Telomere length and telomerase activity in malignant lymphomas at diagnosis and relapse

Telomere length maintenance, in the vast majority of cases executed by telomerase, is a prerequisite for long-term proliferation. Most malignant tumours, including lymphomas, are telomerase-positive and this activity is a potential target for future therapeutic interventions since inhibition of telomerase has been shown to result in telomere shortening and cell death in vitro. One prerequisite for the suitability of anti-telomerase drugs in treating cancer is that tumours exhibit shortened telomeres compared to telomerase-positive stem cells. A scenario is envisioned where the tumour burden is reduced using conventional therapy whereafter remaining tumour cells are treated with telomerase inhibitors. In evaluating the realism of such an approach it is essential to know the effects on telomere status by traditional therapeutic regimens. We have studied the telomere lengths in 47 diagnostic lymphomas and a significant telomere shortening was observed compared to benign lymphoid tissues. In addition, telomere length and telomerase activity were studied in consecutive samples from patients with relapsing non-Hodgkin's lymphomas. Shortened, unchanged and elongated telomere lengths were observed in the relapse samples. The telomere length alterations found in the relapsing lymphomas appeared to be independent of telomerase and rather represented clonal selection random at the telomere length level. These data indicate that anti-telomerase therapy would be suitable in only a fraction of malignant lymphomas. © 2000 Cancer Research Campaig

Comparing human and automatic speech recognition in a perceptual restoration experiment

Speech that has been distorted by introducing spectral or temporal gaps is still perceived as continuous and complete by human listeners, so long as the gaps are filled with additive noise of sufficient intensity. When such perceptual restoration occurs, the speech is also more intelligible compared to the case in which noise has not been added in the gaps. This observation has motivated so-called 'missing data' systems for automatic speech recognition (ASR), but there have been few attempts to determine whether such systems are a good model of perceptual restoration in human listeners. Accordingly, the current paper evaluates missing data ASR in a perceptual restoration task. We evaluated two systems that use a new approach to bounded marginalisation in the cepstral domain, and a bounded conditional mean imputation method. Both methods model available speech information as a clean-speech posterior distribution that is subsequently passed to an ASR system. The proposed missing data ASR systems were evaluated using distorted speech, in which spectro-temporal gaps were optionally filled with additive noise. Speech recognition performance of the proposed systems was compared against a baseline ASR system, and with human speech recognition performance on the same task. We conclude that missing data methods improve speech recognition performance in a manner that is consistent with perceptual restoration in human listeners

Oppituntien aikainen liikunta alakoulussa:miten liikunta edistää oppimista?

Tiivistelmä. Tutkielman tarkoituksena oli selvittää, millainen oppituntien aikainen liikunta tukee alakouluikäisten oppimista. Useissa lasten liikunnan määrää mittaavissa tutkimuksissa on käynyt ilmi, etteivät lapset liiku kehityksensä kannalta riittävästi. Tämän vuoksi kouluissa pyritään yhä enemmän liikuttamaan lapsia koulupäivän aikana, ja liikuntaa on lisätty oppitunneille esimerkiksi opetukseen integroidun liikunnan ja taukoliikunnan avulla. Aihe on tärkeä ja ajankohtainen, sillä koronapandemian myötä lasten fyysisen aktiivisuuden määrä on vähentynyt ja luonut haasteita lasten liikkumiselle. Tutkimuksista on kuitenkin saatu selkeää näyttöä siitä, että oppituntien aikainen liikunta tukee koulumenestystä etenkin matematiikan ja äidinkielen osalta. Liikunnan ja oppimisen välisen tutkimusalueen ollessa kuitenkin suhteellisen nuori, tarvitaan laadukasta tutkimusta lisää tarkempien johtopäätösten saamiseksi myös muiden oppiaineiden osalta. Keskeisimmät tutkimustulokset oppitunnin aikaisen liikunnan ja koulumenestyksen väliseen yhteyteen liittyvät fyysisen aktiivisuuden kestoon, voimakkuuteen sekä motoristen taitojen harjoittelemiseen. Tutkimusten mukaan kohtalainen ja voimakkaasti kuormittava fyysinen aktiivisuus olivat yhteydessä parempaan koulumenestykseen ja luokkahuonekäyttäytymiseen. Koulumenestys, matematiikan ja lukemisen arvosanat, luokkahuonekäyttäytyminen sekä tehtäviin keskittyminen ovat tutkimusten mukaan parantuneet, kun opetukseen on integroitu 5–20 minuuttia kestävää fyysistä aktiivisuutta tai liikuntaa sisältäviä taukoja. Tutkielman perusteella voidaan tehdä se johtopäätös, että oppitunneilla tulisi hyödyntää liikuntaa ja fyysistä aktiivisuutta joko fyysisesti aktiivisten taukojen tai opetukseen integroidun liikunnan avulla. Fyysisessä aktiivisuudessa tulisi kiinnittää huomiota siihen, että se olisi kohtalaisesti tai voimakkaasti kuormittavaa, ja samalla tulisi vähentää istumisen ja paikallaanolon määrää. Ammattitaitoisen opettajan tulisi hyödyntää monipuolista liikuntaa osana opetusta, sillä liikunnan avulla oppilaiden motoriset taidot ja koulumenestys voivat parantua

Intraoperative Complications and Mid-Term Follow-Up of Large-Diameter Head Metal-on-Metal Total Hip Arthroplasty and Hip Resurfacing Arthroplasty

Background and Aims: Large-diameter head total hip arthroplasty and hip resurfacing arthroplasty were popular in Finland from 2000 to 2012 for the treatment of hip osteoarthritis. The aim of this retrospective study was to investigate the mid-term survival of large-diameter head total hip arthroplasty patients operated on in three university hospitals and to compare these results to the survival of hip resurfacing arthroplasty patients. Material and Methods: A total of 3860 hip arthroplasties (3029 large-diameter head total hip arthroplasties in 2734 patients and 831 hip resurfacing arthroplasties in 757 patients) were operated on between January 2004 and December 2009. The mean follow-up was 4.3years (range: 0.3-8.0years) in the total hip arthroplasty group and 5.1years (range: 1.7-7.9years) in the hip resurfacing arthroplasty group. Cox multiple regression model and Kaplan-Meier survival analysis were used to study the survival of the total hip arthroplasties and the hip resurfacing arthroplasties. Intraoperative complications and reasons for revisions were also evaluated. Results: In Cox regression analysis, the hazard ratio for revision of hip resurfacing arthroplasty was 1.5 compared with large-diameter head total hip arthroplasty (95% confidence interval: 1.0-2.2) (p=0.029). The cumulative Kaplan-Meier survival rate was 90.7% at 7.7years for the large-diameter head total hip arthroplasty (95% confidence interval: 86.8-94.6) and 92.2% at 7.6years for hip resurfacing arthroplasty (95% confidence interval: 89.9-94.6). There were a total of 166/3029 (5.5%) intraoperative complications in the large-diameter head total hip arthroplasty group and 20/831 (2.4%) in the hip resurfacing arthroplasty group (p=0.001). Revision for any reason was performed on 137/3029 (4.5%) of the arthroplasties in the large-diameter head total hip arthroplasty group and 52/831 (6.3%) in the hip resurfacing arthroplasty group (p=0.04). Conclusion: The mid-term survival of both of these devices was poor, and revisions due to adverse reactions to metal debris will most likely rise at longer follow-up. There were more intraoperative complications in the large-diameter head total hip arthroplasty group than in the hip resurfacing arthroplasty group.Peer reviewe