11 research outputs found

    Productivity of authors in the field of diabetes: bibliographic analysis of trial publications

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    To determine whether trial publications of glucose lowering drugs are dominated by a small group of highly prolific authors ("supertrialists") and to identify some of their characteristics. Bibliographic analysis of trial publications. We searched PubMed for all randomised controlled trials (RCTs) relating to glucose lowering drugs published between 1 January 1993 and 31 December 2013. From these publications we identified the 110 most prolific authors using PubReMiner. The 991 RCTs they published were examined for various characteristics such as author number, commercial sponsorship, company authorship, conflicts of interest, etc. The track record of the top 11 authors was studied in more detail. Proportion of articles published by the top 110 and the top 11 authors. 3782 articles from 13,592 authors were identified. The top 110 authors were named in 1227 (32.4%) of all articles, and the top 11 authors in 397 (10.5%) of all articles. The top 110 authors published 991 RCTs for a median of 20 (range 4-77) RCTs per author; the top 11 published 354 RCTs for a median of 42 (36-77) RCTs per author. Of the 110 top authors, 48 were employed by a pharmaceutical company. Of the 991 RCTs, 906 were commercially sponsored. Of 704 articles that could be assessed for conflicts of interest, only 42 (6%) were considered fully independent. Medical writing assistance was acknowledged in 439 (44.3%) of 991 RCTs. The past two decades have seen an explosive increase in the number of published clinical trials regarding glucose lowering treatment. Some authors have made a disproportionate contribution to the therapeutic evidence base; one third of the RCT evidence base on glucose lowering drug treatment for diabetes was generated by <: 1% of authors. Of these, 44% were company employees and 56% were academics who work closely with the pharmaceutical companie

    Orchidopexy for bilateral undescended testes : a multicentre study on its effects on fertility and comparison of two fixation techniques

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    To evaluate fertility potential after orchidopexy for bilateral undescended testis and compare two surgical fixation techniques for effect on fertility. Men older than 22 years who had either tunica albuginea orchidopexy (TAO) or “no-touch” technique (NTO) in childhood for bilateral undescended testis (BUDT) were selected. Participants filled out a questionnaire followed by physical examination, had testicular ultrasound, blood sample and semen analysis. Statistical testing was performed using general linear modelling. Sixty-seven out of 166 individuals responded. Forty-nine completed the questionnaire, and nine (18.3%) reported having fathered children. Thirty-six showed up for further examination, 26 had TAO and 10 NTO. Impaired hormonal spermatogenesis regulation (34.6% vs. 20%), higher subfertility rate (46% vs. 20%) and lower means of motile spermatozoa (58.1 × 106 spz vs. 177.9 × 106 spz) were observed in the TAO versus the NTO group; none of these were statistically significant. Four (15.4%) of the TAO and two (20%) of the NTO group have azoospermia. Although the operation technique did not have a significant impact on fertility, unfavourable outcomes were more common after surgery involving the tunica albuginea of the testis. Larger sample sizes are needed to ascertain whether the trends favouring the NTO technique are of any significance

    Orchidopexy for bilateral undescended testes: A multicentre study on its effects on fertility and comparison of two fixation techniques

    No full text
    To evaluate fertility potential after orchidopexy for bilateral undescended testis and compare two surgical fixation techniques for effect on fertility. Men older than 22 years who had either tunica albuginea orchidopexy (TAO) or “no-touch” technique (NTO) in childhood for bilateral undescended testis (BUDT) were selected. Participants filled out a questionnaire followed by physical examination, had testicular ultrasound, blood sample and semen analysis. Statistical testing was performed using general linear modelling. Sixty-seven out of 166 individuals responded. Forty-nine completed the questionnaire, and nine (18.3%) reported having fathered children. Thirty-six showed up for further examination, 26 had TAO and 10 NTO. Impaired hormonal spermatogenesis regulation (34.6% vs. 20%), higher subfertility rate (46% vs. 20%) and lower means of motile spermatozoa (58.1 × 106 spz vs. 177.9 × 106 spz) were observed in the TAO versus the NTO group; none of these were statistically significant. Four (15.4%) of the TAO and two (20%) of the NTO group have azoospermia. Although the operation technique did not have a significant impact on fertility, unfavourable outcomes were more common after surgery involving the tunica albuginea of the testis. Larger sample sizes are needed to ascertain whether the trends favouring the NTO technique are of any significance

    The Natural Course of Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis, and Mycoplasma genitalium in Pregnant and Post-Delivery Women in Pemba Island, Tanzania

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    This study aimed to determine the persistence of Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), Trichomonas vaginalis (TV) and Mycoplasma genitalium (MG) infections during pregnancy and after delivery in vaginal swabs of women from Pemba Island, Tanzania. In the context of an earlier biobanking effort, vaginal swabs were collected at two timepoints during pregnancy and once post-delivery. Detection of CT, NG, TV, and MG was performed by PCR using validated detection kits in samples from 441 pregnant women aged 16–48 years old. Among those, 202 samples were matched during pregnancy and 38 at the second timepoint of the pregnancy and post-delivery CT infection persistence during pregnancy was 100% (n = 11) after an average of eight weeks, that of TV infection 82% (n = 11) after ten weeks, and that of MG infection 75% (n = 4) after ten weeks. Post-delivery (after approximately 22 weeks) infection persistence was 100% for CT (n = 1) and 20% for TV (n = 5). NG was only detected at the last collection timepoint, its persistence rate could not be determined. These results show persistence and clearance of curable infections during and after pregnancy. Analysis of biobanked samples is a valuable approach in the investigation of the natural history of curable pathogens

    Development of the testis in pre-pubertal boys with cancer after biopsy for fertility preservation

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    STUDY QUESTION: Is testicular growth affected by a testicular biopsy intended for fertility preservation in pre-pubertal boys with cancer? SUMMARY ANSWER: Testicular growth of the biopsied testis is not impeded in comparison to the non-biopsied contralateral testis up until 1 year after surgery. WHAT IS KNOWN ALREADY: Fertility preservation in pre-pubertal boys by means of testicular biopsy has been conducted for more than 15 years. Although immediate adverse effects of testicular biopsy are rare (1%), no data exist on the effect of biopsy on testicular growth. STUDY DESIGN, SIZE, DURATION: In this prospective cohort study, between March 2011 and February 2017, 93 parents of prepubertal boys were offered cryopreservation of testicular tissue of their son, of whom 78 consented. Sixty-four boys were included in this follow-up study. PARTICIPANTS/MATERIALS, SETTING, METHODS: All boys with cancer at the paediatric oncology department of the Academic Medical Center (AMC) who needed gonadotoxic therapy and were unable to ejaculate were offered cryopreservation of testicular tissue prior to treatment. By testicular ultrasound before and after biopsy (1, 6 and 12 months after biopsy), volume and parenchymal abnormalities were assessed. Data were analysed using mixed-effects modelling. MAIN RESULTS AND THE ROLE OF CHANCE: Of the 64 included boys all were followed up at 1 month, 58 at 6 months and 55 at 12 months. Mean testicular volumes after 1, 6 and 12 months after biopsy were 1.7 +/- 2.1, 1.7 +/- 2.2 and 1.9 +/- 2.4 for the biopsied testis and 1.8 +/- 2.2, 1.8 +/- 2.3 and 2.0 +/- 2.2 for the non-biopsied testis, respectively. Biopsy of the testis did not have a significant impact on testicular growth. Immediate adverse effects of the biopsy, i.e. wound infections, were seen in 3/78 boys (3.8%). LIMITATIONS, REASONS FOR CAUTION: Although it is the largest cohort available to date, the number of patients included in our follow-up is still relatively small. A larger cohort would be able to evaluate growth more precisely. Follow-up was discontinued in a significant portion of boys, 12/76 (15.8%), mainly because of death due to primary illness but also because they could not be reached or declined further follow-up. WIDER IMPLICATIONS OF THE FINDINGS: These reassuring data may be used in counselling future boys who are eligible for fertility preservation and their parent

    Cryostorage of testicular tissue and retransplantation of spermatogonial stem cells in the infertile male.

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    Transplantation of own cryostored spermatogonial stem cells (SSCs) is a promising technique for fertility restoration when the SSC pool has been depleted. In this regard, cryopreservation of pre-pubertal testicular tissue or SSCs suspensions before gonadotoxic therapies is ethically accepted and increasingly proposed. SSC transplantation has also been considered to treat other causes of infertility relying on the possibility of propagating SSCs retrieved in the testes of infertile men before autologous re-transplantation. Although encouraging results were achieved in animals and in preclinical experiments, clinical perspectives are still limited by a number of unresolved technical and safety issues, such as the risk of cancer cell contamination of cells intended for transplantation and the genetic and epigenetic stability of SCCs when cultured before re-transplantation. Moreover, while genome editing techniques raise the hope of modifying the SSCs genome before re-transplantation, their application for reproductive purposes might be a step too far for the moment
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