Influence of tibial plateau leveling osteotomy and tibial tuberosity advancement on passive laxity of the cranial cruciate deficient stifle in dogs.

OBJECTIVE: To evaluate the effect of tibial plateau leveling osteotomy (TPLO) and tibial tuberosity transposition (TTA) on craniocaudal stability of the cranial cruciate ligament (CCL) deficient stifle at 3 joint angles. STUDY DESIGN: Ex vivo biomechanical study. SAMPLE POPULATION: Eight stifles from 4 dogs. METHODS: One of the hind limbs was randomly assigned to undergo TPLO or TTA, with the contralateral limb assigned to the alternate procedure. Each specimen was tested with the stifle at 150°, 135°, and 120° of flexion. Cranial translation of the tibia relative to the femur was measured under cranial loads ranging from 0.2 to 2.0 kg with a single motion tracking sensor (Nest of Birds) fixed to the tibia. Each stifle was tested before and after transection of the CCL and after performing the assigned procedure. RESULTS: Tibial plateau leveling osteotomy and TTA caused a decrease in the cranial translation of the tibia relative to the femur, especially at greater angles of flexion. Tibial plateau leveling osteotomy caused a greater decrease in tibial cranial translation and was associated with a degree of translation that did not differ from joints with intact CCL, regardless of the degree of stifle flexion. CONCLUSION: Tibial plateau leveling osteotomy and TTA caused an angle dependent decrease in craniocaudal translation of the tibia in the CCL deficient stifle. Only TPLO restored translations similar to those of the intact joint at all angles tested. CLINICAL IMPACT: Tibial plateau leveling osteotomy and TTA provide passive stability to the stifle. Tibial plateau leveling osteotomy seems more effective than TTA at restoring craniocaudal stability of the stifle.

Galaxy rotation curves via conformal factors.

We propose a new formula to explain circular velocity profiles of spiral galaxies obtained from the Starobinsky model in the Palatini formalism. It is based on the assumption that the gravity can be described by two conformally related metrics: one of them is responsible for the measurement of distances, while the other, the so-called dark metric, is responsible for a geodesic equation and therefore can be used for the description of the velocity profile. The formula is tested against a subset of galaxies taken from the HI Nearby Galaxy Survey (THINGS).

Florfenicol feed supplemented decrease the clinical effects of Mycoplasma hyopneumoniae experimental infection in swine in México.

The therapeutic value of Florfenicol feed supplemented was evaluated in conventional pigs to eliminate consequences of chronic infection of Mycoplasma hyopneumoniae. The experimental animals were pigs with an average of 16 kg, after intratracheally inoculation with M. hyopneumoniae they were divided in two experimental groups: (a) the non-medicated; and (b) the feed supplemented group (20 g Florfenicol/ton of feed) during the ensuing 35 days. The average daily weight gain of the Florfenicol-treated pigs (0.33±0.14 kg/day) was significantly higher than that of the non-treated ones (0.21±0.10 kg/day). In medicated animals was still impaired relative to that of the uninfected ones control group (0.39±0.02 kg/day). The average percentage of pneumonic gross lesions extensions' of the pigs groups was: 13.99% for M. hyopneumoniae infected non-medicated group; 1.79% M. hyopneumoniae infected, Florfenicol-treated group and, 0.56% of the uninfected control group. M. hyopneumoniae; colonization was detected at these levels in 7 and 9 members of the respective infected groups. The extent of the pneumonic lesions and M. hyopneumoniae generally was greater in the non-medicated pigs. Therefore, oral administration of Florfenicol via feed ingestion seemed to be somewhat effective in ameliorating the clinical effects of M. hyopneumoniae infection of swine.

Optimised nuclear medicine method for tumour marking and sentinel node detection in occult primary breast lesions.

The aim of this study was to evaluate the feasibility of sentinel node (SN) biopsy in occult breast lesions with different radiopharmaceuticals and to establish the optimal lymphoscintigraphic method to detect both occult lesions and SNs (SNOLL: sentinel node and occult lesion localisation). Two hundred and twenty-seven consecutive patients suspected to have clinically occult breast carcinoma were enrolled in the study. In addition to the radioguided occult lesion localisation (ROLL) procedure, using macroaggregates of technetium-99m labelled human serum albumin (MAA) injected directly into the lesion, lymphoscintigraphy was performed with nanocolloids (NC) injected in a peritumoral (group I) or a subdermal site (group II). In group III, a sole injection of NC was done into the lesion in order to perform both ROLL and SNOLL. Overall, axillary SNs were identified in 205 of the 227 patients (90.3%). In 12/62 (19.4%) patients of group I and 9/79 (11.4%) patients of group III, radioactive nodes were not visualised, whereas SNs were successfully localised in 85 of 86 patients of group II ( P<0.001). Pathological findings revealed breast carcinoma in 148/227 patients (65.2%) and benign lesions in 79 (34.8%). A total of 131 axillary SNs were removed in 118 patients with breast carcinoma; intraoperative examination of the SNs revealed metastatic involvement in 16 out of 96 cases of invasive carcinoma (16.7%). It is concluded that the combination of the ROLL procedure with direct injection of MAA into the lesion and lymphoscintigraphy performed with subdermal injection of radiocolloids represents the method of choice for accurate localisation of both non-palpable lesions and SNs.

The effect of vaccination with the PAV-250 strain classical swine fever (CSF) virus on the airborne transmission of CSF virus.

The airborne transmission of Classical Swine Fever (CSF) virus to susceptible pigs, as well as the effect of vaccination with the CSF virus PAV-250 strain was investigated on this mode of transmission. Experiment I: four pigs were inoculated with the ALD CSFV strain (10(4.3) 50% TCID) by the intramuscular route, and at the onset of fever, they were introduced into an enclosed chamber. At the end of the experiment surviving pigs were sedated, anesthetized and euthanatized. Experiment II: four pigs were previously vaccinated with the CSF virus PAV-250 strain, and at 14 days post-vaccination they were challenged with the CSF virus ALD strain. In both experiments, four susceptible pigs were exposed to infectious aerosols by placing them in a chamber connected by a duct to the adjacent pen containing the infected animals and were kept there for 86 hs. In Experiment I, pigs exposed to contaminated air died as a result of infection with CSF virus on days 14, 21 and 28 post-inhalation. These four pigs seroconverted from day 12 post-inhalation. CSF virus was isolated from these animals, and the fluorescent antibody test on tonsils was positive. In Experiment II, a vaccinated pig exposed to contaminated air did not seroconvert, nor was CSF virus isolated from lymphoid tissues. However, mild fluorescence in tonsil sections from these pigs was observed. In conclusion, CSF virus was shown to be transmitted by air at a distance of 1 m to susceptible pigs. Vaccination with the PAV-250 CSF virus strain protected the pigs from clinical disease under the same conditions.

Immunomodulatory properties of Mycoplasma pulmonis. I. Characterization of the immunomodulatory activity.

For many years, it has been recognized that Mycoplasma infection affects the host's immune system in different ways. In this work, experiments were performed to characterize the influence of Mycoplasma pulmonis infection on various immunological parameters and to follow the kinetics of their variations. A Balb/c mouse model was used to assess hematological evaluations, changes in spleen weight, antibody responses against sheep erythrocytes, neutrophil phagocytosis, colloidal carbon clearance, and anti-Mycoplasma antibody responses. At the hematological level, infected animals were found to have significantly increased total lymphocyte and polymorphonuclear leukocyte counts and an augmentation in spleen weight. Seven days after Mycoplasma infection, antibody responses against sheep erythrocytes were considerably diminished, and at days 7 and 14 after infection, phagocytic activity was also reduced. After 1 week of infection, the colloidal carbon clearance pattern was decreased, and during the whole infectious process, anti-Mycoplasma antibody titers were found to be low. Results from this part of research show a persistent infection that does not resolve in a short period, which is associated with a general dysfunction in the immune system and poor immune responses against several different antigens.

Mycoplasma hyopneumoniae: interaction with other agents in pigs, and evaluation of immunogens.

Mycoplasmal pneumonia of swine causes considerable economic losses in porciculture. Diverse agents, such as environmental stress and infectious microorganisms, increase the possibility of infection, and the damage to pulmonary tissue when the infection is established. It is known that Mycoplasma hyopneumoniae has an important role in this disease, in addition to secondary microbial agents, such as Pasteurella multocida and Actinobacillus pleuropneumoniae. However, the characteristics of this disease in farms are well known. In this work we review the interactions among the different microorganisms involved and the immunological strategies utilized to control this disease. The interaction between Mycoplasma hyopneumoniae and P. multocida in experimental pneumonia was reported by us in conventional pigs. M. hyopneumoniae causes mild pneumonia, whereas P. multocida aggravates the pneumonia initiated by M. hyopneumoniae. The disease has been reproduced to test the efficacy of two immunogens, and can also be used to evaluate some antibiotics. A M. hyopneumoniae bacterine administered intraperitoneally conferred more protection than when it was used with adjuvant, although protection was not complete and colonization by M. hyopneumoniae was not prevented, as is claimed to have been the case with other vaccines.

Comparison of three biological assays for the detection of toxigenic properties of Bordetella bronchiseptica associated with atrophic rhinitis.

The toxigenic properties of Bordetella bronchiseptica strains associated with clinical atrophic rhinitis were compared using three biological assays: the guinea pig skin test, the mouse spleen atrophy and the suckling mice mortality assay. Forty one sick pigs were cultured and, in 20 of them B. bronchiseptica strains were isolated. Eighteen of the strains were toxigenic by at least one test. However, positivity did not always coincide amongst assays. This discrepancy raises the possibility of either differences in sensitivity between assays or the existence of more than one toxin.

Mycoplasma hyopneumoniae increases the susceptibility of pigs to experimental Pasteurella multocida pneumonia.

The interaction between Mycoplasma hyopneumoniae and Pasteurella multocida in experimental pneumonia was investigated in conventional pigs. The experimental animals were 49 days old when inoculated with M. hyopneumoniae; they were inoculated with P. multocida after 23 days, and killed 13 days later. In pigs inoculated only with P. multocida, clinical signs and lung lesions were not observed, and the agent was not recovered. Pigs inoculated with M. hyopneumoniae developed fever, moderate cough and dyspnea which tended to disappear, and small proliferative lung lesions from which M. hyopneumoniae was isolated. Pigs inoculated with both agents had higher fever, severe cough and dyspnea which tended to aggravate, and extensive exudative lung lesions from which organisms were isolated. All animals had similar growth rates, but the group infected with both agents consumed 60% more food. Therefore, M. hyopneumoniae causes mild pneumonia, whereas P. multocida is not pathogenic alone but aggravates the pneumonia initiated by M. hyopneumoniae.