The Influence of Parenterally Administered α‐Tocopheryl Acetate to Sows on the Vitamin E Status of the Sows and Suckling Piglets and Piglets After Weaning

The main aim of the study was to test if parenteral administration of α‐tocopheryl acetate twice before farrowing and weaning could increase the vitamin E status of the newborn piglets and piglets after weaning. In Trial I eight sows were given 1.5 g α‐tocopheryl acetate intramuscularly 7 and 2 days before farrowing. Eight sows were untreated controls. The experimental sows had a higher vitamin E concentration in colostrum than the controls. No significant difference between the groups existed in milk at weaning. The serum vitamin E concentration in the experimental piglets 2 and 5 days after farrowing was higher than in the controls. Fifteen days after farrowing the difference between the groups had nearly disappeared. The serum vitamin E concentration in the piglets in the control group was higher during the first days after farrowing than later, and was gradually reduced until at least 2 weeks after weaning. In Trial II, eight sows were given 1.5 g of α‐tocopheryl acetate 7 and 2 days before weaning of their piglets. They had higher vitamin E concentrations in milk and serum than untreated control sows at weaning. The increase did not, however, influence the serum vitamin E concentration of the piglets. The lowest concentration of vitamin E in serum of the piglets was reached at 45 days after farrowing. The activity of the selenium‐dependent enzyme glutathione peroxidase in the serum of piglets was very low during the first week of life in both groups despite the fact that the sows’ feed had been supplemented with 0.35 mg selenium/kg. This indicates that the selenium status of newborn piglets might be more critical for their health than their vitamin E status.     

Oxytocin‐induced PGF2α Release in Mares With and Without Post‐breeding Delayed Uterine Clearance

The aim of the present study was to evaluate within 24 h post‐ovulation oxytocin‐induced PGF_2α release in mares with and without post‐breeding delayed uterine clearance (DUC). Twenty‐one of 34 mares with a variable amount of intrauterine fluids accumulation were considered to be affected by delayed uterine clearance (DUC group), while the other 13 mares did not show any uterine fluid accumulation, and were considered as controls (WDUC group). Both DUC and WDUC mares were administered with 20 IU oxytocin i.m. 90 min after the ultrasound examination performed 24 h after breeding. Immediately before, 5 and 10 min after oxytocin administration, blood samples were collected for 15‐ketodihydro‐PGF_2α (PG‐metabolite), 17β‐estradiol, and progesterone analysis. Ultrasonography performed 24 h after oxytocin treatment showed a complete uterine clearance in all DUC mares. The oxytocin‐induced PG‐metabolite increase was detected in 71.4% DUC mares compared with 38.5% in WDUC group, with a positive trend of release, as evidenced from 5 min after oxytocin administration. In WDUC mares, no significant differences in oxytocin‐induced PG‐metabolite trend of release were observed. In conclusion, the results of the present study showed the importance of PGF_2α involvement in the pathogenesis of post‐breeding DUC in the mare.     

Adhesion molecules α, β and γ‐catenin as prognostic factors of tumour progression in upper urinary tract urothelial tumours: the role of AKT‐P/GSK‐3β/β‐catenin pathway

OBJECTIVES

To evaluate α, β and γ‐catenin expression in upper urinary tract urothelial tumours (UUTC) and determine their value as prognostic factors; to investigate the correlation between the catenin complex and the AKT pathway.

PATIENTS AND METHODS

We retrospectively analysed 114 consecutive patients treated at our institution from 1990 to 2004; the mean follow‐up was 54 months. Tumour samples were available from 70 patients, and included in tissue microarrays for immunohistochemical analysis. The antibodies used were anti‐α, ‐β and γ‐catenin, and antiphospho‐AKT. The prognostic value of the expression of these molecules was analysed using tumour progression and cancer‐specific survival as end‐points.

RESULTS

Of the 114 patients, 27% developed tumour progression; the cancer‐specific and overall survival were 77% and 60.6%, respectively. Abnormal α, β and γ‐catenin expression was found in 44 (63%), 22 (31%) and 28 (41%) patients, respectively; the abnormal catenin expression patterns correlated with each other. Positive cytoplasm phospho‐AKT expression was found in 27 (39%) patients. Three of them were found to have cytoplasmic β‐catenin accumulation and none of them nuclear expression. β‐catenin expression was the only one that was an independent marker of tumour progression, with a hazard ratio (95% confidence interval) of 3.1(1.2–8.6), together with grade (7.1, 1.2–55.8) and stage (4.6, 2.1–10). In the cancer‐specific survival analysis, again β‐catenin was an independent prognostic factor (3.4, 1–11.5) together with stage (4.6, 2.2–9.8).

CONCLUSIONS

The loss of the normal membrane β‐catenin expression constitutes an independent factor of tumour progression and cancer‐specific survival. Our data suggest that the AKT/GSK3β/β‐catenin signalling pathway is not activated in the UUTC carcinogenesis.     

Plasma Concentrations of 15‐Ketodihydro‐PGF2α, Cortisol and Progesterone during Manual Twin Reduction in Thoroughbred Mares

The aim of the present study was to highlight the effect of two different techniques of one embryo crushing on some hormonal changes. Ten twinning mares were submitted to the mobile or fixed manual crushing of one blastocyst within day 19 after the last mating. Blood sample was collected from 20 min before to 90 min, 24 and 72 h after the procedure was performed to analyse 15‐ketodihydro‐PGF_2α, cortisol and progesterone plasma concentrations. Singleton pregnancy diagnosis was checked 72 h after crushing and at term of pregnancy. Because the unwanted crushing of both embryos occurred in one mare during the attempt of manual separation of the twins, that mare was not included in the evaluation of crushing‐induced hormonal changes. No significant differences in hormonal concentrations were observed after one embryo crushing and also when the effect of the mobile (n = 6) or fixed (n = 3) technique was specifically evaluated. When the effect of the two techniques on each post‐crushing sampling time hormonal levels was analysed, only a higher cortisol level 30 min after the fixed compared with the mobile technique was observed. The crushing performed within 19 days of gestation does not induce significant changes in 15‐ketodihydro‐PGF_2α, cortisol or progesterone plasma concentrations. When the fixed technique was performed, only a temporary higher cortisol concentration was seen 30 min after crushing, suggesting that the fixed technique might be responsible for a slight level of stress for the mare.     

Biochemical changes in malignant hyperthermia susceptible swine: cyclic AMP,inositol phosphates, α1, β1- and β2-adrenoceptors in skeletal and cardiac muscle

It has been presumed that alteration in the concentrations of second messengers leads to alterations in the function of the ryanodine receptor. Consequently, we have determined the basal content of cyclic AMP and inositol phosphates in skeletal and cardiac muscle of malignant hyperthermia (MH) susceptible (MHS) and healthy normal control (MHN) swine. Since α,- and β-adrenoceptors are linked to these second messenger systems, the densities of α₁,- and β-adrenoceptors were also determined. In skeletal as well as cardiac muscle, a higher basal concentration of almost all of the inositol phosphates was found. Of all inositol phosphates measured, the presumed second messenger inositol 1,4,5-trisphosphate (1,4,5-IP3) was mostly concentrated in both tissues. Each MHS sample contained more 1,4,5,-IP3 than the highest value observed in MHN muscle, indicating that a threshold of 1,4,5-IP3 concentration for determination of MHS or MHN status can be defined. In addition, MHS skeletal muscle contained more cAMP than MHN, whereas there was no difference between MHS and MHN in cardiac muscle. The changes observed in the different inositol phosphate and cAMP contents were not accompanied by an altered α₁,- or β-adrenoceptor density in skeletal or cardiac muscle between MHS and MHN. However, the total number of β-adrenoceptors of MHN and MHS was significantly higher in cardiac (about 80 fmol/mg protein) than skeletal muscles (about 30 fmol/ mg protein). The cardiac muscles revealed about 80% β₁,- and 20% β₂-adrenoceptors, whereas skeletal muscles were characterised by over 95% β₂-adrenoceptors. In conclusion, the present study supports the view that altered second messenger systems and, thereby, altered intracellular calcium regulations are at least in part involved in the modulation and development of MH. Moreover, in addition to the skeletal muscle, multiple other organs, e.g. heart, may be affected in MH.     

Modulation of wound contracture α‐smooth muscle actin and multispecific vitronectin receptor integrin αvβ3 in the rabbit's experimental model

The myofibroblast, a major component of granulation tissue, is a key cell during wound healing, tissue repair and connective tissue remodelling. Persistence of myofibroblasts within a fibrotic lesion leads to excessive scarring impairing function and aesthetics. Various wound‐healing cytokines can be modulated by topical application of active agents to promote optimal wound healing and improve scar quality. Thus, the myofibroblast may represent an important target for wound‐healing modulation to improve the evolution of conditions such as hypertrophic scars. The purpose of this work is to study the modulation of myofibroblasts and integrin αvβ3 in a full thickness wound performed on rabbits treated with different topical agents using: (1) saline, (2) Tegaderm occlusive dressing (3) silver sulfadiazine and (4) moist exposed burn ointment (MEBO). The reepithelialisation was 4 days faster in the MEBO group compared with the other therapies with less oedema formation, delayed contraction, less inflammatory cells and the lowest transepidermal water loss (TEWL) resulting in a soft scar. Although α‐smooth muscle actin (α‐SMA) was the highest around day 12 in the MEBO group, wound contraction and myofibroblast's activity were the least for the same period probably because of a downregulation of the integrin αvβ3. It seems that the effect of MEBO could be more pronounced on force transmission rather then on force generation. Greater insight into the pathology of scars may translate into non surgical treatments in the future and further work in myofibroblast biology will eventually result in efficient pharmacological tools, improving the evolution of healing and scar formation.     

Gasoline exhaust damages spermatogenesis through downregulating α6‐integrin and β1‐integrin in the rat model

The health influence of air pollution has been an international public health concern. Increasing evidence has suggested that air pollution has been associated with decreased sperm quality. However, the underlying molecular mechanisms are still not fully elucidated. We aimed to verify whether gasoline exhaust leads to reproductive impairment by injuring spermatogonial stem cells and explore its underlying molecular mechanism. Twenty male Sprague‐Dawley rats were randomly divided into two groups: the exposure group (n = 10) and the control group (n = 10). After 6‐month exposure, the sperm count and morphology were determined. The histological changes in the seminiferous tubules were examined by HE staining. The expression of α6‐integrin and β1 ‐ integrin was assessed with Quantitative RT‐PCR, Western blot and Immunohistochemical staining. Compared with control group, male rats exposed to gasoline exhaust showed significantly reduced sperm count, increased sperm abnormality rate and the total number of spermatogonia, primary spermatocytes, secondary spermatocytes, spermatids were decreased. (all p < .01). The expression levels of α6‐integrin and β1 ‐ integrin in the exposure group were significantly lower than those in the control group (all p < .01). Our study showed that exposure to gasoline exhaust caused impairment to spermatogonial stem cells through downregulating α6‐integrin and β1 ‐ integrin.     

α2β1 integrin and RhoA mediates electric field‐induced ligament fibroblast migration directionality

Guided cell migration is important in tissue development, repair, and engineering. We have previously demonstrated that applied electric fields (EFs) enhanced and directed ligament fibroblast migration and collagen production, depending on EF parameters. Electrical stimulation is widely used for the treatment of pain and to promote wound healing. In orthopaedic practices, applied EFs promote bone healing and ligament repair in vivo. In the current study, stimulation waveforms used in physical therapy for promoting tissue repair were adapted to examine their effects on ACL fibroblast migration. Using different waveform and field strengths, we discovered a decoupling of cell motility and directionality, which suggests disparate mechanisms. Integrin, a major extracellular matrix receptor, polarized in response to applied EFs and controlled cell directionality and signaling. Furthermore, we demonstrated that RhoA is a mediator between integrin aggregation and directed cell migration. Polarization is essential in directed cell migration and our study establishes an outside‐in signaling mechanism for EF‐induced cell directionality. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31: 322–327, 2013     

Regulation of the friction coefficient of articular cartilage by TGF‐β1 and IL‐1β

Articular cartilage functions to provide a low‐friction surface for joint movement for many decades of life. Superficial zone protein (SZP) is a glycoprotein secreted by chondrocytes in the superficial layer of articular cartilage that contributes to effective boundary lubrication. In both cell and explant cultures, TGF‐β1 and IL‐1β have been demonstrated to, respectively, upregulate and downregulate SZP protein levels. It was hypothesized that the friction coefficient of articular cartilage could also be modulated by these cytokines through SZP regulation. The friction coefficient between cartilage explants (both untreated and treated with TGF‐β1 or IL‐1β) and a smooth glass surface due to sliding in the boundary lubrication regime was measured with a pin‐on‐disk tribometer. SZP was quantified using an enzyme‐linked immunosorbant assay and localized by immunohistochemistry. Both TGF‐β1 and IL‐1β treatments resulted in the decrease of the friction coefficient of articular cartilage in a location‐ and time‐dependent manner. Changes in the friction coefficient due to the TGF‐β1 treatment corresponded to increased depth of SZP staining within the superficial zone, while friction coefficient changes due to the IL‐1β treatment were independent of SZP depth of staining. However, the changes induced by the IL‐1β treatment corresponded to changes in surface roughness, determined from the analysis of surface images obtained with an atomic force microscope. These findings demonstrate that the low friction of articular cartilage can be modified by TGF‐β1 and IL‐1β treatment and that the friction coefficient depends on multiple factors, including SZP localization and surface roughness. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27:249–256, 2009