureus (HKSA) and agonistic anti-CD40 monoclonal antibodies elicits strong CTL responses capable of protecting mice from subsequent staphylococcal mastitis. Unfortunately, there is at present no tool available to efficiently stimulate CD40 in cattle. In this study, we therefore first produced a soluble recombinant trimeric form of the natural bovine CD40 ligand (sboCD40LT). We then observed that sboCD40LT was able to potently stimulate bovine cells in vitro. Finally, we provide evidence that immunization of cows with sboCD40LT combined with HKSA was able to significantly increase the number of both HKSA-specific CD4(+) and CD8(+) T cells in the draining lymph nodes. In conclusion, we suggest that this new molecular tool could help in the development of vaccine strategies against bovine diseases caused by intracellular pathogens.

Assessment of CCL2 and CXCL8 chemokines in serum, bronchoalveolar lavage fluid and lung tissue samples from dogs affected with canine idiopathic pulmonary fibrosis.

Canine idiopathic pulmonary fibrosis (CIPF) is a progressive disease of the lung parenchyma that is more prevalent in dogs of the West Highland white terrier (WHWT) breed. Since the chemokines (C-C motif) ligand 2 (CCL2) and (C-X-C motif) ligand 8 (CXCL8) have been implicated in pulmonary fibrosis in humans, the aim of the present study was to investigate whether these same chemokines are involved in the pathogenesis of CIPF. CCL2 and CXCL8 concentrations were measured by ELISA in serum and bronchoalveolar lavage fluid (BALF) from healthy dogs and WHWTs affected with CIPF. Expression of the genes encoding CCL2 and CXCL8 and their respective receptors, namely (C-C motif) receptor 2 (CCR2) and (C-X-C motif) receptor 2 (CXCR2), was compared in unaffected lung tissue and biopsies from dogs affected with CIPF by quantitative PCR and localisation of CCL2 and CXCL8 proteins were determined by immunohistochemistry. Significantly greater CCL2 and CXCL8 concentrations were found in the BALF from WHWTs affected with CIPF, compared with healthy dogs. Significantly greater serum concentrations of CCL2, but not CXCL8, were found in CIPF-affected dogs compared with healthy WHWTs. No differences in relative gene expression for CCL2, CXCL8, CCR2 or CXCR2 were observed when comparing lung biopsies from control dogs and those affected with CIPF. In affected lung tissues, immunolabelling for CCL2 and CXCL8 was observed in bronchial airway epithelial cells in dogs affected with CIPF. The study findings suggest that both CCL2 and CXCL8 are involved in the pathogenesis of CIPF. Further studies are required to determine whether these chemokines might have a clinical use as biomarkers of fibrosis or as targets for therapeutic intervention.

Functional analysis of the three HMA4 copies of the metal hyperaccumulator Arabidopsis halleri.

In Arabidopsis halleri, the HMA4 gene has an essential function in Zn/Cd hypertolerance and hyperaccumulation by mediating root-to-shoot translocation of metals. Constitutive high expression of AhHMA4 results from a tandem triplication and cis-activation of the promoter of all three copies. The three AhHMA4 copies possess divergent promoter sequences, but highly conserved coding sequences, and display identical expression profiles in the root and shoot vascular system. Here, an AhHMA4::GFP fusion was expressed under the control of each of the three A. halleri HMA4 promoters in a hma2hma4 double mutant of A. thaliana to individually examine the function of each AhHMA4 copy. The protein showed non-polar localization at the plasma membrane of the root pericycle cells of both A. thaliana and A. halleri. The expression of each AhHMA4::GFP copy complemented the severe Zn-deficiency phenotype of the hma2hma4 mutant by restoring root-to-shoot translocation of Zn. However, each copy had a different impact on metal homeostasis in the A. thaliana genetic background: AhHMA4 copies 2 and 3 were more highly expressed and provided higher Zn tolerance in roots and accumulation in shoots than copy 1, and AhHMA4 copy 3 also increased Cd tolerance in roots. These data suggest a certain extent of functional differentiation among the three A. halleri HMA4 copies, stemming from differences in expression levels rather than in expression profile. HMA4 is a key node of the Zn homeostasis network and small changes in expression level can have a major impact on Zn allocation to root or shoot tissues.

Training modifies innate immune responses in blood monocytes and in pulmonary alveolar macrophages.

In humans, strenuous exercise causes increased susceptibility to respiratory infections associated with down-regulated expression of Toll-like receptors (TLRs) and costimulatory and antigen-presenting molecules. Lower airway diseases are also a common problem in sport and racing horses. Because innate immunity plays an essential role in lung defense mechanisms, we assessed the effect of acute exercise and training on innate immune responses in two different compartments. Blood monocytes and pulmonary alveolar macrophages (PAMs) were collected from horses in untrained, moderately trained, intensively trained, and deconditioned states before and after a strenuous exercise test. The cells were analyzed for TLR messenger ribonucleic acid (mRNA) expression by real-time PCR in vitro, and cytokine production after in vitro stimulation with TLR ligands was measured by ELISA. Our results showed that training, but not acute exercise, modified the innate immune responses in both compartments. The mRNA expression of TLR3 was down-regulated by training in both cell types, whereas the expression of TLR4 was up-regulated in monocytes. Monocytes treated with LPS and a synthetic diacylated lipoprotein showed increased cytokine secretion in trained and deconditioned subjects, indicating the activation of cells at the systemic level. The production of TNF-α and IFN-ß in nonstimulated and stimulated PAMs was decreased in trained and deconditioned horses and might therefore explain the increased susceptibility to respiratory infections. Our study reports a dissociation between the systemic and the lung response to training that is probably implicated in the systemic inflammation and in the pulmonary susceptibility to infection.

Associations between properties linked with persistence in a collection of Staphylococcus aureus isolates from bovine mastitis.

Staphylococcus aureus is recognized worldwide as a pathogen causing many serious diseases in humans and animals, and is one of the most important etiological agents of clinical and subclinical bovine mastitis. The aim of the present study was to investigate and correlate properties, that may be associated with persistent mastitis, of S. aureus strains isolated from milk of cows suffering from mastitis: (i) expression of capsular antigens (CP5 or CP8) by specific ELISA; (ii) intracellular survival by invasion of MAC-T cells; and (iii) biofilm production by spectrophotometry analysis after growth in TSBglc. The results showed that (i) the proportion of strains expressing capsular antigen was higher in cap8- than in cap5-positive isolates; (ii) a correlation was observed between the capsular profile and the intracellular survival as well as the biofilm production; and (iii) the capsular profile, biofilm production and intracellular survival were associated with only two agr-groups. Statistical and clustering analysis allowed us to establish different profiles that could be associated with in vivo persistence. Indeed, isolates belonging to agr group II, expressing the capsular antigen CP8 and showing low intracellular survival are probably better adapted to an extracellular niche. Conversely, isolates belonging to agr group I that do not express any capsular antigen (CP5 or CP8) but show high intracellular survival are probably better adapted to an intracellular niche.

Experimental model of equine alveolar macrophage stimulation with TLR ligands.

Pulmonary diseases are common in horses and have a major economic impact on the equine industry. Some of them could be associated with an inadequate immune response in the lung, but methods to evaluate this response in horses are lacking. The aim of this study was to develop and validate an experimental model that could be applied in several physiological and pathological conditions to assess the innate immune response of equine pulmonary cells. Equine alveolar macrophages (AMs) obtained from bronchoalveolar lavages were isolated from other cells by adhesion. TLR2, 3, and 4 expression in AMs was studied and their responses to commercial ligands (respectively FSL-1, Poly(I:C), and LPS) were evaluated after determination of the appropriate dose and time of incubation. TLR responses were assessed by measuring cytokine production using (1) gene expression of TNFα, IFNß, Il-1ß, and IFNα by qPCR (indirect method); and (2) cytokine production for TNFα and IFNß by ELISA (direct method). TLR 2, 3, and 4 were expressed by AMs. TLR 2 stimulation with 10 ng/mL of FSL-1 during 3h significantly increased IL-1ß and TNFα gene expression. TLR 3 stimulation with 1000 ng/mL of Poly(I:C) during 1h increased IFNß, IFNα, Il-1ß and TNFα expression. TLR 4 stimulation with 100 ng/mL of LPS during 3h increased TNFα, IFNß, and Il-1ß expression. Results obtained by ELISA quantification of TNFα and IFNß produced by AMs following stimulation during 6h were similar: FSL-1 increased TNFα production but not IFNß, Poly(I:C) and LPS increased production of IFNß and TNFα. In conclusion, pulmonary innate immunity of horses can be assessed ex vivo by measuring cytokine production following stimulation of AMs with TLR agonists. This experimental model could be applied under several conditions especially to improve the understanding of equine respiratory disease pathogenesis, and to suggest novel therapeutic opportunities.

Urodynamic and morphometric characteristics of the lower urogenital tracts of female Beagle littermates during the sexually immature period and first and second estrous cycles.

OBJECTIVE: To compare values of lower urogenital tract urodynamic and morphometric variables determined during the prepubertal (sexually immature) period and first and second estrous cycles in healthy female Beagle littermates to determine functional and anatomic changes of the lower urogenital tract during those periods. ANIMALS: 5 female Beagle littermates. PROCEDURES: Urethral pressure profilometry, diuresis cystometry, and vaginourethrography were performed when dogs were 3.5, 4.5, 5, 6, 7, 8, 8.5, and 9 months old and during proestrus; estrus; early, middle, and late diestrus; and early and late anestrus of the first and second estrous cycles. RESULTS: At the end of the prepubertal period, values of urodynamic and morphometric variables increased significantly, compared with values at earlier times. Maximum bladder capacity developed when dogs were 9 months old. In all dogs, the bladder was intermittently located in an intrapelvic position during the prepubertal period; the bladder was intra-abdominal from the time dogs were 9 months old until the end of the study. Urethral pressure decreased significantly during estrus and early diestrus of the first and second estrous cycles. Bladder capacity increased significantly during diestrus of both estrous cycles. Urethral and vaginal lengths were significantly longer during proestrus and estrus than they were during anestrus. CONCLUSIONS AND CLINICAL RELEVANCE: Values of lower urogenital tract urodynamic and morphometric variables were influenced by age and phases of the estrous cycle of immature and young adult Beagles in this study. Age of dog and phase of estrous cycle should be considered when interpreting urodynamic and vaginourethrography data.

Increased hypoxia-inducible factor 1α expression in lung cells of horses with recurrent airway obstruction.

BACKGROUND: Recurrent airway obstruction (RAO, also known as equine heaves) is an inflammatory condition caused by exposure of susceptible horses to organic dusts in hay. The immunological processes responsible for the development and the persistence of airway inflammation are still largely unknown. Hypoxia-inducible factor (Hif) is mainly known as a major regulator of energy homeostasis and cellular adaptation to hypoxia. More recently however, Hif also emerged as an essential regulator of innate immune responses. Here, we aimed at investigating the potential involvement of Hif1-α in myeloid cells in horse with recurrent airway obstruction. RESULTS: In vitro, we observed that Hif is expressed in equine myeloid cells after hay dust stimulation and regulates genes such as tumor necrosis factor alpha (TNF-α), interleukin-8 (IL-8) and vascular endothelial growth factor A (VEGF-A). We further showed in vivo that airway challenge with hay dust upregulated Hif1-α mRNA expression in myeloid cells from the bronchoalveolar lavage fluid (BALF) of healthy and RAO-affected horses, with a more pronounced effect in cells from RAO-affected horses. Finally, Hif1-α mRNA expression in BALF cells from challenged horses correlated positively with lung dysfunction. CONCLUSION: Taken together, our results suggest an important role for Hif1-α in myeloid cells during hay dust-induced inflammation in horses with RAO. We therefore propose that future research aiming at functional inactivation of Hif1 in lung myeloid cells could open new therapeutic perspectives for RAO.

Effect of strenuous exercise and ex vivo TLR3 and TLR4 stimulation on inflammatory gene expression in equine pulmonary leukocytes.

The effects of strenuous exercise and ex vivo stimulation of TLR3 and TLR4 pathways on the expression of six inflammatory genes in equine pulmonary leukocytes were investigated. The genes tested were interferon-beta (IFN-ß), interleukin-1-beta (IL-1ß), interleukin-6 (IL-6), interferon gamma-induced protein 10 (IP-10), chemokine (c-c motif) ligand 5 (RANTES) and tumor necrosis factor-alpha (TNF-α). We hypothesized that strenuous exercise would modulate basal gene expression on one hand and modulate the response to bacterial lipopolysaccharide (LPS) and to polyinosinic:polycytidylic acid (Poly IC) on the other hand. Eight young Thoroughbred mares were selected for the experiment. Bronchoalveolar lavages were performed on horses 48 h before and 24h after the completion of treadmill exercise until fatigue. Differential counts were performed on the bronchoalveolar lavage cells. Real-time PCR was used to quantify cytokine expression in pulmonary leukocytes. Target gene expression was normalized to the expression of three housekeeping genes (HKG). There were no significant differences in the mRNA expression of the six cytokines between pre-exercise and post-exercise cells. LPS and Poly IC induced respectively significant increases of TNF-α, IFN-ß, IL-6, IL-1ß, and TNF-α, IFN-ß, IP-10 and RANTES, both before and after exercise. However, exercise induced a significant decrease of the genes response to LPS and Poly IC. These findings may suggest that strenuous treadmill exercise exerts a deleterious effect on part of the pulmonary immune response in horses 24h following an intense physical activity.

CD40 triggering induces strong cytotoxic T lymphocyte responses to heat-killed Staphylococcus aureus immunization in mice: a new vaccine strategy for staphylococcal mastitis.

Staphylococcus (S.) aureus is a major pathogen involved in chronic bovine mastitis. Staphylococcal mastitis is difficult to control due to the ability of S. aureus to invade and survive within host cells. We therefore postulated that induction of CD8(+) cytotoxic T lymphocyte (CTL) responses leading to destruction of infected cells could help in the control of S. aureus mastitis. We demonstrate that immunization of mice with heat-killed S. aureus together with agonistic anti-CD40 monoclonal antibodies elicits strong CTL responses capable of reducing the severity of subsequent staphylococcal mastitis. Our study shows promise for CTL-dependent vaccination against S. aureus mastitis.

Malignant catarrhal fever induced by alcelaphine herpesvirus 1 is associated with proliferation of CD8+ T cells supporting a latent infection.

Alcelaphine herpesvirus 1 (AlHV-1), carried by wildebeest asymptomatically, causes malignant catarrhal fever (WD-MCF) when cross-species transmitted to a variety of susceptible species of the Artiodactyla order. Experimentally, WD-MCF can be induced in rabbits. The lesions observed are very similar to those described in natural host species. Here, we used the rabbit model and in vivo 5-Bromo-2'-Deoxyuridine (BrdU) incorporation to study WD-MCF pathogenesis. The results obtained can be summarized as follows. (i) AlHV-1 infection induces CD8(+) T cell proliferation detectable as early as 15 days post-inoculation. (ii) While the viral load in peripheral blood mononuclear cells remains below the detection level during most of the incubation period, it increases drastically few days before death. At that time, at least 10% of CD8(+ )cells carry the viral genome; while CD11b(+), IgM(+) and CD4(+) cells do not. (iii) RT-PCR analyses of mononuclear cells isolated from the spleen and the popliteal lymph node of infected rabbits revealed no expression of ORF25 and ORF9, low or no expression of ORF50, and high or no expression of ORF73. Based on these data, we propose a new model for the pathogenesis of WD-MCF. This model relies on proliferation of infected CD8(+) cells supporting a predominantly latent infection.

Novel Crohn disease locus identified by genome-wide association maps to a gene desert on 5p13.1 and modulates expression of PTGER4.

To identify novel susceptibility loci for Crohn disease (CD), we undertook a genome-wide association study with more than 300,000 SNPs characterized in 547 patients and 928 controls. We found three chromosome regions that provided evidence of disease association with p-values between 10(-6) and 10(-9). Two of these (IL23R on Chromosome 1 and CARD15 on Chromosome 16) correspond to genes previously reported to be associated with CD. In addition, a 250-kb region of Chromosome 5p13.1 was found to contain multiple markers with strongly suggestive evidence of disease association (including four markers with p < 10(-7)). We replicated the results for 5p13.1 by studying 1,266 additional CD patients, 559 additional controls, and 428 trios. Significant evidence of association (p < 4 x 10(-4)) was found in case/control comparisons with the replication data, while associated alleles were over-transmitted to affected offspring (p < 0.05), thus confirming that the 5p13.1 locus contributes to CD susceptibility. The CD-associated 250-kb region was saturated with 111 SNP markers. Haplotype analysis supports a complex locus architecture with multiple variants contributing to disease susceptibility. The novel 5p13.1 CD locus is contained within a 1.25-Mb gene desert. We present evidence that disease-associated alleles correlate with quantitative expression levels of the prostaglandin receptor EP4, PTGER4, the gene that resides closest to the associated region. Our results identify a major new susceptibility locus for CD, and suggest that genetic variants associated with disease risk at this locus could modulate cis-acting regulatory elements of PTGER4.

The TNF/ADAM 17 system: implication of an ADAM 17 haplotype in the clinical response to infliximab in Crohn's disease.

Infliximab, a chimeric anti-tumour necrosis factor (TNF)-alpha antibody induces a clinical response in 70% of Crohn's disease patients and the response to infliximab therapy could be partially determined by genetic factors. The implication of both transmembrane and soluble forms of the TNF-alpha in the mechanism of action of infliximab has been demonstrated. The aim of our work was first to perform a complete study of TNF variants role in the response to infliximab in Crohn's disease. Secondly, considering the role of ADAM 17 in TNF-alpha shedding, the ADAM 17 locus was also studied. The response to infliximab was evaluated in 222 Caucasian Crohn's disease patients with a luminal (n=160) or fistulizing (n=62) form of the disease. Clinical and biological response evaluation was based on the Crohn's Disease Activity Index score and C-reactive protein level evolutions, respectively. The entire TNF gene was sequenced on the complete cohort. Twelve single nucleotide polymorphisms spanning the ADAM 17 locus were studied and haplotypes rebuilt. A clinical response was observed in 64% of the patients and biological response in 77.1% of patients. No association was found between the TNF gene and the response to infliximab. One haplotype in the ADAM 17 region was associated with a clinical response to infliximab in CD patients (adjusted P=0.045). In conclusion, our results exclude, with a reasonable power, an implication of the TNF gene in the response to infliximab in Crohn's disease, but reveal a potential role of the ADAM 17 gene in this response.

Intraspecific bovine herpesvirus 1 recombinants carrying glycoprotein E deletion as a vaccine marker are virulent in cattle.

Vaccines used in control programmes of Bovine herpesvirus 1 (BoHV-1) utilize highly attenuated BoHV-1 strains marked by a deletion of the glycoprotein E (gE) gene. Since BoHV-1 recombinants are obtained at high frequency in experimentally coinfected cattle, the consequences of recombination on the virulence of gE-negative BoHV-1 were investigated. Thus, gE-negative BoHV-1 recombinants were generated in vitro from several virulent BoHV-1 and one mutant BoHV-1 deleted in the gC and gE genes. Four gE-negative recombinants were tested in the natural host. All the recombinants were more virulent than the gE-negative BoHV-1 vaccine and the gC- and gE-negative parental BoHV-1. The gE-negative recombinant isolated from a BoHV-1 field strain induced the highest severe clinical score. Latency and reactivation studies showed that three of the recombinants were reexcreted. Recombination can therefore restore virulence of gE-negative BoHV-1 by introducing the gE deletion into a different virulence background.

Urodynamic and morphologic changes in the lower portion of the urogenital tract after administration of estriol alone and in combination with phenylpropanolamine in sexually intact and spayed female dogs.

OBJECTIVE: To compare the urodynamic and morphologic effects of the administration of estriol alone and in combination with phenylpropanolamine on the lower portion of the urogenital tract in female dogs. ANIMALS: 3 sexually intact and 3 spayed female Beagles without urinary incontinence. PROCEDURE: Dogs received estriol (2 mg, PO) once daily for 7 days followed by estriol (2 mg, PO) and phenylpropanolamine (1.5 mg/kg, PO) once daily for 7 days. Urethral pressure profilometry, diuresis cystometry, and vaginourethrography were performed before treatment (day 0) and at days 7 and 14. The maximum urethral pressure (MUP) and closure pressure (MUCP), urethral functional and anatomic profile lengths, integrated pressure (IP), plateau, distance before MUP, maximum meatus pressure, threshold pressure, threshold volume, compliance, urethral length, and vaginal length and width were measured. RESULTS: Before treatment, no urodynamic differences were observed between the 2 groups; however, vaginal length and width were significantly shorter in spayed dogs. Compared with day 0 values, estriol treatment significantly increased MUP, MUCP, and IP values at day 7, but at day 14, this effect decreased despite phenylpropanolamine administration. No morphologic changes from baseline were detected after either treatment in any dog. CONCLUSIONS AND CLINICAL RELEVANCE: Data suggest that estriol mainly acts on the urethral sphincter mechanism by increasing urethral resistance in sexually intact and spayed female dogs without urinary incontinence. Administration of estriol and phenylpropanolamine did not increase the urethral resistance more than estriol alone. The urodynamic effects of estriol in female dogs with urinary incontinence remain to be elucidated.