Immediate effects of visuomotor tracking with the head on cervical sensorimotor function and pain in chronic neck pain patients

BACKGROUND

Working in awkward and sustained postures is, besides psychosocial risk factors, the most reported physical risk factor for neck pain. Accurate proprioception is fundamental to correcting awkward head-to-trunk positions, but impaired proprioceptive performance has been found in patients with chronic neck pain.

OBJECTIVE

The aim was to compare the effectiveness of two different interventions in a workplace set-up on sensorimotor performance and pain sensitivity in people with chronic neck pain.

METHODS

A total of 25 patients with chronic neck pain participated in this double-blind study. Patients were randomly allocated to the visuomotor tracking task group or the video group (watching a massage video, imagining themselves being massaged). The primary outcomes were cervical joint position sense acuity and pressure pain threshold of the cervical spine, evaluated by a blinded assessor.

RESULTS

There were significant time by group interactions for cervical joint position sense acuity (F1;23: 4.38; p= 0.048) and pressure pain threshold (F1;23: 5.78; p= 0.025), with the tracking task group being more accurate in cervical joint position sense testing and less pain sensitive for pressure pain threshold.

CONCLUSIONS

The visuomotor tracking task improves cervical joint position sense acuity and reduces pressure pain threshold immediately after intervention in people with chronic neck pain.

Can tibio-femoral kinematic and kinetic parameters reveal poor functionality and underlying deficits after total knee replacement? A systematic review

BACKGROUND

Extensive efforts have been made to understand joint kinematics and kinetics in total knee arthroplasty (TKA) in subjects with satisfactory outcomes during daily functional activities and clinical tests, but it remains unclear whether such movement characteristics hold the potential to indicate the underlying aetiology of unsatisfactory or bad TKA outcomes.

PURPOSE

To investigate which kinematic and kinetic parameters assessed during passive clinical tests and functional activities of daily living are associated with poor functionality and underlying deficits after total knee replacement.

METHODS

We focused on studies characterizing the kinematic or kinetic parameters of the knee joint that are associated with poor clinical outcome after TKA. Seventeen articles were included for the review, and kinematic and kinetic data from 719 patients with minimal follow up of 6 months were extracted and analyzed.

RESULTS

Passive posterior translation at 90°flexionexhibited good potential for differentiating stable and unstable TKAs. Anterior-posterior (A-P) translation of the medial condyle at 0-30° and 30-60° flexion, A-P translation of the lateral condyle at 60-90°during closed chain exercises, as well asknee extension moment during stair ascent and descent, knee abduction moment during stair descent, knee internal rotation moment and plantar flexion moment during walking, 2ndpeak ground reaction force during stair ascent and walkingshowed the greatest promise as functional biomarkers for a dissatisfied/poor outcome knee after TKA.

CONCLUSION

In this study, we systematically reviewed the state-of-the-art knowledge of kinematics and kinetics associated with functional deficits, and found 11 biomechanical parameters that showed promise for supportingdecision making in TKA.

Cervical joint position sense in neck pain. Immediate effects of muscle vibration versus mental training interventions: a RCT

BACKGROUND

Impaired cervical joint position sense is a feature of chronic neck pain and is commonly argued to rely on abnormal cervical input. If true, muscle vibration, altering afferent input, but not mental interventions, should have an effect on head repositioning acuity and neck pain perception.

AIM

The aim of the present study was to determine the short-term effects of neck muscle vibration, motor imagery, and action observation on cervical joint position sense and pressure pain threshold in people with chronic neck pain.

DESIGN

Forty-five blinded participants with neck pain received concealed allocation and were randomized in three treatment groups. A blinded assessor performed pre- and post-test measurement.

SETTING

Patients were recruited from secondary outpatient clinics in the southwest of Germany.

POPULATION

Chronic, non specific neck pain patients without arm pain were recruited for this study.

METHODS

A single intervention session of 5 minutes was delivered to each blinded participant. Patients were either allocated to one of the following three interventions: (1) neck muscle vibration; (2) motor imagery; (3) action observation. Primary outcomes were cervical joint position sense acuity and pressure pain threshold. Repeated measures ANOVAs were used to evaluate differences between groups and subjects.

RESULTS

Repositioning acuity displayed significant time effects for vibration, motor imagery, and action observation (all P<0.05), but revealed no time*group effect. Pressure pain threshold demonstrated a time*group effect (P=0.042) as only vibration significantly increased pressure pain threshold (P=0.01).

CONCLUSION

Although motor imagery and action observation did not modulate proprioceptive, afferent input, they nevertheless improved cervical joint position sense acuity. This indicates that, against the common opinion, changes in proprioceptive input are not prerequisite to improve joint repositioning performance. However, the short-term applications of these cognitive treatments had no effect on pressure pain thresholds, whereas vibration reduced pressure pain thresholds. This implies different underlying mechanisms after vibration and mental training.

CLINICAL REHABILITATION IMPACT

Mental interventions were effective in improving cervical joint position sense and are easy to integrate in rehabilitation regimes. Neck muscle vibration is effective in improving cervical joint position sense and pressure pain thresholds within 5 minutes of application.

Hepatic TLR2 & TLR4 expression correlates with hepatic inflammation and TNF-α in HCV & HCV/HIV infection

Signalling activated by Toll-like receptors (TLRs) can result in the production of tumour necrosis factor alpha (TNF-α) which is implicated in hepatitis C virus (HCV) and human immunodeficiency virus (HIV) infection. No study has examined or compared hepatic expression of TLRs in both HCV and HCV/HIV. Liver and peripheral blood mononuclear cells (PBMCs) were obtained from HCV & HCV/HIV-infected patients and PBMCs from HIV-infected patients. Liver RNA was analysed by microarray and reverse transcription quantitative PCR (RT-qPCR). PBMCs were analysed by flow cytometry. Associations with hepatic histology and infection type were sought. Forty-six HCV, 20 HIV and 27 HCV/HIV-infected patients were recruited. Increasing Metavir inflammatory activity score was associated with increased hepatic TLR mRNA by RT-qPCR: TLR2 (P ≤ 0.001), TLR4 (P = 0.008) and TNF-α (P ≤ 0.001). A high degree of correlation was seen between hepatic mRNA expression of TNF-αvs TLR2 (r(2) = 0.66, P < 0.0001) and TLR4 (r(2) = 0.60, P < 0.0001). No differences in TLR gene or protein expression was observed between HCV, HCV/HIV- or HIV-infected groups. Hepatic TLR2, TLR4 and TNF-α mRNA are associated with hepatic inflammation in both HCV and HCV/HIV infection. High correlation between TNF-α and TLR2/TLR4 suggests a role for the innate immune response in TNF-α production. Activation of the innate immune response appears to be independent of infection type.

Characterization of the innate immune signalling pathways in hepatocyte cell lines

Hepatitis B virus (HBV) infection is a major cause of liver-related morbidity and mortality. Toll-like receptors (TLRs) have recently been recognized to play an important role in the pathogenesis of chronic hepatitis B (CH-B). Furthermore, manipulation of TLR signalling pathways shows potential as an antiviral therapeutic strategy. Whether hepatocytes themselves possess intact TLR signalling pathways remains controversial. It is critical that cell culture models be developed to allow investigation of the interaction between HBV and the TLR signalling pathways. We have screened three hepatocyte cell lines for the integrity of pro-inflammatory responses and antiviral cytokines following stimulation with interleukin-1 (IL-1) and different TLR ligands. We observed that Huh-7, HepG2 and PH5CH8 cells selectively responded to IL-1 and TLR2 ligands, leading to the activation of NF-kappaB. In addition, the PH5CH8 cell lines were able to induce type 1 interferon (IFN) via both TLR3 and RIG-I following stimulation with poly I:C, HepG2 cells mounted an IFN response via RIG-I only, whereas Huh-7 cells were unresponsive. We conclude that the hepatocyte cell lines investigated display a repertoire of TLR signalling, albeit limited, suggesting that hepatocytes may themselves play an active role in innate immune responses to viruses such as HBV. Furthermore, particular hepatoma cell lines are suitable for investigating the interaction between HBV and hepatocyte-expressed pattern recognition receptors.

Tooth brushing habits in uninstructed adults--frequency, technique, duration and force

Professional recommendations for individual oral hygiene mostly include tooth brushing at least twice daily for 2-3 min with gentle force using the Bass technique or modifications of it. This study evaluated whether habitual tooth brushing actually meets these standards. Uninstructed adults (n = 103; mean age 31 +/- 6 years; 61 female, 42 male) with habitual manual tooth brushing were given a self-administered questionnaire about the frequency of brushing and a computer system recorded their brushing technique, duration and force. The majority (79.6%) of participants brushed twice daily. The mean brushing duration was 96.6 +/- 36.0 s, the mean brushing force was 2.3 +/- 0.7 N (max. 4.1 N), and no significant differences were found for quadrants. Most subjects (73.8%) brushed with circling, 8.7% with horizontal/scrubbing, 13.6% with horizontal/circling and 3.9% with vertical/sweeping movements. Modified Bass technique was not observed. When appropriate brushing habits were defined as brushing at least twice daily for 120 s with a brushing force of less than 3 N and with circling or vertical sweeping movements, only 25.2% of the participants fulfilled all criteria, emphasising the ongoing need for oral hygiene education.

Suprakondyl�re Extension einer pertrochant�ren Femurfraktur bei einem Patienten mit Unterschenkelamputation

Pertrochanteric femur fracture is rare in patients with lower leg amputation. Using supracondylar traction takes full advantage of the extension table. Intraoperative insertion of a Steinmann pin for traction is a well-known low-risk procedure. In our opinion, this kind of extension is a simple procedure that carries no risks for postoperative prosthetic management in patients with lower leg amputation.

Generation of tumor-associated cytotoxic T lymphocytes requires interleukin 4 from CD8(+) T cells

Activation of tumor-associated CD8(+) cytotoxic T lymphocytes (CTLs) often requires antigen representation, e.g., by dendritic cells (DCs), and CD4(+) T cell help. Previously, we showed that CTL-mediated tumor immunity required interleukin 4 (IL-4) during the immunization but not effector phase. To determine the source and target cells of IL-4, we performed adoptive T cell transfers using CD4(+) and CD8(+) T cells from IL-4(-/-) and IL-4R(-/-) mice and analyzed CTL generation. Even though necessary for CTL generation, CD4(+) T cells did not need to express IL-4 or IL-4R. Surprisingly, CTL generation required IL-4 but not IL-4R expression by CD8(+) T cells. As IL-4 (a) was expressed by naive CD8(+) T cells within 24 h after antigen encounter, (b) IL-4 induced DC maturation, and (c) CTL development was impaired in T cell-reconstituted IL-4R(-/-) mice, CD8(+) T cell-derived IL-4 appears to act on DCs. We conclude that CD4(+) and CD8(+) T cells provide different signals for DC activation during CTL generation.

Tumor rejection by disturbing tumor stroma cell interactions

The stroma of solid tumors is a complex network of different cell types. We analyzed stroma cell interactions in two tumor models during cyclophosphamide (Cy)-induced tumor rejection. In growing tumors, tumor infiltrating macrophages (TIMs) produced interleukin (IL)-10. Beginning 6 h after Cy-treatment T cells in the tumor were inactivated and TIMs switched to interferon (IFN)-gamma production. Both, IL-10 production before and IFN-gamma production after Cy-treatment by TIMs required T cells. With the same kinetics as TIMs started to produce IFN-gamma the tumor vasculature was destroyed which required IFN-gamma receptor expression on host but not tumor cells. These events preceded hemorrhagic necrosis and residual tumor cell elimination by T cells. Together, T cells regulate the function of TIMs and tumor rejection can be induced by disturbing the stroma network.

Vaccination with attenuated simian immunodeficiency virus by DNA inoculation

Delivering attenuated lentivirus vaccines as proviral DNA would be simple and inexpensive. Inoculation of macaques with wild-type simian immunodeficiency virus strain mac239 (SIV(mac239)) DNA or SIV(mac239) DNA containing a single deletion in the 3' nef-long terminal repeat overlap region (nef/LTR) led to sustained SIV infections and AIDS. Injection of SIV(mac239) DNA containing identical deletions in both the 5' LTR and 3' nef/LTR resulted in attenuated SIV infections and substantial protection against subsequent mucosal SIV(mac251) challenge.

Rapid, ATP-dependent degradation of a truncated D1 protein in the chloroplast

The D1 protein constitutes one of the reaction center subunits of photosystem II and turns over rapidly due to photooxidative damage. Here, we studied the degradation of a truncated D1 protein. A plasmid with a precise deletion in the reading frame of the psbA gene encoding D1 was introduced into the chloroplast of Chlamydomonas reinhardtii. A homoplasmic mutant containing the desired gene was able to synthesize the truncated form of the polypeptide, but could not accumulate significant levels of it. As a consequence, other central photosystem II subunits did not assemble within the thylakoid membrane. In vivo pulse-chase experiments showed that the abnormal D1 protein is rapidly degraded in the light. Degradation was delayed in the light in the presence of an uncoupler, or when cells were incubated in the dark. Pulse-chase experiments performed in vitro indicate that an ATP and metal-dependent protease is responsible for the breakdown process. The paper describes the first in vivo and in vitro functional test for ATP-dependent degradation of a defect polypeptide in chloroplasts. The possible involvement of proteases similar to those removing abnormal proteins in prokaryotic organisms is discussed on the basis of proteases recently identified in chloroplasts.

Compound effects of point mutations causing campomelic dysplasia/autosomal sex reversal upon SOX9 structure, nuclear transport, DNA binding, and transcriptional activation

Human mutations in the transcription factor SOX9 cause campomelic dysplasia/autosomal sex reversal. Here we identify and characterize two novel heterozygous mutations, F154L and A158T, that substitute conserved "hydrophobic core" amino acids of the high mobility group domain at positions thought to stabilize SOX9 conformation. Circular dichroism studies indicated that both mutations disrupt alpha-helicity within their high mobility group domain, whereas tertiary structure is essentially maintained as judged by fluorescence spectroscopy. In cultured cells, strictly nuclear localization was observed for wild type SOX9 and the F154L mutant; however, the A158T mutant showed a 2-fold reduction in nuclear import efficiency. Importin-beta was demonstrated to be the nuclear transport receptor recognized by SOX9, with both mutant proteins binding importin-beta with wild type affinity. Whereas DNA bending was unaffected, DNA binding was drastically reduced in both mutants (to 5% of wild type activity in F154L, 17% in A158T). Despite this large effect, transcriptional activation in cultured cells was only reduced to 26% in F154L and 62% in A158T of wild type activity, suggesting that a small loss of SOX9 transactivation activity could be sufficient to disrupt proper regulation of target genes during bone and testis formation. Thus, clinically relevant mutations of SOX9 affect protein structure leading to compound effects of reduced nuclear import and reduced DNA binding, the net effect being loss of transcriptional activation.

The sequence requirements for a functional Escherichia coli replication origin are different for the chromosome and a minichromosome

We have developed a simple three-step method for transferring oriC mutations from plasmids to the Escherichia coli chromosome. Ten oriC mutations were used to replace the wild-type chromosomal origin of a recBCsbcB host by recombination. The mutations were subsequently transferred to a wild-type host by transduction. oriC mutants with a mutated DnaA box R1 were not obtained, suggesting that R1 is essential for chromosomal origin function. The other mutant strains showed the same growth rates, DNA contents and cell mass as wild-type cells. Mutations in the left half of oriC, in DnaA boxes M, R2 or R3 or in the Fis or IHF binding sites caused moderate asynchrony of the initiation of chromosome replication, as measured by flow cytometry. In mutants with a scrambled DnaA box R4 or with a modified distance between DnaA boxes R3 and R4, initiations were severely asynchronous. Except for oriC14 and oriC21, mutated oriCs could not, or could only poorly, support minichromosome replication, whereas most of them supported chromosome replication, showing that the classical definition of a minimal oriC is not valid for chromosome replication. We present evidence that the functionality of certain mutated oriCs is far better on the chromosome than on a minichromosome.

Age-dependent changes in magnetization transfer contrast of white matter in the pediatric brain

BACKGROUND AND PURPOSE

It is unknown to what extent magnetization transfer contrast (MTC) in white matter of the brain changes during myelination. The goal of this study was to measure the age-dependent changes of MTC in different regions of the pediatric brain and to evaluate their relation to T2 relaxation times.

METHODS

Seventy children aged 1 week to 80 months without evidence of organic brain disease underwent MR imaging of the brain. A double-echo spin-echo (SE) sequence and an SE sequence with and without an off-resonance pulse were performed in the axial orientation. Using paired images, we calculated MTC ratios in 13 predefined regions of the brain and compared them with the T2 relaxation times measured in the same areas. Regression analysis was performed for both parameters to evaluate age dependency.

RESULTS

MTC in white matter increased during myelination from a range of 13% to 19% to a range of 34% to 37%. At the same time, T2 relaxation times decreased from a range of 115 to 160 milliseconds to a range of 60 to 70 milliseconds after myelination. For both MTC and T2 relaxation times, age dependency could be expressed by a monoexponential function.

CONCLUSION

A strong positive correlation exists between MTC ratios and the degree of myelination in the pediatric brain, and an inverse correlation exists between MTC and T2 relaxation times. Fast proton relaxation within macromolecules in the myelinated white matter and subsequent MT may be the most important reason for the decreasing T2 relaxation time of white matter during brain myelination.

An aquaporin-like gene required for the Brassica self-incompatibility response

Self-incompatibility in Brassica refers to the rejection of self-related pollen and is mediated by a receptor protein kinase localized to the plasma membrane of the stigma epidermis in the flower. The recessive mutation mod eliminates self-incompatibility in the stigma. In mod mutants, self-compatibility was shown to be associated with the absence of transcripts encoded by an aquaporin-related gene. This observation suggests that a water channel is required for the self-incompatibility response of Brassica, which is consistent with the concept that regulation of water transfer from the stigma to pollen is a checkpoint in the early events of pollination in the crucifer family.

Comminuted humeral head fractures: a multicenter analysis

Three centers' experience with 93 comminuted humeral head fractures were clinically (Constant score) and radiologically (Neer) analyzed. The results revealed fundamental differences between the various types of fractures depending on the number of fragments. For three-part fractures open reduction and internal fixation (mean Constant scores 83 and 91 points, respectively) or conservative treatment (78 points) seem to be indicated. The prognosis for four-part fractures is determined largely by the vascular supply of the head fragment with a high risk of humeral head osteonecrosis. For this reason primary prosthetic replacement (mean Constant score, 74 points compared with 54 points for conservative treatment and 52 points for open reduction) should be recommended for this type of fracture. In conclusion, we stress the importance of fracture type directing the therapeutic modality.

Light-induced biogenesis of the light-harvesting complexes of Photosystems I and II : Gene expression and protein accumulation

The light-harvesting complexes of Photosystems I and II contain multiple chlorophyll-carotenoid-binding proteins. The stoichiometry and topology of the LHCs is precisely defined to optimally funnel captured light energy to the reaction center. The manner in which this exact arrangement is accomplished is not known. As an initial means to understand the mechanisms involved in establishing a functional LHC, the influence of light on LHC gene expression and protein accumulation was studied during the light-induced greening of etiolated wild type and chlorophyll b-less mutant barley seedlings. Light, involving phytochrome, promotes the expression of all LHC genes with the same relative kinetics. LHC protein accumulation closely parallels the increases observed in transcript levels. Differential accumulation of LHC transcripts or protein was not evident in wild type seedlings. Post-translational factors are likely to be involved in fine tuning the position and stoichiometry of the individual LHCs around the reaction center.

Stability of the Apoproteins of Light-Harvesting Complex I and II during Biogenesis of Thylakoids in the Chlorophyll b-less Barley Mutant Chlorina f2

Transcription and translation of Lhc (cab) genes have been compared in the chlorina f2 mutant of barley (Hordeum vulgare) and its wild type to study the effect of chlorophyll b's absence on the regulation of assembly of the light-harvesting complexes (LHC). All tested genes were transcribed and the amount of their respective mRNAs increased rhythmically upon illumination of etiolated mutant plants. The synthesis of individual LHC apoproteins also had a rhythmic pattern when total leaf protein extracts were examined, whereas they increased gradually in the thylakoid. Only some LHC pigment-proteins present in wild-type thylakoids were found in mature mutant membranes. Thus, only the 25-kD (type 3) apoprotein of the three apoproteins of the major LHC IIb complex survived. The amount of the minor LHC II pigment-proteins was considerably reduced but not to zero. Photosystem I had some of the two LHC la apoproteins but had little of those of LHC lb. This was reflected in a shift of the 77-K emission maximum of whole leaves from 741 to 732 nm. It is concluded that the two largest LHC IIb and the LHC Ib apoproteins need chlorophyll b for stable integration into the membrane and that posttranslational regulation plays a major role in LHC assembly.