Thomas Karmark Dreyer

Dr. Thomas Karmark Dreyer

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Research Focus & Metrics

Academic Career Length

13Years (2014-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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6 April 2020 in Cancers
Verified
Journal Article
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NVNinna Voss
Ninna Voss
TDThomas Karmark Dreyer
Thomas Karmark Dreyer
MHMikkel B. Henningsen
Mikkel B. Henningsen
PVPernille Vahl
Pernille Vahl
Bent HonoréBent Honoré
Bent Honoré
EBEbbe Boedtkjer
Ebbe Boedtkjer
The acidic tumor microenvironment modifies malignant cell behavior. Here, we study consequences of the microenvironment in breast carcinomas. Beginning at carcinogen-based breast cancer induction, we supply either regular or NaHCO3-containing drinking water to female C57BL/6j mice. We evaluate urine and blood acid-base status, tumor metabolism (microdialysis sampling), and tumor pH (pH-sensitive microelectrodes) in vivo. Based on freshly isolated epithelial organoids from breast carcinomas and normal breast tissue, we assess protein expression (immunoblotting, mass spectrometry), intracellular pH (fluorescence microscopy), and cell proliferation (bromodeoxyuridine incorporation). Oral NaHCO3 therapy increases breast tumor pH in vivo from 6.68 ± 0.04 to 7.04 ± 0.09 and intracellular pH in breast epithelial organoids by ~0.15. Breast tumors develop with median latency of 85.5 ± 8.2 days in NaHCO3-treated mice vs. 82 ± 7.5 days in control mice. Oral NaHCO3 therapy does not affect tumor growth, histopathology or glycolytic metabolism. The capacity for cellular net acid extrusion is increased in NaHCO3-treated mice and correlates negatively with breast tumor latency. Oral NaHCO3 therapy elevates proliferative activity in organoids from breast carcinomas. Changes in protein expression patterns—observed by high-throughput proteomics analyses—between cancer and normal breast tissue and in response to oral NaHCO3 therapy reveal complex influences on metabolism, cytoskeleton, cell-cell and cell-matrix interaction, and cell signaling pathways. We conclude that oral NaHCO3 therapy neutralizes the microenvironment of breast carcinomas, elevates the cellular net acid extrusion capacity, and accelerates proliferation without net effect on breast cancer development or tumor growth. We demonstrate unexpected pro-neoplastic consequences of oral NaHCO3 therapy that in breast tissue cancel out previously reported anti-neoplastic effects.

17 April 2023 in Cancers
Verified
Journal Article
Open access
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NANessn Azawi
Nessn Azawi
JVJuan Luis Vásquez
Juan Luis Vásquez
TDThomas Karmark Dreyer
Thomas Karmark Dreyer
CGCathrine Silberg Guldhammer
Cathrine Silberg Guldhammer
RARami Muthanna Saber Al-Juboori
Rami Muthanna Saber Al-Juboori
Jørgen Bjerggaard JensenJørgen Bjerggaard Jensen
Jørgen Bjerggaard Jensen
Background: The surveillance of non-muscle invasive bladder cancer (NMIBC) requires frequent cystoscopies, which are costly and uncomfortable for patients. Uromonitor is a validated non-invasive urinary test for detecting NMIBC recurrence. However, data on its clinical benefit in an NMIBC surveillance program is limited. Objective: To assess the diagnostic accuracy of Uromonitor in NMIBC surveillance and its potential to limit the number of cystoscopies. Design, Setting, and Participants: The study included 202 patients with previous low-grade (LG) NMIBC tumors. Newly diagnosed patients were scheduled for flexible cystoscopy and Uromonitor test at 4, 12, and 24 months from the time of diagnosis. Patients with tumors diagnosed before entering the study underwent cystoscopy and Uromonitor test at the start of the study and 12 and 24 months from inclusion in the study. Outcome Measurements and Statistical Analysis: Sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV). Results and Limitations: Between February 2020 and October 2022, 202 patients were enrolled in the study. Of these patients, 171 met the eligibility criteria to perform the analysis, with a median age of 69 years, IQR (62–74), and 380 flexible cystoscopies with simultaneous Uromonitor tests. Overall, 39/171 (22.8%) patients had recurrences. Uromonitor showed a sensitivity of 89.7%, specificity of 96.2%, PPV of 72.9%, and NPV of 98.8%. In 28 cases, flexible cystoscopy was falsely positive, leading to surgery, where Uromonitor showed negative results. There were 13 cases of possible false positives for Uromonitor where flexible cystoscopy was negative. Conclusions: Uromonitor displays high diagnostic accuracy in detecting NMIBC recurrence with the potential for reducing the number of flexible cystoscopies in the follow-up of low- and intermediate-risk NMIBC. Patient Summary: We followed up on newly and previously diagnosed patients with LG NMIBC. We concluded that Uromonitor could potentially reduce the number of cystoscopies in NMIBC surveillance programs.

28 January 2023 in Scandinavian Journal of Urology
Verified
Journal Article
Closed access
MDMikkel Deutch
Mikkel Deutch
TDThomas Karmark Dreyer
Thomas Karmark Dreyer
TPTau Pelant
Tau Pelant
Jørgen Bjerggaard JensenJørgen Bjerggaard Jensen
Jørgen Bjerggaard Jensen
Partial nephrectomy is the gold standard treatment in small renal tumours. During partial nephrectomy, the renal artery is clamped which creates transient ischemia. This can damage nephrons and may...

29 November 2023 in Journal of Pediatric Urology
Verified
Journal Article
Open access
CSChristine Sommer
Christine Sommer
TDThomas Karmark Dreyer
Thomas Karmark Dreyer
AEAndreas Ernst
Andreas Ernst
YRYazan F. Rawashdeh
Yazan F. Rawashdeh
Surgical correction of hypospadias aims to achieve normal functionality and appearance. This entails foreskin reconstruction (FR) in countries where the uncircumcised penis constitutes the norm. Long-term data are however scarce. To investigate the long-term outcome of FR in cohort of patients operated for distal hypospadias combined with approximately 20 years after surgery. The hospital management system was searched for patients operated for distal hypospadias in conjunction with FR between 1997 and 2004. Prospective participants were invited to participate in an online questionnaire. Signed consent allowed for extended medical chart review, with regards to hypospadias grade, surgical procedure and complications. Response rate of 44.6 %. For 113 participants, median age at primary surgery was 5.2 (1.0-15.5) years. Two-thirds had a distal meatus while the remaining, meatus was mid to distal shaft. Urethroplasties performed were mainly glanular approximation procedures and meatal based flap procedures in 85 %. Foreskin fistula developed in 15 % of cases. There was no significant relationship between urethroplasty procedure or meatal position and risk of foreskin complications. Three layer closure of foreskin resulted in significantly less complications than two layer closure. Twenty years on 95 % of the men still had an intact foreskin, of whom 16.8 % had received treatment for phimosis. Foreskin was retractable in 92.5 % and 74.7 % in the flaccid and erect states respectively. Ninety intact men had had their sexual debut and in those 23.3 % reported foreskin related issues with intercourse. Evolution of foreskin retractability can be seen in the figure. Current results show that three layer FR in conjunction with hypospadias surgery is feasible and that short-term complication rates were comparable with what has previously been published in the literature. Long-term results indicate that FR is durable with regards to anatomical reconstruction however foreskin function especially in relation to sexual function was compromised in about 25 %. Foreskin retractability after surgery predicted retractability in adulthood for the flaccid but not erect penis. Limitations of this study include the retrospective nature of data collection, and that the questionnaire used was not validated. We however achieved a decent response rate and were able to capture important long-term data. FR has an acceptable complication rate. Long-term results two decades on are remarkably durable with regards to the anatomical preservation of the prepuce, however functionality was compromised with regards to retractability and sexual function in approximately 25 %.

16 December 2021 in Scandinavian Journal of Urology
Verified
Journal Article
Closed access
TDThomas Karmark Dreyer
Thomas Karmark Dreyer
AEAndreas Ernst
Andreas Ernst
Jørgen Bjerggaard JensenJørgen Bjerggaard Jensen
Jørgen Bjerggaard Jensen
Improving efficiency of follow-up for non-muscle invasive bladder tumours (NMIBC) without risking disease progression through delays of recurrence diagnosis, is a highly relevant field of research....

10 June 2014 in MMW - Fortschritte der Medizin
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Journal Article
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TKTobias Kroll
Tobias Kroll
PSPhilipp Streckbein
Philipp Streckbein
TDThomas Karmark Dreyer
Thomas Karmark Dreyer
BBBirgit Bassaly
Birgit Bassaly
Jens Peter KlussmannJens Peter Klussmann
Jens Peter Klussmann
CWClaus Wittekindt
Claus Wittekindt