Validation of a Combined In Vivo/In Vitro Ileal Fermentation Assay in the Growing Pig to be Used as a Model for Adult Humans.

BACKGROUND: An in vivo/in vitro ileal fermentation assay using growing pigs has been developed but not yet formally validated. OBJECTIVES: This study aimed to validate the in vivo/in vitro ileal fermentation assay by comparing in vitro fermentation values with those obtained in vivo in growing pigs. The effect of raising pigs under different environmental conditions was also investigated. METHODS: Thirty piglets (1.59 ± 0.31 kg body weight, mean ± standard deviation) were subjected to 1 of 3 treatments: artificially reared (AR) (nonfarm, laboratory housing conditions) from postnatal day (PND) 7 (AR group), inoculated orally with human infant fecal extracts from birth until PND 8 and AR (AR+ group), or conventionally reared on a farm (control group). Starting at PND 7, the AR and AR+ pigs received human infant formula for 3 wk, followed by a human-type diet for 5 wk. Control pigs were weaned on the farm and, on PND 63, relocated to the laboratory animal facility. From PND 63, all pigs received a human-type diet. On PND 78, pigs were killed, after which ileal digesta were collected to perform an in vitro ileal fermentation (in vitro organic matter [OM] fermentability and organic acid production) and to determine digesta microbial composition and dietary OM fermentability in vivo. RESULTS: The rearing regimen resulted in only a few differences in ileal microbial taxonomic composition. The rearing regimen generally did not affect the in vitro production of individual organic acids. The in vivo and in vitro OM fermentability of proximal ileal digesta (19.7 ± 2.04%; mean ± SEM) was similar (P > 0.05) for the AR and control pigs but not for the AR+ pigs. CONCLUSIONS: The control-rearing regimen was preferred over AR or AR+ because of ease of implementation. The in vitro ileal fermentation assay accurately predicted the in vivo OM fermentability.

A Systematic Review of Acute Irreducible Shoulder Dislocations in the 21st Century.

Background: Rarely, closed reduction cannot be achieved in patients with acute shoulder dislocation, necessitating open management. A paucity of literature exists regarding these cases. Purpose: To perform a systematic review on the mechanism, management, and outcome data of acute irreducible shoulder dislocations. Study Design: Systematic review; Level of evidence, 4. Methods: A systematic review of the literature was performed using the Cochrane Database of Systematic Reviews, the Cochrane Central Register of Controlled Trials, PubMed, and MEDLINE between 2000 and 2020. Inclusion criteria were as follows: human participants, acute irreducible shoulder dislocation requiring open management, English language, and publication within the past 20 years. We excluded basic science articles, technique articles, reviews, editorials, and studies of chronic shoulder dislocations or dislocations with ipsilateral humeral shaft fractures. Results: Twelve articles fit the inclusion criteria and were considered for review. All studies were single case reports (level 4 evidence). Ten of the 12 studies were of male patients. The direction of dislocation included 7 anterior/anteroinferior, 2 posterior, 1 inferior, 1 bilateral inferior, and 1 superolateral. Most dislocations were irreducible owing to a mechanical block to reduction. The most common type of block was an incarcerated long head of the biceps tendon, followed by interposition of 1 of the rotator cuff tendons. The axillary and musculocutaneous nerves, displaced fracture fragments, and Hill-Sachs and bony Bankart lesions were other causes of blocks to reduction. Eleven patients were treated with open surgery, while 1 patient was treated arthroscopically. Procedures performed were dependent on concurrent pathology. Final follow-up ranged from 6 weeks to 2 years, with no repeat dislocation episodes reported. Complications after open reduction included 1 case of brachial plexopathy (posterior cord) and 1 case of musculocutaneous nerve palsy. Conclusion: There is a paucity of literature on the management of irreducible acute shoulder dislocations. The most common irreducible dislocation found in this systematic review was anterior with a mechanical block attributed to interposition of the long head of the biceps tendon. When patients were treated with an open or arthroscopic procedure, recurrence was low, with none reporting recurrent dislocation in limited follow-up.

Safety of a live attenuated Erysipelothrix rhusiopathiae vaccine for swine.

Infection with Erysipelothrix rhusiopathiae has a significant economic impact on pig production systems worldwide. Both inactivated and attenuated vaccines are available to prevent development of clinical signs of swine erysipelas. The ability of a live attenuated E. rhusiopathiae strain to become persistently established in pigs after intranasal exposure and its potential to cause clinical signs consistent with swine erysipelas after being administered directly into the nasopharynx of healthy pigs was evaluated. Five, E. rhusiopathiae-negative pigs were vaccinated by deep intranasal inoculation then followed for 14 days. Nasal swabs were collected daily for 5 days and clinical observations were made daily for 14 days post-vaccination. Nasal swabs were cultured for E. rhusiopathiae with the intent of back-passaging any recovered organisms into subsequent replicates. No organism was recovered from nasal swabs in the first vaccination replicate. A second replicate including 10 pigs was initiated and followed in an identical manner to that described above. Again, no E. rhusiopathiae was recovered from any pigs. No pigs in either replicate showed any signs of clinical swine erysipelas. The live attenuated E. rhusiopathiae strain evaluated in this study did not appear to become persistently established in pigs post-vaccination, did not cause any local or systemic signs consistent with swine erysipelas, and was therefore unlikely to revert to a virulent state when used in a field setting.

Effect of blood sample handling post-collection on Erysipelothrix rhusiopathiae antibody titres.

A study was conducted to determine the effect of blood sample mishandling on the performance of an enzyme-linked immunosorbent assay for the detection of antibodies against Erysipelothrix rhusiopathiae. Eleven sample maltreatments (storage at -10 degrees C, storage at 4 degrees C, heat treatment of clotted blood, haemolysis, repetitive freeze-thaw cycling, and substitution of plasma in place of serum) were simulated in a laboratory environment and then run concurrently against a gold standard sample (storage at -80 degrees C). The mishandling treatment groups that simulated high levels of haemolysis had significantly lower optical density (OD) readings when compared to the gold standard. However, the magnitude of the effects was relatively small and only samples with OD values close to the cut-off changed state from positive to negative. Heat treatment had a minor, but non-significant, effect on OD values. Findings from this study suggested that immunoglobulin G antibody was stable in the face of most common sample mishandling events.

Assessment of the economic impact of porcine reproductive and respiratory syndrome on swine production in the United States.

OBJECTIVE: To estimate the annual cost of infections attributable to porcine reproductive and respiratory syndrome (PRRS) virus to US swine producers. DESIGN: Economic analysis. SAMPLE POPULATION: Data on the health and productivity of PRRS-affected and PRRS-unaffected breeding herds and growing-pig populations were collected from a convenience sample of swine farms in the midwestern United States. PROCEDURE: Health and productivity variables of PRRS-affected and PRRS-unaffected swine farms were analyzed to estimate the impact of PRRS on specific farms. National estimates of PRRS incidence were then used to determine the annual economic impact of PRRS on US swine producers. RESULTS: PRRS affected breeding herds and growing-pig populations as measured by a decrease in reproductive health, an increase in deaths, and reductions in the rate and efficiency of growth. Total annual economic impact of these effects on US swine producers was estimated at dollar 66.75 million in breeding herds and dollar 493.57 million in growing-pig populations. CONCLUSIONS AND CLINICAL RELEVANCE: PRRS imposes a substantial financial burden on US swine producers and causes approximately dollar 560.32 million in losses each year. By comparison, prior to eradication, annual losses attributable to classical swine fever (hog cholera) and pseudorabies were estimated at dollar 364.09 million and dollar 36.27 million, respectively (adjusted on the basis of year 2004 dollars). Current PRRS control strategies are not predictably successful; thus, PRRS-associated losses will continue into the future. Research to improve our understanding of ecologic and epidemiologic characteristics of the PRRS virus and technologic advances (vaccines and diagnostic tests) to prevent clinical effects are warranted.