Evaluation of slice shear force as an objective method of assessing beef longissimus tenderness.

Experiments were conducted to develop an optimal protocol for measurement of slice shear force (SSF) and to evaluate SSF as an objective method of assessing beef longissimus tenderness. Whereas six cylindrical, 1.27-cm-diameter cores are typically removed from each steak for Warner-Bratzler shear force (WBSF) determination, a single 1-cm-thick, 5-cm-long slice is removed from the lateral end of each longissimus steak for SSF. For either technique, samples are removed parallel to the muscle fiber orientation and sheared across the fibers. Whereas WBSF uses a V-shaped blade, SSF uses a flat blade with the same thickness (1.016 mm) and degree of bevel (half-round) on the shearing edge. In Exp. 1, longissimus steaks were acquired from 60 beef carcasses to determine the effects of belt grill cooking rate (very rapid vs. rapid) and conditions of SSF measurement (hot vs cold) on the relationship of SSF with trained sensory panel (TSP) tenderness rating. Slice shear force was more strongly correlated with TSP tenderness rating when SSF measurement was conducted immediately after cooking (r = -.74 to -.76) than when steaks were chilled (24 h, 4 degrees C) before SSF measurement (r = -.57 to -.72). When SSF measurement was conducted immediately after cooking, the relationship of SSF with TSP tenderness rating did not differ among the belt grill cooking protocols used to cook the SSF steak. In Exp. 2, longissimus steaks were acquired from 479 beef carcasses to compare the ability of SSF and WBSF of 1.27-cm-diameter cores to predict TSP tenderness ratings. Slice shear force was more strongly correlated with sensory panel tenderness rating than was WBSF (r = -.82 vs -.77). In Exp. 3, longissimus steaks were acquired from 110 beef carcasses to evaluate the repeatability (.91) of SSF over a broad range of tenderness. Slice shear force is a more rapid, more accurate, and technically less difficult technique than WBSF. Use of the SSF technique could facilitate the collection of more accurate data and should allow the detection of treatment differences with reduced numbers of observations and reduced time requirements, thereby reducing research costs.     

Aetiology and diagnosis of persistent nasal disease in the dog: a retrospective study of 42 cases

Forty-two dogs with a history of persistent nasal disease were evaluated by a combination of clinical examination, thoracic and nasal radiography, retroflexed endoscopy and biopsy, and anterograde rhinoscopy and blind nasal biopsy. A definitive diagnosis was made in 91 per cent of cases. Neoplasia was the most common diagnosis (33 per cent of cases), followed by inflammatory rhinitis (24 per cent). Other diagnoses included periodontal disease (10 per cent), aspergillosis (7 per cent) and foreign bodies (7 per cent). Adenocarcinoma was the most common tumour diagnosed. The clinical findings were found to be too variable to be used as specific diagnostic criteria. Anterograde rhinoscopy and retroflexed endoscopy had higher specificity and sensitivity than radiology for the diagnosis of neoplasia, inflammatory rhinitis, aspergillosis and foreign bodies. With a systematic approach to the investigation of persistent nasal disease, a definitive diagnosis can be successfully obtained in the vast majority of cases.     

DNA polymorphism of srRNA gene among Eimeria tenella strains isolated in Japan

DNA polymorphism in twelve starains of Eimeria tenella isolated from various places in Japan was examined using 1.l kb small subunits ribosomal RNA amplified by PCR. Genetic variation was evaluated by random amplification of polymorphic DNA (RAPD) analysis. DNA fingerprint patterns were grouped into two, indicating that at least two DNA polymorphisms exist in Japanese E. tenella strains.     

Usefulness of aerobic microbial culture and cytologic evaluation of corneal specimens in the diagnosis of infectious ulcerative keratitis in animals

OBJECTIVE: To determine the diagnostic value of aerobic microbial culture and cytologic evaluation of corneal specimens in the diagnosis of infectious ulcerative keratitis (IUK). DESIGN: Prospective study. ANIMALS: 48 animals (26 dogs, 13 horses, 7 cats, 1 bird, and 1 llama) with corneal ulcers. PROCEDURE: Scrapings from corneal ulcers were examined cytologically. Corneal swab specimens were submitted for microbial culture. Animals were grouped according to whether they had been receiving antimicrobials at the time of admission. RESULTS: Of the 38 animals receiving antimicrobials, 19 had positive results for IUK on cytologic evaluation, 20 on microbial culture, and 26 on cytologic evaluation, microbial culture, or both. Of the 10 animals not receiving antimicrobials at the time of admission, 7 had positive results for IUK on cytologic evaluation, and 9 had positive results on microbial culture. In this group of 10 animals, additional animals with IUK were not identified on the basis of cytologic evaluation alone. When all 48 animals were considered irrespective of antimicrobial treatment, 26 and 29 had positive results for IUK on cytologic evaluation and microbial culture, respectively, whereas IUK was confirmed in 35 animals on the basis of cytologic evaluation, microbial culture results, or both. CONCLUSIONS AND CLINICAL RELEVANCE: Microbial culture and cytologic evaluation of corneal specimens maximizes identification of IUK, especially in animals receiving antimicrobial treatment. Because of serious consequences of untreated IUK, we recommend that both diagnostic tests be used to tailor treatment and reduce risk of vision impairment in animals.     

Matrix metalloproteinase-2 and -9 are activated in joint diseases.

A study was performed to identify the activation status of the gelatinase MMPs, MMP-2 and -9, in both normal and diseased equine articular tissues. In addition, the production and activation status of equine MMP-2 and -9 by equine articular cells and tissues in response to increasing IL-1beta concentrations was assessed. The study was performed to test the hypothesis that activation of MMPs is a fundamental step in the pathogenesis of joint diseases; and that this activation is mediated by the cytokine IL-1. Using purified equine MMP-2 and -9, the molecular weights of the zymogen and activated form of equine MMP-2 and -9 were identified by a combination of gelatin zymography and a gelatin degradation assay using aminophenylmercuric acetate as a chemical activator of the molecules. Normal equine articular tissues (cartilage and synovial membrane) maintained in short-term tissue culture produced MMP-2 zymogen alone, while similar tissues obtained from a variety of pathological conditions produce both zymogen and active MMP-2, as well as MMP-9 monomer and dimer. Activated MMP-9 was an inconsistent finding. Normal equine synovial fibroblasts in monolayer culture produced zymogen MMP-2 alone under basal conditions. A mild increase in active and zymogen MMP-2 levels occurred with IL-1beta treatment. Equine synovial membrane explants demonstrated a dose-dependent increase in active and zymogen MMP-2 and MMP-9 levels following IL-1beta treatment. Monolayer chondrocyte cell cultures demonstrated a dose-dependent mild increase in active and zymogen MMP-2 following IL-1beta treatment. Explant cartilage cultures demonstrated a dose-dependent mild increase in zymogen MMP-2 alone following IL-1beta treatment. This study supports the hypothesis that activation of MMPs is occurring in joint disease, and that in vitro stimulation of equine articular cells and tissues causes not only an increase in MMP production, but also an increase in amount of activated enzyme released. Further research is required to investigate the role of MMP activation in joint diseases, and to investigate the potential use of therapeutic agents, which inhibit MMP activation, in the treatment and prevention of joint diseases.     

Hemorrhagic septicemia in fallow deer (Dama dama) caused by Pasteurella multocida multocida.

Four outbreaks of hemorrhagic septicemia caused by Pasteurella multocida multocida occurred in a population of 1,800 fallow deer (Dama dama) during 1992-1996. A total of 340 fallow deer were submitted for postmortem examination. Pasteurellosis was diagnosed in 273 of 312 deer suspected of having septicemia. Pasteurella multocida was isolated from 257 animals, and the diagnosis was based on typical pathologic changes alone in the other 16 animals. Pasteurella multocida was isolated in pure culture from 219 of 248 samples of cerebrospinal fluid. Eighteen animals were observed moribund with severe depression, foamy nasal discharge, and respiratory distress, and 257 were found dead. Major clinical signs and pathologic changes included extensive swelling of the head and the neck and peracute or acute septic pneumonia, petechial and ecchymotic hemorrhages on serous membranes, and severely hemorrhagic adrenal glands and abomasum. Rhinitis and necrotic pharyngeal mucosae were common. Histologically, the most advanced lesions were in the nasal mucosa and pharynx. The swelling of the head and the neck arose from a diffuse cellulitis in the subcutaneous and intermuscular tissues. The earliest lesions in the lungs included large numbers of bacteria in the pulmonary capillaries, but various degrees of fibrinous exudation to the alveoli and infiltration with heterophils usually were observed.     

Failure of viral protein 3 of infectious bursal disease virus produced in prokaryotic and eukaryotic expression systems to protect chickens against the disease

In recent years, infectious bursal disease virus (IBDV) has become a serious economic problem as a result of the emergence of new and very virulent strains. Most of the antibodies produced against IBDV are for the structural proteins viral protein (VP) 2 (VP2) and VP3. The purpose of this study was to test the potential of recombinant VP3 to induce protective antibodies. The gene for VP3 was isolated from a virulent strain of the virus and cloned into prokaryotic (Escherichia coli) and eukaryotic (baculovirus) expression systems. The protein expressed by both systems was of the expected size (32 kD) and was detected by anti-IBDV antibodies. Following partial purification, the polypeptides were injected into intact birds and induced the production of high levels of anti-IBDV antibodies, as detected by immunoblot and enzyme-linked immunosorbent assay tests. These antibodies did not prevent changes in the bursa and mortality when birds were challenged with a virulent IBDV strain after vaccination with the recombinant VP3. The results show that VP3 polypeptide cannot be used as a subunit vaccine against IBDV and raise questions concerning the nature of the neutralizing epitope on this structural protein.     

Surgical management of bifid sternum in two African grey parrots

Transposition of the pectoral muscles for treatment of caudal bifid (cleft) sternum in 2 unrelated African Grey Parrots is described. The birds did not have clinical signs of ventilatory compromise prior to surgery; however, both had cutaneous ulcers over the defects. The pectoral muscles provided a thick pad over the heart, minimizing the risk of trauma to the heart.