Publications by authors named "Per Nyman"

Article Synopsis
  • The ChiCaP study investigates the role of childhood cancer predisposition (ChiCaP) syndromes and how integrating germline whole-genome sequencing (gWGS) with tumor sequencing can improve diagnosis and treatment strategies for children with solid tumors.
  • Out of 309 children tested, 11% were diagnosed with ChiCaP syndromes, often missed before, showing significant diagnostic yield especially in certain cancers like retinoblastomas and high-grade astrocytomas.
  • The findings underscore the importance of combining systematic phenotyping and genomic diagnostics, as it enables personalized care and tailored treatment recommendations for a substantial number of affected patients.
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Article Synopsis
  • A noninferiority trial was conducted to assess if omitting completion axillary-lymph-node dissection is as effective as performing it in patients with clinically node-negative breast cancer and sentinel-lymph-node metastases.
  • A total of 2,766 patients were enrolled, with 1,335 assigned to sentinel-node biopsy only and 1,205 to the dissection group, with a median follow-up of 46.8 months.
  • The results showed a 5-year recurrence-free survival rate of 89.7% for the sentinel-node biopsy-only group, suggesting that this approach may not significantly compromise patient outcomes compared to the traditional method.
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Background: Constitutional mismatch repair deficiency (CMMRD) syndrome is a rare and aggressive cancer predisposition syndrome. Because a scarcity of data on this condition contributes to management challenges and poor outcomes, we aimed to describe the clinical spectrum, cancer biology, and impact of genetics on patient survival in CMMRD.

Methods: In this cohort study, we collected cross-sectional and longitudinal data on all patients with CMMRD, with no age limits, registered with the International Replication Repair Deficiency Consortium (IRRDC) across more than 50 countries.

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Article Synopsis
  • Low-grade gliomas (LGGs) are the most common brain tumors in children, and they require molecular profiling for accurate diagnosis and treatment planning, making liquid biopsy tests crucial for early detection.
  • Researchers analyzed cerebrospinal fluid (CSF) and plasma samples from patients with pilocytic astrocytoma using advanced droplet digital PCR techniques to identify tumor-related genetic changes.
  • The study found circulating tumor DNA (ctDNA) in 5 out of 13 CSF samples, revealing important genetic variations, although most samples had low levels of cell-free DNA, indicating the need for improved analysis methods in understanding LGGs.
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Importance: Medulloblastoma recurrence in patients who have previously received irradiation has a dismal prognosis and lacks a standard salvage regimen.

Objective: To evaluate the response rate of pediatric patients with medulloblastoma recurrence using an antiangiogenic metronomic combinatorial approach (Medulloblastoma European Multitarget Metronomic Anti-Angiogenic Trial [MEMMAT]).

Design, Setting, And Participants: This phase 2, investigator-initiated, multicenter nonrandomized controlled trial assessed 40 patients with relapsed or refractory medulloblastoma without a ventriculoperitoneal shunt who were younger than 20 years at original diagnosis.

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Visual difficulties are common after brain tumors, despite a lack of visual complaints at diagnosis. These include difficulties with eye movements, visual coordination, vergence, accommodation, and photophobia, in addition to more obvious problems such as visual field defects. This case report presents the results of a thorough neuro-visual evaluation in a boy with sequelae after a brain tumor including intermittent double vision that was not explained by routine visual examination.

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Background: Molecular analyses have shown that tumours diagnosed as supratentorial primitive neuro-ectodermal tumours of the central nervous system (CNS-PNETs) in the past represent a heterogenous group of rare childhood tumours including high-grade gliomas (HGG), ependymomas, atypical teratoid/rhabdoid tumours (AT/RT), CNS neuroblastoma with forkhead box R2 (FOXR2) activation and embryonal tumour with multi-layered rosettes (ETMR). All these tumour types are rare and long-term clinical follow-up data are sparse. We retrospectively re-evaluated all children (0-18 years old) diagnosed with a CNS-PNET in Sweden during 1984-2015 and collected clinical data.

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Aims: Paediatric brain tumours are rare, and establishing a precise diagnosis can be challenging. Analysis of DNA methylation profiles has been shown to be a reliable method to classify central nervous system (CNS) tumours with high accuracy. We aimed to prospectively analyse CNS tumours diagnosed in Sweden, to assess the clinical impact of adding DNA methylation-based classification to standard paediatric brain tumour diagnostics in an unselected cohort.

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Background: The elapsed time taken to diagnose tumors of the central nervous system in children and adolescents varies widely. The aim of the present study was to investigate such diagnostic time intervals at a national level in Sweden as they correlate with clinical features.

Methods: Data prospectively accumulated over a 4-year period in the Swedish Childhood Cancer Registry from patients aged 0-18 years were pooled, and diagnostic time intervals were analyzed considering tumor location, tumor type, patient age and sex, initial symptoms, and clinical timelines.

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Purpose: In clinically node-positive breast cancer patients receiving neoadjuvant systemic therapy (NST), nodal metastases can be initially marked and then removed during surgical axillary staging. Marking methods vary significantly in terms of feasibility and cost. The purpose of the extended TATTOO trial was to report on the false-negative rate (FNR) of the low-cost method carbon tattooing.

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Cholesterol-rich clusters of SNARE (soluble NSF attachment protein receptor) proteins have been implicated as being important for exocytosis. Here we demonstrate the significance of cholesterol for normal biphasic insulin secretion in mouse beta cells by removal of cholesterol from the plasma membrane using methyl-beta-cyclodextrin (MBCD). Maximal inhibition of insulin secretion in static incubations was achieved using 0.

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The bifunctional dCTP deaminase-dUTPase (DCD-DUT) from Methanocaldococcus jannaschii catalyzes the deamination of the cytosine moiety in dCTP and the hydrolysis of the triphosphate moiety forming dUMP, thereby preventing uracil from being incorporated into DNA. The crystal structure of DCD-DUT has been determined to 1.88-A resolution and represents the first known structure of an enzyme catalyzing dCTP deamination.

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By the sequential action of dCTP deaminase and dUTPase, dCTP is converted to dUMP, the precursor of thymidine nucleotides. In addition, dUTPase has an essential role as a safeguard against uracil incorporation in DNA. The putative dCTP deaminase (MJ0430) and dUTPase (MJ1102) from the hyperthermophilic archaeon Methanocaldococcus jannaschii were overproduced in Escherichia coli.

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The dut gene, which encodes Escherichia coli deoxyuridine 5'-triphosphate nucleotidohydrolase (dUTPase), has been recloned to increase overexpression of the enzyme and to enable simplification of the purification protocol into a one-step procedure. The gene was cloned into the vector pET-3a and expressed in E. coli BL21(DE3) pLysS under the control of a bacteriophage T7 promotor.

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A peroxidase-encoding gene, mnp2, and its corresponding cDNA were characterized from the white-rot basidiomycete Trametes versicolor PRL 572. We used quantitative reverse transcriptase-mediated PCR to identify mnp2 transcripts in nutrient-limited stationary cultures. Although mnp2 lacks upstream metal response elements (MREs), addition of MnSO(4) to cultures increased mnp2 transcript levels 250-fold.

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