Current Veterinary-medicine- News Results

Cell-cycle regulators cdk2ap1 and bicalutamide suppress malignant biological interactions between prostate cancer and bone cells.

Prostate. 2010 Sep 1;
Zolochevska O, Figueiredo ML

INTRODUCTION: We examined whether the novel cell-cycle regulator cdk2-associated protein 1 (p12(cdk2ap1) or cdk2ap1), recently shown to regulate prostate cancer cell cycle and apoptosis, could have the capacity to reduce invasiveness and/or reduce malignant biological interactions between prostate cancer and bone cells. We also examined whether combining two cell-cycle arrest stimuli, cdk2ap1 plus bicalutamide (or casodex, CDX), could help enhance inhibition of prostate cancer cell phenotypes. METHODS: We stably expressed cdk2ap1 in prostate cancer cell lines using lentiviral vectors, as well as several different co-culture assays to quantify cellular invasion, migration, and the effect of the treatments on interaction with the bone microenvironment. RESULTS: We have determined that cdk2ap1 can further augment the effects of CDX on cell-cycle arrest, growth inhibition, and cellular invasion. Using a coculture model, we observed that either cdk2ap1 or cdk2ap1/CDX combination were able to reduce chemotaxis towards osteoblasts, and also reduce the osteoblastic proliferative response to prostate cancer. Also modified by cdk2ap1 and CDX were several signaling pathways associated with prostate cancer/bone crosstalk mechanisms involved in prostate cancer progression. CONCLUSIONS: These results suggest that either cdk2ap1 or the cdk2ap1/CDX combination hold promise in regulating prostate cancer growth and malignant phenotypes, and potentially also in reducing procarcinogenic interactions with a bone microenvironment model, restoring malignant phenotypes and signaling to a more benign state. Prostate (c) 2010 Wiley-Liss, Inc.

Hepatocellular carcinoma and the underlying mechanisms.

Afr Health Sci. 2010 Mar; 10(1): 93-8
Oyagbemi A, Azeez O, Saba A

The incidence of hepatocellular carcinoma is increasing worldwide as well as the associated risk factors, some of which include exposure to aflatoxin B1, Hepatitis B (HBV) virus and hepatitis C (HCV) virus. Mutation of tumour suppressor gene p53 at codon 249(ser) at exon 7 has been found to contribute significantly to replication of damaged DNA and subsequent tumour progression. The x gene of HBV (HBx) is the most common open reading frame integrated into the host genome in hepatocellular carcinoma and the integrated HBx is frequently mutated in hepatocellular carcinoma. Mutant HBx proteins still retain their ability to bind to p53 thereby attenuating DNA repair and p53-mediated apoptosis.

Decreased Concentration and Enhanced Metabolism of Sphingosine-1-Phosphate in Lesional Skin of Dogs with Atopic Dermatitis: Disturbed Sphingosine-1-Phosphate Homeostasis in Atopic Dermatitis.

J Invest Dermatol. 2010 Sep 2;
Bäumer W, Roßbach K, Mischke R, Reines I, Langbein-Detsch I, Lüth A, Kleuser B

Associative plasticity at excitatory synapses facilitates recruitment of fast-spiking interneurons in the dentate gyrus.

J Neurosci. 2010 Sep 1; 30(35): 11826-37
Sambandan S, Sauer JF, Vida I, Bartos M

Fast-spiking perisomatic-inhibitory interneurons (PIIs) receive convergent excitation and mediate both feedforward and feedback inhibition in cortical microcircuits. However, it remains poorly understood how convergent excitatory inputs recruit PIIs to produce precisely timed inhibition. Here, we analyzed the interaction of inputs from the entorhinal cortex [perforant path (PP)] and from local granule cells [mossy fibers (MFs)] onto PIIs in the rat dentate gyrus (DG). PP stimulation alone activates PIIs with low temporal precision. Interestingly, when PP and MFs are coactivated with a 10 ms delay, PIIs discharge with precise timing. Moreover, repeated coactivation of the two inputs induces associative long-term potentiation (LTP) at MF synapses. Under these conditions, a single potentiated MF input is sufficient to recruit PIIs in a reliable and highly precise manner to provide feedback inhibition. MF-LTP depends on the discharge of PIIs, indicating Hebbian plasticity. However, MF-LTP is preserved when NMDA receptors are blocked but depends on transmission through Ca(2+)-permeable AMPA receptors (AMPARs). PP-PII synapses, in contrast, lack Ca(2+)-permeable AMPARs and do not show plasticity on associative activation. Thus, precise recruitment of PIIs requires excitation through MF-PII synapses during feedforward activation. We propose that associative plasticity at these synapses is a central mechanism that adjusts inhibition levels to maintain sparse activity and to improve signal-to-noise ratio in the DG network.

Prolonged Co-circulation of Two Distinct Dengue Virus Type 3 Lineages in the Hyperendemic Area of Medellin, Colombia.

Am J Trop Med Hyg. 2010 Sep; 83(3): 672-8
Ospina MC, Diaz FJ, Osorio JE

During the past two decades, Dengue virus-3 (DENV-3) has re-emerged in the Western Hemisphere causing significant epidemics of dengue fever (DF) and dengue hemorrhagic fever (DHF). In an effort to understand the molecular evolution of DENV-3 and their relationships to other DENV-3 circulating in the western hemisphere, we conducted a phylogenetic study on DENV-3 isolates made between 2002 and 2007 in the metropolitan area of Medellín, Colombia. An unexpected co-circulation of two different variants of DENV-3 subtype III during at least 5 years in Medellín was found. In addition, a more complete analysis of DENV-3 viruses isolated in other South American regions revealed the existence of three different subtype III lineages, all derived from independent introductions. This study documents significant genetic diversity of circulating viruses within the same subtype and an unusual capacity of the population of this city to support continuous circulation of multiple variants of dengue virus.

Infectivity, Pathogenicity, and Virulence of Trypanosoma cruzi Isolates from Sylvatic Animals and Vectors, and Domestic Dogs from the United States in ICR Strain Mice and SD Strain Rats.

Am J Trop Med Hyg. 2010 Sep; 83(3): 519-22
Roellig DM, Yabsley MJ

Trypanosoma cruzi, the causative agent of Chagas disease, is widespread in the southern United States. In addition to detection in numerous wildlife host species, cases have been diagnosed in domestic dogs and humans. In the current investigation, groups of laboratory mice [Crl:CD1 (ICR)] were inoculated with one of 18 United States T. cruzi isolates obtained from a wide host range to elucidate their infectivity, pathogenicity, and virulence. In addition, laboratory rats (SD strain) were inoculated with four isolates. Mice and rats were susceptible to infection with all strains, but no morbidity or mortality was noted, which indicates that these T. cruzi isolates from the United States had low virulence for laboratory mice and rats.

Efficient differentiation of Mycobacterium avium complex species and subspecies using a five-target multiplex polymerase chain reaction.

J Clin Microbiol. 2010 Sep 1;
Shin SJ, Lee BS, Koh WJ, Manning EJ, Anklam K, Sreevatsan S, Lambrecht RS, Collins MT

Infections caused by Mycobacterium avium complex (MAC) are on the rise in both human and veterinary medicine. A means of effectively discriminating amongst closely related yet pathogenetically diverse members of MAC would enable better diagnosis and treatment as well as further our understanding of the epidemiology of these pathogens. In this report, a five-target multiplex PCR designed to discriminate MAC organisms isolated from liquid media cultures was developed. This MAC multiplex was designed to amplify a 16s rDNA target common to all Mycobacterium species, a chromosomal target unique to M. avium subsp. avium (MAA) serotypes 2 and 3, M. avium subsp. silvaticum (MAS) and M. intracellulare called DT1, plus three insertion sequences, IS900, IS901, and IS1311. The pattern of amplification results allowed determination if isolates were mycobacteria, members of the MAC, and if they belonged to one of three major MAC subspecies, M. a. paratuberculosis (MAP), M. a. avium (MAA), or M. a. hominissuis (MAH). Analytical sensitivity was 10 fg of MAP genomic DNA, 5-10 fg MAA genomic DNA, and 2-5 fg DNA from other mycobacterial species. Identification accuracy of the MAC multiplex was evaluated by testing 53 bacterial reference strains consisting of 28 different mycobacterial species and 12 non-mycobacterial species. Identification accuracy in a clinical setting was evaluated for 223 clinical MAC isolates independently identified by other methods. Isolate identification agreement between the MAC multiplex and these comparison assays was 100%. The novel MAC multiplex is a rapid, reliable, and simple assay for discriminating among MAC species and subspecies in liquid culture media.

Impact of long-term storage on the stability of standard DNA for nucleic acid based methods.

J Clin Microbiol. 2010 Sep 1;
Röder B, Frühwirth K, Vogl C, Wagner M, Rossmanith P

Real-time PCR is dependent upon a calibration function for quantification. While long-term storage of standards saves cost and time, solutions of DNA are prone to degradation. We present here the benchmark treatment for preservation of DNA-standards, involving storage in 50%-glycerol/ddH2O, whereby a deviation of 0.2 Ct-values resulted after 100-day storage.

Cytotoxicity of ORF3-proteins from a non-pathogenic and a pathogenic Porcine circovirus.

J Virol. 2010 Sep 1;
Chaiyakul M, Hsu K, Dardari R, Marshall F, Czub M

Porcine circovirus type 2 (PCV2) infection is associated with significant and serious swine diseases worldwide while PCV1 appears to be non-pathogenic. Previous studies demonstrated that ORF3 protein of PCV2 (PCV2ORF3) was involved in PCV2 pathogenesis via its pro-apoptotic capability (Liu et al. 2006). If PCV2ORF3-induced apoptosis is a determinant of virulence, PCV1ORF3 is hypothesized to lack this ability. Properties of PCV1 and PCV2 ORF3, expressed as fusion proteins to an enhanced green fluorescent protein (eGFP), were characterized with regard to their ability to cause cellular morphological changes, detachment, death and apoptosis. PCV1ORF3 significantly induced more apoptotic cell death and was toxic to more different cell types than PCV2ORF3. PCV1ORF3 associated-cell death was caspase-dependent. PCV1ORF3 also induced poly(ADP-ribose) polymerase-1 (PARP) cleavage; however whether PARP was involved in cell death requires further studies. Truncation of PCV1 and elongation of PCV2 ORF3 proteins revealed that the first 104 amino acids (aa) contain a domain capable of inducing cell death, whereas the C-terminus of PCV1ORF3 contains a domain possibly responsible for enhancing cell death. These results suggest that the pathogenicity of PCV2 for pigs is either not or not solely determined by the ORF3 protein.

Development of a Bacillus subtilis-based Rotavirus Vaccine.

Clin Vaccine Immunol. 2010 Sep 1;
Lee S, Belitsky BR, Brinker JP, Kerstein KO, Brown DW, Clements JD, Keusch GT, Tzipori S, Sonenshein AL, Herrmann JE

Bacillus subtilis vaccine strains engineered to express either group A bovine or murine rotavirus VP6 were tested in adult mice for their ability to induce immune responses and provide protection against rotavirus challenge. Mice were inoculated intranasally with spores or vegetative cells of the recombinant strains of B. subtilis. To enhance mucosal immunity, whole cholera toxin (CT) or a mutant form (R192G) of Escherichia coli heat labile toxin (mLT) were included as adjuvants. To evaluate vaccine efficacy, the immunized mice were challenged orally with EDIM EW murine rotavirus and monitored daily for 7 days for virus shedding in feces. Mice immunized with either VP6 spore or VP6 vegetative cell vaccines raised serum anti-VP6 IgG ELISA titers, whereas only the VP6 spore vaccines generated fecal anti-VP6 IgA ELISA titers. Mice in groups that were immunized with VP6 spore vaccines plus CT or mLT showed a significant reduction in virus shedding, whereas the groups of mice immunized with VP6 vegetative cell vaccines showed no difference in virus shedding compared with mice immunized with control spores or cells. These results demonstrate that intranasal inoculation with B. subtilis spore-based rotavirus vaccines is effective in generating protective immunity against rotavirus challenge in mice.

Strain variation in Mycoplasma agassizii and distinct host antibody responses explain differences between ELISA and Western blot assays.

Clin Vaccine Immunol. 2010 Sep 1;
Wendland LD, Klein PA, Jacobson ER, Brown MB

The precarious status of desert (Gopherus agassizii) and gopher (G. polyphemus) tortoises has resulted in conservation efforts that now include health assessment as an important component of management decision-making. Mycoplasmal upper respiratory tract disease (URTD) is one of very few diseases in chelonians for which comprehensive and rigorously validated diagnostic tests exist. In this study, sera obtained from eight Gopherus tortoises documented at necropsy to (i) be ELISA seropositive using the PS6 antigen, (ii) be infected with M. agassizii as indicated by direct isolation of the pathogen from the respiratory surfaces, and (iii) to have histological lesions of mycoplasmal URTD, were used to evaluate four distinct clinical isolates of M. agassizii as antigens for ELISA and Western blot analyses. Each animal reacted in the Western blot with its homologous M. agassizii strain, but recognition of heterologous M. agassizii strains was variable. Further, individual animals varied significantly with respect to the specific proteins recognized by the humoral immune response. An additional 114 Gopherus serum samples were evaluated using ELISA antigens prepared from the four distinct M. agassizii strains; A405 values were significantly correlated (r(2) Goodness of Fit range = 0.708 to 0.771, P<0.0001) for all antigens tested. The results confirm that strain variation is responsible for the observed differences between Western blot binding patterns. Thus, reliance on a single M. agassizii strain as antigen in Western blot assays may provide false negative results. This could have adverse consequences for the well being of these environmentally sensitive hosts if false-negative animals were relocated to sites consisting of true-negative populations.

Suppression of NF-{kappa}B Increases Bone Formation and Ameliorates Osteopenia in Ovariectomized Mice.

Endocrinology. 2010 Sep 1;
Alles N, Soysa NS, Hayashi J, Khan M, Shimoda A, Shimokawa H, Ritzeler O, Akiyoshi K, Aoki K, Ohya K

Bone degenerative diseases, including osteoporosis, impair the fine balance between osteoclast bone resorption and osteoblast bone formation. Single-agent therapy for anabolic and anticatabolic effects is attractive as a drug target to ameliorate such conditions. Inhibition of nuclear factor (NF)-kappaB reduces the osteoclast bone resorption. The role of NF-kappaB inhibitors on osteoblasts and bone formation, however, is minimal and not well investigated. Using an established NF-kappaB inhibitor named S1627, we demonstrated that inhibition of NF-kappaB increases osteoblast differentiation and bone formation in vitro by up-regulating the mRNAs of osteoblast-specific genes like type I collagen, alkaline phosphatase, and osteopontin. In addition, S1627 was able to increase bone formation and repair bone defect in a murine calvarial defect model. To determine the effect of NF-kappaB on a model of osteoporosis, we injected two doses of inhibitor (25 and 50 mg/kg . d) twice a day in sham-operated or ovariectomized 12-wk-old mice and killed them after 4 wk. The anabolic effect of S1627 on trabecular bone was determined by micro focal computed tomography and histomorphometry. Bone mineral density of inhibitor-treated ovariectomized animals was significantly increased compared with sham-operated mice. Osteoblast-related indices like osteoblast surface, mineral apposition rate, and bone formation rate were increased in S1627-treated animals in a dose-dependent manner. NF-kappaB inhibition by S1627 increased the trabecular bone volume in ovariectomized mice. Furthermore, S1627 could inhibit the osteoclast number, and osteoclast surface to bone surface. In vitro osteoclastogenesis and bone resorbing activity were dose-dependently reduced by NF-kappaB inhibitor S1627. Taken collectively, our results suggest that NF-kappaB inhibitors are effective in treating bone-related diseases due to their dual anabolic and antiresorptive activities.

Aortic body tumor in full-sibling english bulldogs.

J Am Anim Hosp Assoc. 2010 Sep-Oct; 46(5): 366-70
Shaw TE, Harkin KR, Nietfeld J, Gardner JJ

A 10-year-old, neutered male English bulldog died acutely from respiratory distress after a short history of progressive dyspnea. Less than 2 months later, a spayed female full sibling of that dog died suddenly during a nail trim. An aortic body tumor was the cause of death in both dogs based on postmortem and histological examinations. A pheochromocytoma was also diagnosed in the neutered male. Neither dog had a history of brachycephalic airway syndrome, and the implication for a genetic predisposition toward the development of paraganglioma is discussed. This is the first case report of aortic body tumors in sibling dogs, although the condition may not be an uncommon phenomenon.

Porcine small intestinal submucosa augmentation urethroplasty and balloon dilatation of a urethral stricture secondary to inadvertent prostatectomy in a dog.

J Am Anim Hosp Assoc. 2010 Sep-Oct; 46(5): 358-65
Powers MY, Campbell BG, Weisse C

A 10-month-old, male German shepherd dog experienced inadvertent prostatectomy during cryptorchidectomy. Cystourethral anastomosis was performed 1 day later. The dog developed stranguria and incontinence. A proximal urethral stricture was diagnosed with a contrast urethrogram 5 weeks later. Urethral augmentation with an onlay graft of porcine small intestinal submucosa was performed. Urinary diversion was accomplished with a urethral catheter followed by a cystostomy tube. The stricture recurred over the next 6 weeks. Three urethral balloon dilatations were performed 3 days apart, with the third attempt resulting in expansion of the stricture. Twenty-two months postdilatation, the dog intermittently urinated with a steady stream and had mild to moderate urinary incontinence.

Feline hypertrophic osteopathy: a collection of seven cases in taiwan.

J Am Anim Hosp Assoc. 2010 Sep-Oct; 46(5): 346-52
Huang CH, Jeng CR, Lin CT, Yeh LS

Between October 2003 and May 2004, seven cats were diagnosed with severe and extensive hypertrophic osteopathy of the appendicular skeleton without detectable underlying causes. All cats showed similar clinical signs of pain with progressive lameness of the limbs. One cat died shortly after presentation, whereas conditions of the others resolved after medical treatment and a change in diet. Regression of the bone lesions was observed radiographically in all surviving six cases.

Diaphragmatic support of a thoracic wall defect in a dog.

J Am Anim Hosp Assoc. 2010 Sep-Oct; 46(5): 341-5
Hall A, Dujowich M, Merkley DF

A large, caudal thoracic mass was removed along with ribs 11 and 12, resulting in an approximate 16 x 14-cm, caudal thoracic wall defect in a dog. The diaphragmatic musculature was mobilized and used to support the thoracic wall defect. To our knowledge, this method of thoracic wall repair has not been previously reported. This procedure allowed for airtight closure of the thoracic cavity, provided physical support, eliminated the need for muscle flaps or commercially available meshes, and provided a good cosmetic appearance without negatively affecting the dog's athletic performance.

Use of propentofylline in feline bronchial disease: prospective, randomized, positive-controlled study.

J Am Anim Hosp Assoc. 2010 Sep-Oct; 46(5): 318-26
Stursberg U, Zenker I, Hecht S, Hartmann K, Schulz BS

Propentofylline is a methylxanthine derivative with bronchodilating actions similar to those of theophylline. Nineteen cats with bronchial disease were enrolled in this study. All cats received a low dose of prednisolone; 10 of the cats additionally received propentofylline. Propentofylline-treated cats significantly improved in their auscultation scores, respiratory pattern scores, and radiological bronchial markings score over the observation period, and they coughed less and slept less at the end of the study. No significant changes were noted in the control group. This study provides evidence that a combination therapy with prednisolone and propentofylline in cats with bronchial disease might be superior over monotherapy with prednisolone.

Evaluation of the clinical efficacy of pradofloxacin tablets for the treatment of canine pyoderma.

J Am Anim Hosp Assoc. 2010 Sep-Oct; 46(5): 301-11
Restrepo C, Ihrke PJ, White SD, Spiegel IB, Affolter VK

A third-generation fluoroquinolone, pradofloxacin (PRA), is currently being developed to treat bacterial infections in dogs. The purpose of this study was to assess the clinical efficacy in 20 dogs affected with superficial and deep pyoderma. An initial aerobic skin culture was performed in dogs with superficial pyoderma; aerobic/anaerobic tissue culture was performed in dogs with deep pyoderma; and skin cytology and biopsies were obtained from all dogs. Pradofloxacin (approximately 3 mg/kg per os [PO]) was administered daily to all dogs. Clinical efficacy was recorded at 4 weeks for dogs with superficial pyoderma and at 3 and 6 weeks for dogs with deep pyoderma. At a mean dosage of 3.7 mg/kg PO once daily, PRA treatment resulted in an excellent to good clinical response within 3 to 6 weeks for all 20 dogs with superficial and deep pyoderma.

The use of an acoustic device to identify the epidural space in cattle.

Vet J. 2010 Aug 30;
Iff I, Franz S, Mosing M, Lechner T, Moens YP

Twelve healthy cattle (weighing 188-835kg) were placed in stocks and sedated with xylazine. Caudal epidural puncture was performed using an acoustic device that indicated a decrease in resistance with a change in pitch. Lidocaine was injected to verify correct needle placement by assessing needle prick stimuli applied on the left and right side of the tail root and the perineal region, and the loss of tail and anal sphincter tone. Pressure measurements were recorded during penetration of the different tissue layers and in the epidural space. A clear and sudden decrease in the pitch of the acoustic signal was audible in all 12 cattle. All cows showed clinical effects indicating successful epidural anaesthesia. The pressure in the epidural space after puncture was -19+/-10mmHg. The device may be of assistance in identifying the epidural space in cattle.

Effect of Ergosan on semen quality of male rainbow trout (Oncorhynchus mykiss) broodstock.

Anim Reprod Sci. 2010 Aug 13;
Sheikhzadeh N, Reza A, Razi Allah JJ, Hossein TN

Present study was conducted to investigate the effect of Ergosan on seminal plasma compositions and spermatological parameters in rainbow trout. Male rainbow trout broodstocks (2300+/-200g) were fed diets containing Ergosan at 2 different concentrations (6mgkg(-1) and 20mgkg(-1)) and control diet without Ergosan for 20 days and on day 22 fish semen were sampled. Results suggest that Ergosan in dietary intake, significantly increased the spermatocrit and sperm count in 20mgkg(-1) group and Ca(2+) in both treatment groups compared to control group (P<0.05). The values of aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) had significant decrease in both treatment groups compared to the control group (P<0.05). Significant correlations were determined between sperm count versus K(+) value (r=-0.838, P<0.05) and glucose level (r=+0.835, P<0.05) in fish administrated with 20mgkg(-1) of Ergosan. In group treated with 6mgkg(-1), significant correlation between Na(+) and duration of sperm motility (r=+0.999, P<0.05) was shown. Meanwhile, glucose level versus percent of sperm motility (r=+0.866, P<0.05) showed significant correlation in this group. Sperm count versus total protein level (r=+0.817, P<0.05) showed significant correlation in control group. Results indicated that Ergosan had a potential efficacy on semen quality in rainbow trout broodstock.