The test-induced warm-up effect on hamstring flexibility tests

Background

Although the effect of active warm-up (WU) on acute flexibility enhancement is well documented, the test-induced WU effect in muscle length test has not been widely studied.

Objective

This study aimed to verify the test-induced WU effect on hamstring flexibility tests.

Methods

The active knee extension (AKE) was performed using the right leg, whereas the straight leg raise (SLR) was performed using the left leg. Ten trials of AKE or SLR were performed: two as the pre-intervention trials (Pre); six as the WU intervention; and another two trials as the post-intervention (Post). During WU, subjects in the WO-Hold group performed six trials of the AKE or SLR without hold, and those in the W-Hold group performed six trials of the AKE or SLR with a 5 s hold.

Results

A significant difference was noted between Pre-AKE and Post-AKE, and between Pre-SLR and Post-SLR, respectively, in both the groups. The effect of WU is clear when performing consecutive AKE or SLR without any additional hold.

Conclusion

Practitioners should be cautious in interpreting the testing result to avoid overestimation of the treatment effect since the test itself may induce substantial WU effect to the target tissues.

The incidence of major bleeding in adult patients with urogenital and gynecological cancer being treated with direct oral anticoagulants (DOACs): a systematic review

BACKGROUND

Direct oral anticoagulants (DOACs) are the mainstay of treatment for venous thromboembolism (VTE) and non-valvular atrial fibrillation (AF), with or without an underlying cancer. Patients with cancer have a 2-3-fold increase in risk for bleeding complications compared to non-cancer patients taking anticoagulant therapy, however the incidence of bleeding for urogenital and gynecological cancers on DOACs are uncertain.

AIMS

To assess the bleeding risk associated with the use of DOACs in patients with urogenital and/or gynecological cancers.

METHOD

We conducted a systematic review of randomized controlled trials (RCTs) and prospective cohort studies to address the safety of DOACs for VTE and AF when used in patients with urogenital and/or gynecological malignancy. The primary outcomes assessed were major and clinically relevant non-major (CRNMB) bleeding, with minor bleeding considered as a secondary outcome. MEDLINE, EMBASE and COCHRANE Central Registry of Controlled Trials were searched up to and including Oct 28, 2022. The study protocol was registered in PROSPERO (CRD42022370981). Studies were independently assessed for inclusion and data extracted in duplicate.

RESULT

Seven studies met our inclusion criteria (Fig. 1): 2 RCTs and 5 prospective cohort studies. A total of 676 patients treated with DOACs were included, 628 (92.8%) had VTE and 48 (7.1%) had AF. In patients with VTE treated with DOACs, the pooled major bleeding rate was 2.1%, 95% confidence intervals (CI) 0.9-3.3% (Fig. 2). Pooled estimates could not be determined for AF patients given small event and patient numbers.

CONCLUSION

Major bleeding rates in urogenital and/or gynecological cancer patients treated with DOACs are similar to that of the general cancer population.

Joint position sense error in the hip and knee without reference to the joint angle

BACKGROUND

Joint position reproduction measures the angle acuity of reference angle reproduction using an indicator angle. However, reference angles are often not available.

OBJECTIVE

This study aimed to examine joint position sense at three different targeted joint angles, which were estimated from the maximum range of motion (maxROM) without a reference angle at each targeted joint angle.

METHODS

The maxROM was measured in straight leg raise (SLR) and active knee extension (AKE) positions. In both positions, a targeted joint angle at 75% of the maxROM was assessed first, followed by that at 50% and 25% of the maxROM. A one-sample t-test was used to analyze differences between the targeted and reproduced angles in both positions.

RESULTS

All reproduced angles significantly differed from the targeted angle in both SLR and AKE positions except for the reproduced angle measured at 75% maxROM. Overall, position errors in the AKE position were higher than those in the SLR position.

CONCLUSIONS

Estimating the angle based on the maxROM without a matched reference angle may lead to significant discrepancies in comparison with the targeted joint angle. In clinical settings, if accurate reproduction of motions is required to improve proprioception, providing a reference angle might be helpful.

Effect of PNF stretching performed in the AKE position on hip, knee, and ankle flexibility

BACKGROUND

To measure hamstring flexibility, the active knee extension (AKE) test is preferred over the straight leg raise (SLR) test as it can be used to measure hamstring flexibility more selectively. However, hamstring stretching is primarily conducted in the SLR position (maximal hip flexion in the supine position) as it allows for maximal hip flexion in the supine position.

OBJECTIVE

This study evaluates the effects of proprioceptive neuromuscular facilitation (PNF) stretching in the AKE position (maximal knee extension with 90∘ flexion of the hip in the supine position) on hip, knee, and ankle flexibility.

METHODS

SLR, AKE, and active dorsiflexion (ADF) tests were used to determine the range of motion (ROM) before (pre-ROM) and after (post-ROM) stretching. PNF stretching consisted of maximal isometric knee flexion at the end range with external resistance to prevent knee flexion. One set of PNF stretches (five trials of six seconds each) was conducted.

RESULTS

The post-ROMs of hip, knee, and ankle measured via the SLR, AKE, and ADF tests, respectively, were significantly higher than the pre-ROMs.

CONCLUSIONS

The improvement in knee flexibility was greater than the improvement in hip and ankle flexibility. The AKE position is recommended in clinical settings during PNF stretching for individuals with hamstring tightness. Furthermore, PNF stretching in the AKE position increases the ADF ROM.

Comparison of muscle activity of hamstrings as knee flexors and hip extensors and effect of tibial and hip rotation on the contribution of hamstrings

BACKGROUND

Limited studies have compared the muscle activity of the medial and lateral hamstrings as knee flexors with tibial internal and external rotation and hip extensors with hip internal and external rotation. In particular, hamstring activity during hip extension with hip rotation has rarely been investigated.

OBJECTIVE

This study aimed to compare the muscle activity of the medial and lateral hamstrings as knee flexors and hip extensors and to compare the activity of these muscles according to tibial rotation during isometric knee flexion and hip rotation during isometric hip extension.

METHODS

A total of 23 healthy adults participated in the study. The electromyographic (EMG) activity of the hamstrings was measured during maximal isometric knee flexion and maximal isometric hip extension. In addition, tibial rotation was applied actively during maximal isometric knee flexion, whereas hip rotation was applied actively during maximal isometric hip extension.

RESULTS

EMG activity during maximal isometric knee flexion with tibial internal and external rotation was significantly higher than that during maximal isometric hip extension with hip internal and external rotation, respectively. For EMG activity according to tibial and hip rotation, there was no significant difference between tibial internal and external rotation during maximal isometric knee flexion, whereas there was a significant difference between hip internal and external rotation during maximal isometric hip extension.

CONCLUSION

Hamstring activity was higher for knee flexors than for hip extensors. However, hip rotation during maximal isometric hip extension is an effective intervention for selective muscle activation of the medial and lateral hamstrings.

Acute effect of diagonal stretching using the posterior oblique sling system on contralateral ankle dorsiflexion

BACKGROUND

A significant increase in the dorsiflexion range of motion (DFROM) after calf muscle stretching has been widely studied. However, it has been shown that the upper body is connected to the ankle joint by passive connective tissues.

OBJECTIVE

The purpose of this study was to examine the effect of upper-back stretching on the mobility of the contralateral ankle.

METHODS

In the supine position, DFROM in the contralateral leg was measured. In the sitting position with and without trunk rotation, DFROM was measured in both legs. In the sitting position with trunk rotation, dorsiflexion was measured only in the contralateral leg. Static diagonal stretching combining trunk rotation with slight trunk flexion was performed in the sitting position with a neutral pelvis.

RESULTS

After stretching, DFROM in contralateral and ipsilateral legs were measured in the sitting position with a neutral pelvis. In the contralateral leg, significant differences in ΔDFROM were observed between the sitting position with trunk rotation and the supine position and between the sitting position with trunk rotation and the sitting position after stretching.

CONCLUSION

In clinical settings, diagonal stretching of the unilateral posterior trunk causes a significant increase in the DFROM of the contralateral lower limb.

Effect of novel diagonal stretching combining trunk rotation and trunk flexion on contralateral knee extension

BACKGROUND: Most previous studies have focused on increasing hamstring flexibility when knee extension range of motion (KE ROM) is restricted. However, it was demonstrated that the tensile force generated in the upper body could be transmitted to the contralateral lower extremity. OBJECTIVE: This study examined the effect of novel diagonal stretching combining trunk rotation and trunk flexion on the contralateral KE ROM. METHODS: Two different positions (sitting with a neutral pelvis position and sitting with trunk rotation) were randomly selected and the contralateral and ipsilateral KE ROM was measured in each position. As for the stretching intervention, trunk rotation and slight trunk flexion were applied in sitting with a neutral pelvic position. RESULTS: On the contralateral side, KE ROM was significantly different in all pairwise comparisons (p< 0.001). On the ipsilateral side, a significant difference in KE ROM was only observed between measurements taken after stretching compared to measurements taken during trunk rotation (p= 0.005). CONCLUSIONS: The tensile force in the upper body significantly affects tissue extensibility in the lower extremity in the contralateral side, leading to the restriction of active maximum knee extension. Diagonal stretching techniques may successfully enhance mobility in the contralateral leg.

Effects of hip rotation on the electromyographic activity of the medial and lateral hamstrings and muscle force

BACKGROUND

In clinical practice, knee flexion at the prone position for manual muscle testing of hamstrings and hip extension at the supine position for stretching of hamstring muscles are typically proposed.

OBJECTIVE

Although different positions have been proposed for different purposes in hamstrings, the understanding of the changing the functional role of hamstrings with position changes is poorly understood.

METHODS

The electromyographic (EMG) activity and hip extension force were compared among different postures; hip neutral, internal, and external rotation. EMG and force were measured in prone position during knee flexion and those were additionally measured in supine position during hip extension. In supine position, additional measurements were made in hip neutral, internal and external rotation.

RESULTS

Hamstrings showed high EMG activity during knee flexion. Knee flexion force in prone position was significantly decreased at hip extension force in supine position. In supine position, EMG activity was significantly higher in semitendinosus (ST) than biceps femoris (BF) during internal rotation.

CONCLUSIONS

It should be noted that bi-articular muscles may have different functional dependencies on the corresponding muscles for each joint. In addition, because the altered alignment of the hamstring muscles that was affected by hip rotation had a significant effect on muscle activity, and hip rotation may be helpful for selective training of medial or lateral hamstrings.

Long-term outcomes of catheter ablation for ventricular arrhythmias in post- myocarditis patients; Insights from a meta-analysis of current datv

Background

In the past decade, catheter ablation (CA) has become a rapidly expanding treatment option for ventricular tachycardia (VT), however it is not commonly utilized for patients with post-myocarditis VT. We aimed to systematically review up-to-date evidence regarding feasibility, effectiveness, and safety of CA, with a specific focus on long-term relapse rate and procedural complications.

Methods

A structured electronic database search (PubMed, Embase, Cochrane) of the scientific literature was performed for studies describing outcomes at up to 7.3 years after CA. The primary outcome measured was VT recurrence post-ablation. Procedural success was defined as freedom of ventricular arrhythmias (at the end of follow-up after an ablation procedure). The secondary outcome was significant procedural complications which included procedural death, stroke, cardiac tamponade, acute myocardial infarction, major vascular complications, and major bleeding, assessed on a study-by-study basis.

Results

A total of 186 patients were included in analysis with most patients (88%) being male.

Over the follow up period there was a 18% relapse rate (n=34) (Confidence Interval (CI); 0.12–0.24, I2≈0, p=0.77) with the majority of patients remaining VT free for the duration of follow up. Only one study recorded the percentage of re-do procedures. The overall procedural complication rate was 3.0% (n=7, (CI; 0.01–0.07, I2≈0, p=0.44) and of note, there were no peri-procedural deaths or heart transplant surgeries reported. However, a single study reported a mortality of 10% (n=2) during the follow up period.

Conclusions

CA is an effective and durable long-term therapeutic strategy for post myocarditis VT patients with limited relapse rate and very low complication rates based on these non-randomised data. Larger randomised-controlled trials with standardised treatment and long follow-up are required to compare CA versus conventional treatment in the post-acute myocardial phase.

Funding Acknowledgement

Type of funding sources: None. Relapse rate during follow-upProcedural complication rate

Influence of submaximal isometric contractions of the hamstrings on electromyography activity and force while functioning as hip extensors

BACKGROUND: Although the medial and lateral hamstrings are clearly distinct anatomically and have different functions in the transverse plane, they are often considered as one muscle during rehabilitation. OBJECTIVE: The purpose of the study was to compare the electromyographic (EMG) activity between the prone position and the supine position during maximal isometric contraction and to additionally confirm the effect of submaximal isometric contractions on EMG activity of medial and lateral hamstrings, and force. METHODS: In the prone position, EMG activities of the long head of biceps femoris (BFLH) and semitendinosus (ST) were measured during the maximal isometric contraction. In the supine position, hip extension force with EMG activity were measured during the maximal and the submaximal isometric contractions. RESULTS: EMG activity in the prone position was significantly decreased in the supine position. In the supine position, there was a significant difference between the BFLH and ST during the maximal isometric contraction, but not during the submaximal isometric contractions. CONCLUSIONS: The dependence on the hamstrings could be relatively lower during hip extensions. When the medial and lateral hamstrings are considered separately, the lateral hamstrings may show a more active response, with increased muscle length, in clinical practice.

The effect of parenting styles on enforcement of oral health behaviours in children

PURPOSE

To examine the relationship between parenting styles and parental attitudes towards oral health practices in children.

METHODS

Parents of children aged 4-6 years presenting to four public dental clinics completed the Parenting Styles Dimensions Questionnaire (PSDQ) and a questionnaire on parental attitudes, child diet and oral hygiene practices. Child oral health was evaluated using Plaque Index (PI) and dmft-Index.

RESULTS

Three hundred and eighty-nine children (mean age: 62.3 ± 9.8 months) were recruited. The median dmft was 4 (IQR = 9) and median PI was 1.5 (IQR = 0.8). An authoritative parenting style was observed in 95.1% of parents. Authoritative parents were more likely to monitor sweets/snacks intake (P = 0.004) and less inclined to offer sweets/snacks in exchange for good behaviour (P = 0.04) than permissive parents. However, actual between-meal snacking frequency did not differ between styles (P = 0.43). Permissive parents were less likely to ensure bedtime toothbrushing (P = 0.001) or brush thoroughly when busy or tired (P = 0.03) compared to authoritative parents; these attitudes were associated with higher frequencies of actual omission of bedtime toothbrushing (P = 0.006) in their children. A higher frequency of omitting bedtime toothbrushing significantly predicted a permissive parenting style (OR = 12.1, P = 0.009). Parenting styles were not associated with dmft (P = 0.72) and/or PI (P = 0.34).

CONCLUSIONS

Authoritative parenting was associated with positive attitudes regarding both preventive dietary and oral hygiene practices. Actual oral hygiene practices were more ideal in children with authoritative parents, but parenting styles had no impact on actual dietary habits.

Effects of upper-extremity movements on electromyographic activities of selected trunk muscles during leaning forward

BACKGROUND

Leaning forward has been accepted as a foundational approach to facilitate trunk-stabilizing muscles in the abdominal and lumbopelvic regions for patients with back pain during rehabilitation. However, how trunk muscles are activated and recruited during leaning forward performed under dynamic upper-extremity motion conditions is not completely understood.

OBJECTIVE

To determine whether activation of selected trunk muscles changes depending on shoulder movements during leaning forward exercise in healthy young adults.

METHODS

Twenty-four healthy adults (6 men and 18 women) participated in this study. The participants performed 3 types of leaning forward exercises: leaning forward alone (leaning forward 1), leaning forward with horizontal shoulder abduction (leaning forward 2), and leaning forward with shoulder flexion (leaning forward 3). Surface electromyography (EMG) was used to record activation of the erector spinae (ES), multifidus (MF), rectus abdominis (RA), and internal oblique (IO) on the dominant side.

RESULTS

There was a significant main effect of exercise type on the activation of the IO, RA, and MF muscles. Activation of the IO and MF during leaning forward 1 was significantly decreased compared to activation in leaning forward 2 and 3; the activation of IO and RA showed the greatest increase during leaning forward 3. Furthermore, the IO/RA ratio was significantly increased during leaning forward 2 and 3 in comparison to leaning forward 1; the MF/ES ratio was also significantly increased during leaning forward 3, compared with leaning forward 1.

CONCLUSION

The integration of shoulder movements during leaning forward exercises could be effective in the facilitation of EMG activity of IO and MF muscles, especially with shoulder flexion.

Effects of proprioceptive neuromuscular facilitation stretching at low-intensities with standing toe touch on developing and maintaining hamstring flexibility

BACKGROUND

Proprioceptive neuromuscular facilitation (PNF) stretching at low intensities has been rarely investigated. Previous studies have shown that hamstring flexibility after stretching is only temporary.

OBJECTIVE

The aim of this study was to assess the effect of low intensities (40% and 10% of maximum voluntary isometric contraction, MVIC) of PNF stretching on hamstring muscles and to assess the effect of standing toe touch on the duration of hamstring flexibility.

METHODS

This was a single-blind randomized controlled trial. Sixty-four healthy adults (age, 22.67 ± 1.73 years) were selected and divided into four groups: 40% intensity PNF stretching (P40), 10% intensity PNF stretching (P10), 40% intensity PNF stretching with toe touch (P40 with TT), and 10% intensity PNF stretching with toe touch (P10 with TT). Hamstring flexibility was measured using the active knee extension test (pre-stretching, post-stretching, and 3, 6, 9, 12, and 15 min after PNF stretching).

RESULTS

In the P40, P40 with TT, and P10 with TT groups, significant changes were observed at all time points after stretching (p < 0.05). In the P10 group, significant changes were only observed immediately post stretching (p = 0.006) and at 3 min (p = 0.029) after stretching. In terms of maintaining the duration of flexibility, the P40 with TT and P10 with TT groups were superior to the P40 and P10 groups.

CONCLUSION

PNF stretching at low intensity, approaching 40% of MVIC, led to more flexibility than 10% MVIC. Additionally, standing toe touch after PNF stretching is recommended to develop and maintain hamstring flexibility.

Modification of the RANKL-RANK-binding site for the immunotherapeutic treatment of osteoporosis

Here, we proposed the use of mutated RANKL as an immunogen for active immunization and to induce anti-cytokine antibodies for osteoporosis treatment.

INTRODUCTION

Osteoclasts are responsible for bone resorption in bone-related disorders. Anti-cytokine therapeutic antibodies such as denosumab are effective for the treatment of osteoporosis. However, problems with antibody manufacturing and the immunogenicity caused by multiple antibody doses have led to the use of auto-cytokines as immunogens to induce anti-cytokine antibodies.

METHODS

RANKL was point-mutated based on the crystal structure of the complex of RANKL and its receptor RANK.

RESULTS

As a proof of concept, immunization with RANKL produced high levels of specific antibodies and blocked osteoclast development in vitro and inhibited osteoporosis in RANKL-treated or ovariectomized mouse models.

CONCLUSIONS

The results demonstrate the successful use of mutated RANKL as an immunogen for the induction of anti-RANKL immune response. This strategy is useful in general anti-cytokine immunotherapy to avoid toxic side effects of osteoporosis treatment.

Initial experience with the convergent procedure for longstanding persistent atrial fibrillation: A 5 year dataset

In patients with longstanding persistent atrial fibrillation (AF), outcomes from catheter ablation remain suboptimal. The convergent procedure combines minimally invasive surgical ablation with subsequent catheter ablation, and may contribute towards maintenance of sinus rhythm in this patient group. We performed the convergent procedure on 43 patients with longstanding persistent AF from 2013–2018. Patients underwent clinical review at 3, 6, and 12 months and thereafter as necessitated by their symptoms. Our dataset describes patients’ baseline characteristics and rhythm control protocols, as well as outcomes including arrhythmia recurrence, the need for antiarrhythmic drugs, requirement for repeat rhythm control procedures, and complications. These data provide a real world insight into the risks and benefits of the convergent procedure in patients with longstanding persistent AF.

Abstract P2-02-09: Not presented

This abstract was not presented at the conference.

Citation Format: An J, Yang J, Lee W-H, Kim JB, Kim J-k, Kim H, Paek SH, Lee JW, Woo J, Kwon H, Lim W, Paik NS, Kim Y-K, Moon B-I. Not presented [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-02-09.

Easy method for measuring stretching intensities in real clinical settings and effects of different stretching intensities on flexibility

BACKGROUND

Flexibility changes according to stretching intensity have been rarely investigated. I aimed to assess the effect of different stretching intensities on hamstring flexibility by measuring them in a setting similar to real clinical settings.

METHODS

Stretching intensities were quantified using an easy method, and participants were grouped according to intensity: 100% (P100), 70% (P70), 40% (P40), and 10% (P10) of maximum voluntary isometric contraction. Proprioceptive neuromuscular facilitation stretching intensities were measured using a sling system and tension dynamometer. Hamstring flexibility was measured (before; immediately after; and 3, 6, 9, 12, and 15 min after stretching) using the active knee extension test. Flexibility was compared between subgroups, and longitudinal changes in flexibility were additionally observed in each group.

RESULTS

At identical time points, no significant difference in hamstring flexibility was found between the high-intensity (P100) and moderate-intensity (P70, P40) groups. A significant difference was found between P100 and P10 immediately after and 12 and 15 min after stretching. Increased flexibility was maintained until the end in P100 and P70 but not P40 and P10.

CONCLUSIONS

High-intensity and moderate-intensity stretching increases flexibility compared with low-intensity stretching. Furthermore, high-intensity stretching was superior to moderate-intensity stretching in terms of maintaining flexibility over time.

Optimal intensity of PNF stretching: maintaining the efficacy of stretching while ensuring its safety

[Purpose] To investigate changes in hamstring flexibility in relation to intensity of proprioceptive neuromuscular facilitation stretching and changes in pain over time, and examine the correlations between pain level and target intensity or flexibility gain. [Participants and Methods] Sixty-one healthy adults were randomly divided into 4 groups (100% [P100], 70% [P70], 40% [P40], and 10% [P10] of maximum voluntary isometric contraction) according to intensity of hold-relax stretching. Hamstring flexibility was measured with the active knee extension test, and pain was measured using the visual analogue scale. [Results] Concerning hamstring flexibility, P100 showed significant differences from P40 and P10, and P70 was significantly different from P10. At post-stretch, P100 significantly differed from P70, P40, and P10 in visual analogue scale. At 1 day, P100 significantly differed from P40 and P10. Although there was a significant correlation between post-stretch pain level and stretching intensity, there was no significant correlation between pain level and flexibility improvement. [Conclusion] Repetitive high-intensity stretching may cause heavy burden on muscle tissues, and pain caused by high-intensity stretching can hinder muscle performance. Moderate stretching intensity is recommended and considered conducive to maintaining the effects of stretching while ensuring its safety.

Adiponectin: A prosurvival and proproliferation signal that increases bovine mammary epithelial cell numbers and protects them from endoplasmic reticulum stress responses

Cell-cell interactions between epithelial and stromal cells are predominant in the mammary gland, and various stromal cell-derived factors can elicit mitogenic responses in adjacent epithelial cells. Adiponectin is a hormone secreted mainly by adipocytes that mediates stromal-epithelial interactions in a number of tissues. Adiponectin receptors are expressed by bovine mammary epithelial cells, but the regulatory effects of adiponectin on the development and function of the mammary gland remain unclear. We therefore sought to investigate the effects of adiponectin on bovine mammary epithelial (MAC-T) cells and the regulatory mechanisms that underlie these adiponectin-induced actions. Our results revealed an increase in MAC-T cell proliferation and cell cycle progression in response to adiponectin. The expression of nuclear proliferating cell nuclear antigen (PCNA) and cyclin D1 was induced in MAC-T cells, and intracellular signaling molecules such as serine/threonine protein kinase (AKT), 70 kDa ribosomal S6 kinase (P70S6K), ribosomal protein S6 (S6), extracellular signal-regulated kinases 1 and 2 (ERK1/2), 90 kDa ribosomal S6 kinase (P90S6K), and cyclin D1 were activated in a dose-dependent manner. The abundance of adiponectin-induced signaling proteins was suppressed following inhibition of AKT or ERK1/2 mitogen-activated protein kinase (MAPK) signaling. In addition, inhibition of AKT or ERK1/2 signaling significantly reduced adiponectin-stimulated MAC-T cell proliferation. Furthermore, adiponectin reduced tunicamycin-induced expression and activation of endoplasmic reticulum stress-related proteins in MAC-T cells and attenuated the repressive effect of tunicamycin on proliferation of MAC-T cells. Collectively, these results suggest that adiponectin-mediated signaling may affect the development and function of the mammary gland in dairy cows by increasing mammary epithelial cell numbers. These findings may result in important implications for improving our fundamental understanding of lactation physiology in livestock species.

The functional effects and mechanisms by which fibroblast growth factor 2 (FGF2) controls bovine mammary epithelial cells: Implications for the development and functionality of the bovine mammary gland

Fibroblast growth factor (FGF) signaling plays essential roles in tissue development and homeostasis. Accumulating evidence reveals that fibroblast growth factor 2 (FGF2) regulates ductal elongation, which requires cell proliferation and epithelial expansion in the mammary gland. However, the function and mechanisms by which FGF2 controls functionality of epithelial cells is less well defined. Here, we demonstrate the functional effects of FGF2 on bovine mammary epithelial (MAC-T) cells and the intracellular signaling mechanisms for these FGF2-induced actions. The current results show that treatment of MAC-T cells with a recombinant FGF2 induced cell proliferation and cell-cycle progression with increased expression of proliferating cell nuclear antigen and cyclin D1. Moreover, FGF2 increased phosphorylation of serine/threonine protein kinase (protein kinase B [AKT]), extracellular signal-regulated kinases 1 and 2 (ERK1/2), Jun N-terminal kinase (JNK), 70 kDa ribosomal S6 kinase (P70S6K), 90 kDa ribosomal S6 kinase (P90S6K), ribosomal protein S6 (S6), and cyclin D1 proteins. These FGF2-induced activations of signaling pathway proteins were inhibited by blocking AKT, ERK1/2, or JNK phosphorylation. The effect of FGF2 to stimulate MAC-T cell proliferation was mediated by activation of FGF receptors (FGFR) and AKT, ERK1/2, and JNK mitogen-activated protein kinase pathways in response to FGF2 stimulation. Furthermore, expression and activation of endoplasmic reticulum (ER) stress-related factors and ER stress-induced MAC-T cell death was reduced by FGF2. Together, these results suggest that the FGF2-FGFR-intracellular signaling cascades may contribute to maintaining and/or increasing numbers of mammary epithelial cells by inducing proliferation of mammary epithelial cells and by protecting cells from ER stress responses. Therefore, this study provides evidence that FGF2 signaling is a positive factor for mammary gland remodeling and for increasing persistency of milk production.

Dicer1, AGO3, and AGO4 microRNA machinery genes are differentially expressed in developing female reproductive organs and overexpressed in cancerous ovaries of chickens

MicroRNA (miRNA)-mediated gene silencing is a key mechanism regulating numerous biological processes such as development of organs and tumorigenesis. The expression of miRNA machinery genes linked to miRNA biogenesis and processing is finely regulated. Despite accumulating evidence for chicken miRNA in the female reproduction system, precise regulatory mechanisms are largely unknown. Therefore, the objective of this study was to determine changes in expression levels of miRNA machinery genes in developmental stages of the oviduct and ovarian carcinogenesis of laying hens. In the present study, differential expression of miRNA machinery genes during ovarian carcinogenesis was determined using cancerous and normal ovaries collected from normal laying hens and hens with cancer. Our results showed that 3 miRNA machinery genes (, , and ) were differentially expressed as laying hens' reproductive organs developed. These genes were simultaneously upregulated in cancerous ovaries compared with those in normal ovaries. Their transcripts were abundantly localized in glandular epithelial cells of cancerous ovaries. Our results indicate that , , and play critical roles in the development of reproductive organs and ovarian carcinogenesis in laying hens, suggesting that simultaneous overexpression of these genes might serve as a prognostic factor for ovarian cancer.

Differential expression of neuregulin 1 (NRG1) and candidate miRNA regulating NRG1 transcription in the chicken oviduct in response to hormonal changes

Neuregulin 1 (NRG1), a signaling protein that binds to members of the erythroblastoma (ErbB) family, is known to play essential biological roles in mediating cell-cell interactions and orchestrating vital cell functions in the heart and nervous system. NRG1 is closely associated with developmental processes in various organs and expression of several NRG1 isoforms are regulated by estrogen. However, expression and its hormonal regulation during development of the female reproductive tract remain unknown. The reproductive system of chickens undergoes dynamic morphological and functional changes in response to estrogen and the molting process. Therefore, in the current study, we found differential expression of and candidate microRNA regulating chicken transcription in response to estrogen stimulation and/or the molting process. The results revealed that relative expression of mRNA increased in the oviducts of chicks treated with diesthylstilbestrol (DES; a synthetic non-steroidal estrogen). Additionally, abundant NRG1 mRNA expression was primarily in the glandular (GE) and luminal (LE) epithelia of the magnum in the developing chick oviduct in response to exogenous estrogen. Also, expression decreased during regression of the oviduct following induced molting by feeding high levels of zinc in the diet, and then gradually resurged as the oviduct underwent remodeling and recrudescence in laying hens. In addition, the present results revealed changes in relative expression of candidate chicken microRNA (, and ) targeting transcription in chicken oviducts in response to exogenous estrogen. In conclusion, these results provide the first evidence that is a novel estrogen-responsive gene closely correlated with the estrogen-dependent development of the oviduct of chicks and regeneration of the oviduct after molting. Further, regulation of expression involving at least 3 chicken miRNA is likely a prerequisite for those estrogen regulated developmental events.

The efficacy of virtual reality assisted versus traditional rehabilitation intervention on individuals with functional ankle instability: a pilot randomized controlled trial

PURPOSE

Virtual reality (VR) training, a virtual environment commonly generated by computer systems, may enhance the therapeutic efficacy of functional rehabilitation programmes. The aim of this study was to investigate the efficacy of a VR assisted intervention (VRAI) versus traditional rehabilitation intervention (TRI) on functional ankle instability (FAI).

METHODS

A single-blind randomized controlled study was conducted with 10 subjects for each group. The VRAI was conducted with the Nintendo Wii Fit Plus, whilst the TRI was conducted with a series of exercises with theraband. The muscle strength change of the two groups and the difference between pre and post interventions for each group were compared.

RESULTS

The VRAI group had less improvement in the muscle strength of all ankle motions than did the TRI group (p > .05). The VRAI group had a greater improvement in muscle strength of plantar flexion than other motions, whilst the TRI group had an improvement in muscle strength of all ankle motions (p < .05).

CONCLUSIONS

The effects of VR training for the condition of FAI were not comparable to conventional training. However, VR training may be added to the conventional training programme as an optional for the condition of FAI. Implications for Rehabilitation Functional ankle instability (FAI) is subjective feelings of ankle instability resulting from proprioceptive and neuromuscular deficits in which individuals may experience "giving way" condition of the ankle. Therapeutic applications of virtual reality (VR) may be comparable to traditional rehabilitation interventions (TRI) in the rehabilitation of individuals with FAI. However, there is no definitive evidence for the issue. Integrating low-cost VR into functional rehabilitation programme can provide insight into an issue of whether it can be replaced with traditional therapeutic approaches. Although, the efficacy of VR application on strengthening muscles is unable to compare to traditional strengthening programmes, it may be considered an optional treatment based on the proprioceptive improvements.

No significant correlation between the intensity of static stretching and subject's perception of pain

[Purpose] The purpose of this study was to determine whether the intensity of static stretching measured quantitatively is related to subjects’ perception of pain. [Subjects and Methods] Sixty-eight participants were recruited. Static stretching was performed once for 30 seconds while maintaining the knee at 0° flexion and was continued to the point where pain was recognized. The intensity of stretching exerted by the practitioner was quantitatively measured by using a handheld dynamometer (HHD). A subject’s pain scaled on one’s perception was measured by using the visual analog scale (VAS). [Results] No significant correlation was found between the intensity of stretching and the VAS score representing the subject’s pain scaled on one’s perception. In this study, the most frequent VAS score was 7, and the mean VAS score was 5.57 ± 1.77. The stretching intensity measured by using a HHD ranged from 28.4 to 133.0 N (mean, 72.04 ± 22.37 N). [Conclusion] This study showed that the intensity of stretching quantitatively measured by using HHD did not correlate with the degree of pain reported by the subjects. Therefore, subjective responses cannot guarantee a consistent application of intensity.

Rapid Communication: MicroRNA co-expression network reveals apoptosis in the reproductive tract during molting in laying hens

The aim of this study was to determine the regulatory mechanisms of molting and recrudescence via studying the micro-RNA (miRNA) expression in the oviduct of laying hens. We performed a cDNA microarray analysis in the magnum tissue from the oviduct to identify the whole miRNA profiles through the molting and recrudescence periods. A total of 35 laying hens (47-wk-old) were divided into 7 groups (0 d: a control group; 6 and 12 d: 2 molting-period groups fed on a high-zinc diet; and 20, 25, 30, and 35 d: 4 recrudescence-period groups fed on a normal diet after a 12-d period on a high-zinc diet). An miRNA co-expression network (miRCN) was generated using the differentially expressed miRNA (DEM) according to the entire data integration. The significantly co-expressed miRNA ( = 111) were highly differentially expressed from 12 to 20 d, which was a transition period between molting and recrudescence, while their expression patterns were contrary to the estrogen changes. The targets of highly connected miRNA ( = 12) indicated the significant biological pathways and gene ontology (GO) terms, such as MAPK and Wnt signaling and magnesium-ion binding, which are associated with apoptotic activities. These results suggest that the miRNA of the miRCN might play a role in the apoptotic progression of the reproductive tract during molting.