The aim of this study was to determine the effect of feeding frequency and route of administration on abomasal luminal pH in suckling calves. Six male dairy calves with cannulae in the abomasal body were administered the following six treatments in a randomized crossover design: 24 h fasting, suckling of a high-quality milk replacer (all-milk protein; 12% of body weight [BW]/d) at 12-h (2x), 8-h (3x), 6-h (4x), and 3-h (8x) intervals, and ruminal intubation of milk replacer (12% of body weight/day) at a 12-h (2x) interval. Abomasal luminal pH was measured every second for 24 h with miniature glass pH electrodes. Least squares mean 24-h fasting abomasal luminal pH was 1.73, whereas mean 24-h pH after suckling and intubation of milk replacer every 12 h were higher at 3.44 and 3.17, respectively. Increasing the frequency of milk replacer suckling to 3x, 4x, and 8x increased mean 24-h abomasal luminal pH; however, there was no difference in mean 24-h pH between 3x (3.69), 4x (3.64), and 8x (3.67) suckling. The percentage of the 24-h recording period that abomasal luminal pH was > 3.0 was 0, 49, 53, 61, 61, and 71% for fasting, 2x intubation of milk replacer, and 2x, 3x, 4x, and 8x suckling of milk replacer, respectively. Increasing the frequency of milk replacer suckling may be efficacious in the prophylaxis of abomasal ulceration in milk-fed calves.

The aim of this study was to investigate a cell delivery system for repair of severe chronic osteochondral defects using magnetically labeled mesenchymal stem cells (m-MSCs), with the aid of an external magnetic device, through the accumulation of a small number of m-MSCs into a desired area and to detect the suitable number of autologous m-MSCs needed for repair of the defect. Twenty-six male Japanese white rabbits aged 6 months were used. An osteochondral defect was created bilaterally at the weight-bearing surface of the medial femoral condyle of the rabbits' knees (3 mm diameter; 4 mm depth). At 4 weeks after creation of the defect, autogenic transplantation of the m-MSCs into the defect area was performed, followed by 10-min exposure to an external magnetic device, where animals were divided into four groups: high (1 × 10 6 m-MSCs), medium (2 × 10 5 m-MSCs), low (4 × 10 4 m-MSCs), and control (PBS injection). At 4 and 12 weeks posttransplantation of m-MSCs, repaired tissue was assessed histologically using the Fortier score with toluidine blue staining. Transplantation of a low number of m-MSCs was not enough to improve osteogenesis and chondrogenesis, but the medium and high groups improved repair of the chronic defect with chondrogenic tissues and showed histologically significantly better results than the control and low groups. The use of a magnetic targeting system for delivering m-MSCs has the potential to overcome the clinical hurdles for repair of the severe chronic osteochondral defect. Furthermore, this system is predicted to produce good clinical outcomes for humans, not only to repair osteochondral defects but also to repair a variety of damaged tissues.

No abstract

Abomasal acid secretion in milk-fed calves is mediated in part by histamine type-2 receptors. Cimetidine and ranitidine may be efficacious in the treatment of abomasal ulcers in milk-fed calves.

Mesenchymal stem cells (MSCs) have been demonstrated to be useful for cartilage tissue regeneration. Bone marrow (BM) and synovial fluid (SF) are promising sources for MSCs to be used in cartilage regeneration. In order to improve the clinical outcomes, it is recommended that prior to clinical use, the cellular properties and, specifically, their chondrogenic potential must be investigated. The purpose of this study is to compare and better understand the in vitro chondrogenic potential of equine bone marrow-derived mesenchymal stem cells (BMMSCs) and synovial fluid-derived mesenchymal stem cells (SFMSCs) populated from the same equine donor. BM- and SF-derived MSCs cultures were generated from five equine donors, and the MSCs were evaluated in vitro for their morphology, proliferation, trilineage differentiation, and immunophenotyping. Differences in their chondrogenic potentials were further evaluated quantitatively using glycosaminoglycan (GAG) content and via immunofluorescence of chondrogenic differentiation protein markers, SRY-type HMG box9, Aggrecan, and collagen II. The BMMSCs and SFMSCs were similar in cellular morphology, viability, and immunophenotype, but, varied in their chondrogenic potential, and expression of the key chondrogenic proteins. The SFMSCs exhibited a significant increase in GAG content compared to the BMMSCs (P < 0.0001) in three donors, suggesting increased levels of chondrogenesis. The expression of the key chondrogenic proteins correlated positively with the GAG content, suggesting that the differentiation process is dependent on the expression of the target proteins in these three donors. Our findings suggest that even though SFMSCs were hypothesized to be more chondrogenic relative to BMMSCs, there was considerable donor-to-donor variation in the primary cultures of MSCs which can significantly affect their downstream application.

Abomasal ulceration occurs commonly in suckling calves, and the cause for the high prevalence of abomasal ulceration is unknown. We hypothesized that diet may play a role in the etiopathogenesis of abomasal ulceration. Six male dairy calves with an abomasal body cannula suckled fresh Holstein cow's milk, all milk-protein milk replacer, or combined milk- and soy-protein milk replacer twice daily at 12% of body weight/d. Abomasal luminal pH was measured every second for 24 hours by using a miniature glass pH electrode. Mean 24-hour abomasal luminal pH for all milk-protein milk replacer (3.22) and combined milk- and soy-protein milk replacer (3.27) were similar but significantly (P < .05) higher than that for cow's milk (2.77; standard error = 0.08). Both milk-replacer formulations failed to clot after the addition of chymosin, whereas cow's milk clotted within 2 minutes. The in vitro titration curve of cow's milk and all milk-protein milk replacer were similar, but different to that of combined milk- and soy-protein milk replacer. The osmolalities of all milk-protein milk replacer (375 mOsm/kg) and combined milk- and soy-protein milk replacer (410 mOsm/kg) were greater than that of cow's milk (278 mOsm/kg). The slightly lower mean abomasal luminal pH in calves suckling cow's milk, compared to milk replacer, was probably due to clotting of cow's milk, with extrusion of low pH whey, and a slower rate of abomasal emptying caused by the hyperosmolality of milk replacer. Examination of our results suggests that suckling cow's milk may increase the prevalence of abomasal ulceration by decreasing mean luminal pH, although this remains to be determined.

Survey radiography is used in diagnosis of different affections in buffaloes and cattle. The aim of the present study was to assess the role of radiography in diagnosis of reticular diaphragmatic hernias and traumatic pericarditis in buffaloes and cattle. The present study was carried out on 69 animals (51 buffaloes and 18 cattle). Reticular diaphragmatic hernias (40 buffaloes, 4 cattle) and traumatic pericarditis (11 buffaloes, 14 cattle) were evaluated. Lateral right-left survey radiography of the thorax was performed. In diaphragmatic hernia, radiography revealed presence of a rounded or vertical oval mass of soft tissue opacity superimposed over the heart. Radiopaque foreign bodies of variable shape and size were seen within the herniated part of the reticulum. The apex of the heart was difficult to visualize. With traumatic pericarditis, survey radiography of the thorax revealed poor differentiation of thoracic contents. The contour of the diaphragm was lost and the cardiac silhouette was obscured. In several animals radiopaque foreign bodies (sewing needles, nails, and pieces of wire) were detected at the level of the heart or in the area connecting the dome of the diaphragm with the heart.

Horses are widely used as large animal preclinical models for cartilage repair studies, and hence, there is an interest in using equine synovial fluid-derived mesenchymal stem cells (SFMSCs) in research and clinical applications. Since, we have previously reported that similar to bone marrow-derived MSCs (BMMSCs), SFMSCs may also exhibit donor-to-donor variations in their stem cell properties; the current study was carried out as a proof-of-concept study, to compare the in vivo potential of equine BMMSCs and SFMSCs in articular cartilage repair. MSCs from these two sources were isolated from the same equine donor. In vitro analyses confirmed a significant increase in COMP expression in SFMSCs at day 14. The cells were then encapsulated in neutral agarose scaffold constructs and were implanted into two mm diameter full-thickness articular cartilage defect in trochlear grooves of the rat femur. MSCs were fluorescently labeled, and one week after treatment, the knee joints were evaluated for the presence of MSCs to the injured site and at 12 weeks were evaluated macroscopically, histologically, and then by immunofluorescence for healing of the defect. The macroscopic and histological evaluations showed better healing of the articular cartilage in the MSCs' treated knee than in the control. Interestingly, SFMSC-treated knees showed a significantly higher Col II expression, suggesting the presence of hyaline cartilage in the healed defect. Data suggests that equine SFMSCs may be a viable option for treating osteochondral defects; however, their stem cell properties require prior testing before application.