Effect of two postpartum intramuscular treatments with β-carotene (Carofertin®) on the blood concentration of β-carotene and on the reproductive performance parameters of dairy cows

The aim of the study was to determine whether two postpartum intramuscular treatments with 200 mg of beta-(β-)carotene (Carofertin; Alvetra u. Werfft, Vienna, Austria) in a 14-day interval increases β-carotene concentrations in blood, particularly around the time of the first artificial insemination (AI), and to test the effect of the treatment on fertility parameters, luteal size, and progesterone blood levels of dairy cows. A total of 297 Holstein dairy cows were enrolled in the study. Between 28 and 34 days postpartum (dpp) β-carotene concentrations were measured in blood samples using an on-site test (iCheck carotene; BioAnalyt, Teltow, Germany). Cows with a β-carotene concentration <3.5 mg/L, indicating a deficiency of β-carotene, were allocated either to the β-carotene treatment group BCT (n = 123) or to the control group CON (n = 121). Cows with concentrations ≥3.5 mg/L were assigned to an optimally supplied reference group (REF; n = 53). Cows in the BCT group received 200 mg of β-carotene intramuscularly at 28-34 dpp and at 42-48 dpp. Further blood samples were collected at 35-41 dpp, 42-48 dpp, 49-55 dpp, and in the week after the first AI and their β-carotene concentrations were analyzed. Between day 10 and 14 after the first AI, the blood progesterone concentration was measured and the size of the corpus luteum (CL) was determined by ultrasound. Blood β-carotene concentrations increased in the BCT cows in the week after the treatment with a peak at 49-55 dpp and were significantly higher than in the CON group at each time point after the first treatment. Logistic regression models, however, revealed that the treatment with β-carotene had no effect on first service conception rate, days to first service, time to pregnancy, or percentage of pregnant cows within 150 dpp. Furthermore, there was no effect on progesterone concentration or the size of the CL between the groups. In conclusion, two treatments with Carofertin postpartum increased β-carotene blood concentrations but had no effect on the fertility parameters in this study.

Moderate cyclic tensile strain alters the assembly of cartilage extracellular matrix proteins in vitro

Mechanical loading influences the structural and mechanical properties of articular cartilage. The cartilage matrix protein collagen II essentially determines the tensile properties of the tissue and is adapted in response to loading. The collagen II network is stabilized by the collagen II-binding cartilage oligomeric matrix protein (COMP), collagen IX, and matrilin-3. However, the effect of mechanical loading on these extracellular matrix proteins is not yet understood. Therefore, the aim of this study was to investigate if and how chondrocytes assemble the extracellular matrix proteins collagen II, COMP, collagen IX, and matrilin-3 in response to mechanical loading. Primary murine chondrocytes were applied to cyclic tensile strain (6%, 0.5 Hz, 30 min per day at three consecutive days). The localization of collagen II, COMP, collagen IX, and matrilin-3 in loaded and unloaded cells was determined by immunofluorescence staining. The messenger ribo nucleic acid (mRNA) expression levels and synthesis of the proteins were analyzed using reverse transcription-polymerase chain reaction (RT-PCR) and western blots. Immunofluorescence staining demonstrated that the pattern of collagen II distribution was altered by loading. In loaded chondrocytes, collagen II containing fibrils appeared thicker and strongly co-stained for COMP and collagen IX, whereas the collagen network from unloaded cells was more diffuse and showed minor costaining. Further, the applied load led to a higher amount of COMP in the matrix, determined by western blot analysis. Our results show that moderate cyclic tensile strain altered the assembly of the extracellular collagen network. However, changes in protein amount were only observed for COMP, but not for collagen II, collagen IX, or matrilin-3. The data suggest that the adaptation to mechanical loading is not always the result of changes in RNA and/or protein expression but might also be the result of changes in matrix assembly and structure.

Stabilization effectiveness and functionality of different thumb orthoses in female patients with first carpometacarpal joint osteoarthritis

BACKGROUND

Thumb orthoses have to reconcile and satisfy competing goals: stability and mobility. The purpose of the study was to characterize the stabilization effectiveness and functionality of different thumb carpometacarpal osteoarthritis orthoses.

METHODS

Eighteen female carpometacarpal osteoarthritis subjects were included. Four orthoses were compared: BSN medical (BSN); Push braces (PUSH); Sporlastic (SPOR); and medi (MEDI). Three-dimensional thumb kinematics during active opposition-reposition with and without orthosis was quantified. Ranges-of-motion of the carpometacarpal and metacarpophalangeal joint in x- (flexion-extension), y- (adduction-abduction) and z-direction (pronation-supination) were determined. Hand functionality was examined by Sollerman test.

FINDINGS

All orthoses restricted carpometacarpal range-of-motion in all directions. In x-direction carpometacarpal range-of-motion was smallest with MEDI and BSN, in y-direction largest with PUSH compared to all other orthoses, in z-direction smaller with BSN and MEDI compared to PUSH, but similar to SPOR. All orthoses restricted metacarpophalangeal range-of-motion in x-direction, except PUSH. In x-direction metacarpophalangeal range-of-motion was smallest with MEDI compared to all other orthoses. In y-direction and z-direction only BSN and MEDI restricted metacarpophalangeal range-of-motion. Sollerman score was highest with PUSH, lowest with MEDI and both differed from other orthoses. Values for BSN and SPOR were similar and lay between PUSH and MEDI.

INTERPRETATION

Stabilization is borne by functionality. The high stabilization effectiveness provided by MEDI resulted in lowest hand functionality. PUSH, which partially stabilized the CMC joint and allowed large motions in the MCP joint, afforded largest hand functionality. Best compromise of stability and functionality could be reached with BSN. Long-term studies are needed to monitor clinical efficacy.

Effect of carpometacarpal joint osteoarthritis, sex, and handedness on thumb in vivo kinematics

PURPOSE

To investigate the influence of trapeziometacarpal (TMC) osteoarthritis (OA) on the 3-dimensional motion capability of the TMC and thumb metacarpophalangeal (MCP) joints. In order to examine other factors affecting the thumb's motion kinematics, we further aimed to address the influence of sex and handedness on the motion capability of normal TMC and MCP joints.

METHODS

We included 18 healthy subjects (9 women, 9 men; 8 dominant hands, 10 nondominant hands) and 18 women with stage II/III TMC OA. A motion analysis system using surface markers was used to quantify the thumb's 3-dimensional opposition-reposition kinematics. The range of motion of the thumb's TMC and MCP joints in flexion-extension, abduction-adduction, and pronation-supination were determined.

RESULTS

TMC OA led to a loss in abduction-adduction in the TMC joint (38° in controls, 26° in TMC OA subjects), although neither flexion-extension nor pronation-supination were affected. At the MCP joint, the TMC OA subjects showed a 48% reduction in abduction-adduction (32° controls, 16° TMC OA subjects) and 42% reduction in pronation-supination (34° in controls, 20° in TMC OA subjects) than the healthy controls. Ranges of motion of the healthy TMC and MCP joints were similar in dominant and nondominant hands as well as in women and men.

DISCUSSION

The study demonstrated that stage II/III TMC OA restricts the motion of the TMC joint in abduction-adduction and of the MCP joint in abduction-adduction and pronation-supination. Thumb motion capability was unaffected by sex and handedness.

CLINICAL RELEVANCE

Osteoarthritis-induced loss of TMC motion did not reflect a generalizable clinical parameter, rather, it seemed to distinctly affect the TMC and the MCP joints and their motion planes and directions. As neither sex nor handedness influenced the motion capabilities of the healthy thumb, kinematic factors contributing to TMC OA may develop at a later age.

Effect of whole-body vibration and insulin-like growth factor-I on muscle paralysis-induced bone degeneration after botulinum toxin injection in mice

Botulinum toxin A (BTX)-induced muscle paralysis results in pronounced bone degradation with substantial bone loss. We hypothesized that whole-body vibration (WBV) and insulin-like growth factor-I (IGF-I) treatment can counteract paralysis-induced bone degradation following BTX injections by activation of the protein kinase B (Akt) signaling pathway. Female C57BL/6 mice (n = 60, 16 weeks) were assigned into six groups (n = 10 each): SHAM, BTX, BTX+WBV, BTX+IGF-I, BTX+WBV+IGF-I, and a baseline group, which was killed at the beginning of the study. Mice received a BTX (1.0 U/0.1 mL) or saline (SHAM) injection in the right hind limb. The BTX+IGF-I and BTX+WBV+IGF-I groups obtained daily subcutaneous injections of human IGF-I (1 μg/day). The BTX+WBV and BTX+WBV+IGF-I groups underwent WBV (25 Hz, 2.1 g, 0.83 mm) for 30 min/day, 5 days/week for 4 weeks. Femora were scanned by pQCT, and mechanical properties were determined. On tibial sections TRAP staining, static histomorphometry, and immunohistochemical staining against Akt, phospho-Akt, IGF-IR (IGF-I receptor), and phospho-IGF-IR were conducted. BTX injection decreased trabecular and cortical bone mineral density. The WBV and WBV+IGF-I groups showed no difference in trabecular bone mineral density compared to the SHAM group. The phospho-IGF-IR and phospho-Akt stainings were not differentially altered in the injected hind limbs between groups. We found that high-frequency, low-magnitude WBV can counteract paralysis-induced bone loss following BTX injections, while we could not detect any effect of treatment with IGF-I.

Doxycycline-induced expression of transgenic human tumor necrosis factor α in adult mice results in psoriasis-like arthritis

Objective

To generate doxycycline-inducible human tumor necrosis factor α (TNFα)–transgenic mice to overcome a major disadvantage of existing transgenic mice with constitutive expression of TNFα, which is the limitation in crossing them with various knockout or transgenic mice.

Methods

A transgenic mouse line that expresses the human TNFα cytokine exclusively after doxycycline administration was generated and analyzed for the onset of diseases.

Results

Doxycycline-inducible human TNFα–transgenic mice developed an inflammatory arthritis– and psoriasis-like phenotype, with fore and hind paws being prominently affected. The formation of “sausage digits” with characteristic involvement of the distal interphalangeal joints and nail malformation was observed. Synovial hyperplasia, enthesitis, cartilage and bone alterations, formation of pannus tissue, and inflammation of the skin epidermis and nail matrix appeared as early as 1 week after the treatment of mice with doxycycline and became aggravated over time. The abrogation of human TNFα expression by the removal of doxycycline 6 weeks after beginning stimulation resulted in fast resolution of the most advanced macroscopic and histologic disorders, and 3–6 weeks later, only minimal signs of disease were visible.

Conclusion

Upon doxycycline administration, the doxycycline-inducible human TNFα–transgenic mouse displays the major features of inflammatory arthritis. It represents a unique animal model for studying the molecular mechanisms of arthritis, especially the early phases of disease genesis and tissue remodeling steps upon abrogation of TNFα expression. Furthermore, unlimited crossing of doxycycline-inducible human TNFα–transgenic mice with various knockout or transgenic mice opens new possibilities for unraveling the role of various signaling molecules acting in concert with TNFα.

Growth-related structural, biochemical, and mechanical properties of the functional bone-cartilage unit

Articular cartilage and subchondral bone act together, forming a unit as a weight-bearing loading-transmitting surface. A close interaction between both structures has been implicated during joint cartilage degeneration, but their coupling during normal growth and development is insufficiently understood. The purpose of the present study was to examine growth-related changes of cartilage mechanical properties and to relate these changes to alterations in cartilage biochemical composition and subchondral bone structure. Tibiae and femora of both hindlimbs from 7- and 13-week-old (each n = 12) female Sprague-Dawley rats were harvested. Samples were processed for structural, biochemical and mechanical analyses. Immunohistochemical staining and protein expression analyses of collagen II, collagen IX, COMP and matrilin-3, histomorphometry of cartilage thickness and COMP staining height were performed. Furthermore, mechanical testing of articular cartilage and micro-CT analysis of subchondral bone was conducted. Growth decreased cartilage thickness, paralleled by a functional condensation of the underlying subchondral bone due to enchondral ossification. Cartilage mechanical properties seem to be rather influenced by growth-related changes in the assembly of major ECM proteins such as collagen II, collagen IX and matrilin-3 than by growth-related alterations in its underlying subchondral bone structure. Importantly, the present study provides a first insight into the growth-related structural, biochemical and mechanical interaction of articular cartilage and subchondral bone. Finally, these data contribute to the general knowledge about the cooperation between the articular cartilage and subchondral bone.

Effect of different running modes on the morphological, biochemical, and mechanical properties of articular cartilage

Mechanical loading plays an important role not solely in cartilage development, but also in cartilage degeneration. Its adaptation behavior to mechanical loading has not been clearly delineated. The aim of the study was to examine the effect of different running modes (with different muscle contraction types) on morphological, biochemical, and mechanical properties of articular cartilage in the knee of growing rats. Thirty-six female Sprague-Dawley rats were randomly assigned into a nonactive age-matched control (AMC), level (LEVEL), and 20° downhill (DOWN) running group (n = 12 each). Running groups were trained on a treadmill for 30 min/day, 5 days/week for 6 weeks. Immunohistochemical staining and analysis of expression for collagen II, collagen IX, cartilage oligomeric matrix protein (COMP), and matrilin-3, histomorphometry of femoral cartilage height and femoral COMP staining height, and indentation testing of tibial articular cartilage were performed. Rats subjected to downhill running showed a significantly (P = 0.015) higher COMP staining height and a tendentially (P = 0.084) higher cartilage height in the high-weight bearing area of femoral articular cartilage. Cartilage thickness, mechanical properties, and expression of cartilage network proteins in tibial cartilage remained unaffected by different running modes. Our data suggest that joint loading induced by eccentric muscle contractions during downhill running may lead to a site-specific adaptation.

The effect of level and downhill running on cortical and trabecular bone in growing rats

Mechanical loading is essential for bone development and prevention of age-related bone diseases. Muscular contractions during physical activity and the generated strain magnitude are primary determinants for the osteogenic response. However, the adaptation capacity of bones, especially due to different muscle contraction types, is largely unknown. In the present study we examined the effect of different running modes characterized by different muscle contraction types and loading patterns on the morphological, structural, and mechanical properties of different sites in the femur of growing rats. Thirty-six female Sprague-Dawley rats were randomly assigned to a nonactive age-matched control (AMC), a level running (LEVEL), and a 20° decline downhill running (DOWN) group (n = 12 each). Running groups were trained on a treadmill for 30 min/day, 5 days/week for 6 weeks. After death, pQCT analysis of the meta- and diaphyses, micro-CT analysis of the epiphysis, and mechanical testing of the femur were performed. The Tb.BMD in the metaphysis was significantly (P < 0.05) increased in the DOWN compared to the AMC group, whereas level running had no effect on Tb.BMD. While Young's modulus was significantly different (P < 0.05) between the DOWN and LEVEL groups, no structural alterations were found in the diaphysis between the groups. Further, subchondral trabecular bone did not show exercise-induced changes caused by the different running modes but displayed a remarkably high intraepiphyseal variability. Downhill running seems to be a potent osteogenic stimulus in the femoral metaphysis.