793 research outputs found

    Dynamic Posterior Instability Test: A New Test for Posterior Glenohumeral Instability

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    BACKGROUND: Recurrent posterior shoulder instability has become an increasingly recognized cause of shoulder disability, especially among athletes. The presentation can be vague and therefore its clinical diagnosis is often overlooked. Few diagnostic tests exist and these tests are difficult to perform in an anxious and apprehensive patient. Many also lack high specificity and do not effectively distinguish posterior labral tears from other shoulder pathologies. As a result, the authors worked to develop a new test, the dynamic posterior instability test (DPIT). The purpose of this study was to describe the DPIT as well as a modified DPIT test and to evaluate the accuracy of these tests in detecting posterior labral pathology. It was hypothesized that the dynamic posterior instability test (DPIT) would improve accuracy in the evaluation of posterior labral tears. METHODS: For a 9-month period, the DPIT and modified DPIT tests were performed on all patients evaluated for posterior instability of the shoulder. The records of all patients who had undergone a posterior labral repair (type VIII SLAP and posterior labral tears) were reviewed. The results of the DPIT and modified DPIT tests were compared to intra-operative findings. Anterior glenohumeral instability patients were also evaluated with these tests to serve as a control. RESULTS: Fifty-one patients had a positive and 3 patients had a negative DPIT test. Of the anterior instability patients, there was 1 positive and 19 negative test results. The sensitivity of the DPIT test was 94.4%, specificity 95%, the positive predictive value 0.98, and the negative predictive value 0.86. The results of the modified DPIT were the same as the DPIT test. CONCLUSIONS: The DPIT and modified DPIT tests provide a valuable new tool when combined with history and other physical examination findings improve the accuracy of diagnosis of posterior shoulder instability

    Fragment-based discovery of a regulatory site in thioredoxin glutathione reductase acting as "doorstop" for NADPH entry

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    Members of the FAD/NAD-linked reductase family are recognized as crucial targets in drug development for cancers, inflammatory disorders, and infectious diseases. However, individual FAD/NAD reductases are difficult to inhibit in a selective manner with off target inhibition reducing usefulness of identified compounds. Thioredoxin glutathione reductase (TGR), a high molecular weight thioredoxin reductase-like enzyme, has emerged as a promising drug target for the treatment of schistosomiasis, a parasitosis afflicting more than 200 million people. Taking advantage of small molecules selected from a high-throughput screen and using X-ray crystallography, functional assays, and docking studies, we identify a critical secondary site of the enzyme. Compounds binding at this site interfere with well-known and conserved conformational changes associated with NADPH reduction, acting as a doorstop for cofactor entry. They selectivity inhibit TGR from Schistosoma mansoni and are active against parasites in culture. Since many members of the FAD/NAD-linked reductase family have similar catalytic mechanisms the unique mechanism of inhibition identified in this study for TGR broadly opens new routes to selectively inhibit homologous enzymes of central importance in numerous diseases

    Cisplatin and Oxaliplatin Toxicity: Importance of Cochlear Kinetics as a Determinant for Ototoxicity

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    Background Cisplatin is a commonly used platinum anti-cancer drug. Regrettably cisplatin has dose-limiting ototoxic side effects, e.g. the drug can induce an irreversible hearing loss. The ototoxic mechanisms of cisplatin have not been elucidated in the human ear and no clinically useful oto-protectors are yet available. Cisplatin is a necessary part of many treatment regimes. Its beneficial therapeutic effects might be reduced if cisplatin was excluded from the treatment in order to protect the hearing function. In this work the ototoxic effects of cisplatin are studied with the aim to better understand the mechanisms behind the irreversible hearing loss induced by this drug. Oxaliplatin is a second generation platinum-derivative anti-cancer drug, free from ototoxic side effects in clinical practice. The effects of oxaliplatin on the inner ear have been studied in this work and the results are compared with cisplatin treatment. The two drugs differ regarding both anti-cancer effects and side effects, which could be attributed to differences in pharmacokinetic factors, cellular uptake and apoptotic mechanisms. The thioredoxin redox system with the enzyme thioredoxin reductase (TrxR) was studied in cochleae due to a suggested DNA-independent apoptotic mechanism of the hair cells. The cochlear pharmacokinetics of cisplatin was assessed and the transport protein organic cation transporter 2 (OCT2) was studied in relation to the ototoxic effect of cisplatin. Material and methods Cultured human colon carcinoma cells and cell cultures of rat organ of Corti were used for apoptosis studies in vitro following exposure to cisplatin and oxaliplatin. Cisplatin and oxaliplatin were administered i.v. to guinea pigs, followed by in vivo sampling of blood, cerebrospinal fluid (CSF) and scala tympani (ST) perilymph. Liquid chromatography with post-column derivatization was used to determine the concentration of parent drug in the samples. Electrophysiological hearing thresholds and the loss of hair cells were assessed to evaluate their ototoxic effects. Phenformin, a potential blocker of OCT2 was administered and the ototoxic side effect of cisplatin was evaluated. For immunohistochemical studies, cochlea from rat, guinea pig and pig were used, where TrxR and OCT2 were evaluated in the cochlea. TrxR-assays were used to measure the TrxR activity in cochlear tissue, both in vivo and in vitro. Results The results from the in vitro studies showed that addition of either cisplatin or oxaliplatin to the culture medium in organ of Corti cell cultures caused a similar amount of outer hair cell loss and inhibition of TrxR activity. Cisplatin exposure to cultured human colon carcinoma cells also reduced the activity of TrxR. The results from the in vivo studies showed that a considerable concentration of cisplatin was present in ST perilymph as compared with weak concentrations of oxaliplatin after high dose oxaliplatin i.v. Ten minutes after cisplatin administration, its concentration in ST perilymph was 4-fold higher in the basal turn of the cochlea as compared to the apex. Cisplatin could be analysed in ST perilymph for up to 120 min. Phenformin i.v. did not reduce the ototoxic side-effect of cisplatin. Positive immunoreactivity to TrxR was evident in both hair cells and spiral ganglion cells. Futhermore, OCT2 was expressed in the supporting cells of organ of Corti and in the spiral ganglion cells. Conclusion The transport of cisplatin to the vulnerable cells of hearing seems to be of major importance for the ototoxic effects. An early high concentration of cisplatin in the base of the cochlea and delayed elimination of cisplatin from ST perilymph may be related to the cisplatin-induced loss of outer hair cells in the basal turn of the cochlea. Cisplatin and oxaliplatin both cause similar ototoxic effects when the organ of Corti is directly exposed in vitro. The thioredoxin redox system with the TrxR enzyme may well play a critical role in cisplatininduced ototoxicity. The presence of OCT2 in the supporting cells indicates that this transport protein is primarily not involved in the uptake of cisplatin from the systemic circulation but rather from the deeper compartments of the cochlea. The knowledge elicited in this work will hopefully suggest objectives for further studies in order to develop oto-protective treatments to preserve the hearing of cisplatin treated patients

    Hypoxia Sensitive Metal β-Ketoiminate Complexes Showing Induced Single Strand DNA Breaks and Cancer Cell Death by Apoptosis

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    A series of ruthenium and iridium complexes have been synthesised and characterised with 20 novel crystal structures discussed. The library of β-ketoiminate complexes has been shown to be active against MCF-7 (human breast carcino-ma), HT-29 (human colon carcinoma), A2780 (human ovarian carcinoma) and A2780cis (cisplatin resistant human ovarian carcinoma) cell lines, with selected complexes being more than three times as active as cisplatin against the A2780cis cell line. Complexes have also been shown to be highly active under hypoxic conditions, with the activities of some complexes increasing with a decrease in O2 concentration. The enzyme thioredoxin reductase is over-expressed in cancer cells and complexes reported herein have the advantage of inhibiting this enzyme, with IC50 values measured in the nanomolar range. The anti-cancer activity of these complexes was further investigated to determine whether activity is due to effects on cellular growth or cell survival. The complexes were found to induce significant cancer cell death by apoptosis with levels induced correlating closely with activity in chemosensitivity studies. As a possible cause of cell death, the ability of the complexes to induce damage to cellular DNA was also assessed. The complexes failed to induce double strand DNA break or DNA crosslinking but induced significant levels of single DNA strand breaks indi-cating a different mechanism of action to cisplatin

    Environment change, economy change and reducing conflict at source

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    At a time when fossil fuel burning, nationalism, ethnic and religious intolerance, and other retrograde steps are being promoted, the prospects for world peace and environmental systems stability may appear dim. Yet now is it the more important to continue to examine the sources of conflict. A major obstacle to general progress is the currently dominant economic practice and theory, which is here called the economy-as-usual, or economics-as-usual, as appropriate. A special obstacle to constructive change is the language in which economic matters are usually discussed. This language is narrow, conservative, technical and often obscure. The rapid changes in the environment (physical and living) are largely kept in a separate compartment. If, however, the partition is removed, economics -as-usual, with its dependence on growth and its widening inequality, is seen to be unsustainable. Radical economic change, for better or worse, is to be expected. Such change is here called economy change. The change could be for the better if it involved an expansion of the concept of economics itself, along the lines of oikonomia, a modern revival of a classical Greek term for management or household. In such an expanded view, not everything of economic value can be measured. It is argued that economics-as-usual is the source of much strife. Some features are indicated of a less conflictual economy - more just, cooperative and peaceful. These features include a dignified life available to all people as of right, the word 'wealth' being reconnected with weal, well and well-being, and 'work' being understood as including all useful activity

    Use of manual and powered wheelchair in children with cerebral palsy: a cross-sectional study

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    <p>Abstract</p> <p>Background</p> <p>Mobility is important for the cognitive and psychosocial development of children. Almost one third of children with cerebral palsy (CP) are non-ambulant. Wheelchairs can provide independent mobility, allowing them to explore their environment. Independent mobility is vital for activity and participation and reduces the dependence on caregivers. The purpose of this study was to describe the use of manual and powered wheelchair indoors and outdoors in relation to the degree of independent wheelchair mobility or need for assistance in a total population of children with CP.</p> <p>Methods</p> <p>A cross-sectional study was performed including all children aged 3-18 years with CP living in southern Sweden during 2008. Data was extracted from a register and health care programme for children with CP (CPUP). There were a total of 562 children (326 boys, 236 girls) in the register. Information on the child's use of manual and powered wheelchair indoors and outdoors and the performance in self-propelling or need for assistance were analysed related to age, CP subtype and gross motor function.</p> <p>Results</p> <p>Wheelchairs for mobility indoors were used by 165 (29%) of the 562 children; 61 used wheelchair for independent mobility (32 using manual only, 12 powered only, 17 both) and 104 were pushed by an adult. For outdoor mobility wheelchairs were used by 228 children (41%); 66 used a wheelchair for independent mobility (18 using manual only, 36 powered only, 12 both) and 162 were pushed. The use of wheelchair increased with age and was most frequent in the spastic bilateral and dyskinetic subtypes. Most powered wheelchairs were operated by children at GMFCS level IV.</p> <p>Conclusion</p> <p>In this total population of children with CP, aged 3-18 years, 29% used a wheelchair indoors and 41% outdoors. A majority using manual wheelchairs needed adult assistance (86%) while powered wheelchairs provided independent mobility in most cases (86%). To achieve a high level of independent mobility, both manual and powered wheelchairs should be considered at an early age for children with impaired walking ability.</p

    Serum Progranulin Concentrations May Be Associated With Macrophage Infiltration Into Omental Adipose Tissue

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    OBJECTIVE—Progranulin is an important molecule in inflammatory response. Chronic inflammation is frequently associated with central obesity and associated disturbances; however, the role of circulating progranulin in human obesity, type 2 diabetes, and dyslipidemia is unknown
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