Marcin Rojek

Mr. Marcin Rojek

orcid

Research Focus & Metrics

Academic Career Length

10Years (2017-Present)

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

Representative Publications

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1 December 2017 in Medicine
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MRMarcin Rojek
Marcin Rojek
MRMarek W Rajzer
Marek W Rajzer
WWWiktoria Wojciechowska
Wiktoria Wojciechowska
Jerzy GąsowskiJerzy Gąsowski
Jerzy Gąsowski
TPTomasz Pizoń
Tomasz Pizoń
DCDanuta Czarnecka
Danuta Czarnecka
Left atrial enlargement (LAE) is a risk factor for cardiovascular complications and death. In hypertensive patients, LAE is usually due to left ventricular (LV) hypertrophy and diastolic dysfunction. We aimed to identify factors associated with LAE in patients with increased and normal left ventricular mass index (LVMI) with reference to pulsatile and steady components of blood pressure (BP). The study was carried out as a cross-sectional observation. In a group of inhabitants of suburban area of Cracow, Poland, we measured office, ambulatory and central BP, carotid-femoral pulse wave velocity (PWV), as well as echocardiographic indices and gathered anthropometric data, information on habits and relevant medical history. Further, with division according to sex-stratified dichotomised LVMI, we performed correlation analysis to identify possibly significant relations between measures of left atrial volume and other studied parameters. We also fitted regression models in order to assess the respective value of steady and pulsatile BP components as factors related to measures of left atrial volume. The mean age of 205 patients (136 females—66%) was 53.6 ± 8.3 years. We found higher values of PWV, office, ambulatory and central BPs in the group of LVMI above median value. This group had also greater left atrial volume index (LAVI), which correlated with LVMI (r = 0.36, P < .001) and ratio of early diastolic mitral peak flow velocity to early diastolic mitral annulus mean velocity in tissue Doppler imaging (E/e′) (r = 0.24, P = .04). In the group of LVMI below the median, LAVI correlated with pulsatile and steady BP components. LAVI was independently predicted by mean arterial pressure (MAP) obtained from both ambulatory (MAP24h, β= 0.15; P = .045) and office measurements (MAPoffice, β = 0.35; P = .004), but not by pulse pressure. LV mass and function are the main determinants of LAVI. However, in persons with lower LV mass, LAVI depends on the steady component of blood pressure, but not pulsatile one. Increased LAVI reflects early changes in response to systemic blood pressure elevation.

1 October 2018 in Journal of the Renin-Angiotensin-Aldosterone System
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TPTomasz Pizoń
Tomasz Pizoń
MRMarek W Rajzer
Marek W Rajzer
WWWiktoria Wojciechowska
Wiktoria Wojciechowska
MWMałgorzata Wach-Pizoń
Małgorzata Wach-Pizoń
TDTomasz Drożdż
Tomasz Drożdż
DCDanuta Czarnecka
Danuta Czarnecka
Introduction: The aim of the study was to evaluate clinical and biochemical differences between patients with low-renin and high-renin primary arterial hypertension (AH), mainly in reference to serum lipids, and to identify factors determining lipid concentrations. Materials and methods: In untreated patients with AH stage 1 we measured plasma renin activity (PRA) and subdivided the group into low-renin (PRA < 0.65 ng/mL/h) and high-renin (PRA ⩾ 0.65 ng/mL/h) AH. We compared office and 24-h ambulatory blood pressure, serum aldosterone, lipids and selected biochemical parameters between subgroups. Factors determining lipid concentration in both subgroups were assessed in regression analysis. Results: Patients with high-renin hypertension ( N = 58) were characterized by higher heart rate ( p = 0.04), lower serum sodium ( p < 0.01) and aldosterone-to-renin ratio ( p < 0.01), and significantly higher serum aldosterone ( p = 0.03), albumin ( p < 0.01), total protein ( p < 0.01), total cholesterol ( p = 0.01) and low-density lipoprotein cholesterol (LDL-C) ( p = 0.04) than low-renin subjects ( N = 39). In univariate linear regression, only PRA in the low-renin group was in a positive relationship with LDL-C ( R2 = 0.15, β = 1.53 and p = 0.013); this association remained significant after adjustment for age, sex, and serum albumin and aldosterone concentrations. Conclusions: Higher serum levels of total and LDL-C characterized high-renin subjects, but the association between LDL-C level and PRA existed only in low-renin primary AH.

25 October 2024 in Biomedicines
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SMSandra Modlińska
Sandra Modlińska
MRMarcin Rojek
Marcin Rojek
MBMichał Bielówka
Michał Bielówka
Jakub KufelJakub Kufel
Jakub Kufel
Background/Objectives: Head Computed Tomography (CT) is an essential diagnostic tool for identifying brain pathologies and visualizing blood vessels. However, CT exposes patients to ionizing radiation, making it necessary to establish local diagnostic reference levels (DRLs) to ensure patient safety. This study aimed to establish DRLs for head CT scans and assess the influence of patient characteristics on radiation dose. Methods: A retrospective analysis was conducted on 2043 non-contrast and 488 contrast-enhanced head CT scans performed between 1 July 2023 and 31 March 2024 using a SIEMENS SOMATOM Definition Edge machine. Computed Tomography Dose Index (CTDIvol) and Dose-Length Product (DLP) values were analyzed, with DRLs set at the 75th percentile. The influence of gender, height, and weight on radiation dose was also evaluated. Results: The DRL for both non-contrast and contrast-enhanced scans was 58.18 mGy for CTDIvol and 1018.11 mGy·cm for DLP per acquisition. Total DLP was 2046.09 mGy·cm for contrast-enhanced and 1027.99 mGy·cm for non-contrast scans. No significant correlation was found between patient characteristics and radiation dose, allowing for a uniform DRL to be established. Conclusions: Uniform DRLs were successfully established for head CT scans, ensuring safe radiation doses for both non-contrast and contrast-enhanced studies. The lack of correlation between patient-specific factors and dose supports the use of standardized DRLs, contributing to optimized radiation safety in head CT diagnostics.

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MDMagdalena Dębiec
Magdalena Dębiec
MRMarcin Rojek
Marcin Rojek
Adult neurogenesis, the process of generating new, functional neurons in the mature central nervous system, represents a key mechanism of brain plasticity and a potential source of regeneration. This process occurs primarily within specialised neurogenic niches: the subgranular zone of the hippocampal dentate gyrus (SGZ) and the subependymal zone (SEZ). It is regulated by a complex network of endogenous factors (e.g., hormones, neurotrophins, growth factors) and exogenous factors (environment, stress, diet, physical activity). Impairments in neurogenesis are linked to the pathogenesis of neurodegenerative diseases, such as Alzheimer’s disease (AD) and Parkinson’s disease (PD). In their course, chronic inflammation, mitochondrial dysfunction, oxidative stress, and the accumulation of pathological proteins (β-amyloid, Tau protein, α-synuclein) create a microenvironment that inhibits the proliferation, differentiation, and survival of new neurons. This results in the exacerbation of cognitive and memory deficits. A review of the literature indicates that modulating neurogenesis through non-pharmacological interventions (e.g., a diet rich in anti-inflammatory compounds, physical exercise) and targeted therapeutic strategies represents a promising, albeit complex, research avenue. The primary challenge remains not only stimulating neuron generation but also ensuring their proper maturation, survival, and functional integration into existing neuronal circuits. A deeper understanding of the molecular and environmental mechanisms regulating adult neurogenesis may open new therapeutic possibilities for slowing the progression of neurodegenerative diseases.

9 August 2024 in Brain Sciences
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SMSandra Modlińska
Sandra Modlińska
Jakub KufelJakub Kufel
Jakub Kufel
Michał JanikMichał Janik
Michał Janik
Łukasz CzogalikŁukasz Czogalik
Łukasz Czogalik
PDPiotr Dudek
Piotr Dudek
MZMiłosz Zbroszczyk
Miłosz Zbroszczyk
Cerebral vascular angiography, or digital subtraction angiography (DSA), is essential for diagnosing neurological conditions but poses radiation risks. This study aims to analyze the impact of examination parameters and patient characteristics on the radiation dose received during DSA to optimize safety and minimize exposure. A retrospective analysis of 251 DSA procedures using the GE Innova IGS 630 dual-plane instrument was conducted. Data on dose area product (DAP) and air kerma (KERMA), along with patient and examination details, were collected. Statistical analyses, including Mann–Whitney, Kruskal–Wallis, and Spearman rank correlation tests, assessed the relationships between variables and radiation dose outcomes. Significant correlations were found between the sides examined (left, right, or both) and DAP (p < 0.0001) and KERMA (p < 0.0001) values, with bilateral studies showing the highest values. The post hoc Dunn tests showed that the ‘L + P’ group significantly differs from both the right group (p < 0.0001 and the left group (p < 0.0001). There is no significant difference between the ‘P’ group and the ‘L’ group (p-value = 0.53). These results suggest that the right and left (both) group have unique KERMA mGy values compared to the other two groups. A strong correlation (rS = 0.87) existed between DAP and KERMA. The number of projections significantly impacted radiation dose (rS = 0.61). Tube parameters (kV and mA) and skull size had low correlations with DAP and KERMA. Optimizing imaging protocols and individualizing parameters can significantly enhance patient safety and diagnostic efficacy while also reducing occupational exposure for medical staff.

7 February 2025 in BMJ Open
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PLPiotr Lewandowski
Piotr Lewandowski
MBMaciej Baron
Maciej Baron
MRMarcin Rojek
Marcin Rojek
MGMarcin Goławski
Marcin Goławski
KKKarol Krystek
Karol Krystek
RWRomuald Wojnicz
Romuald Wojnicz
Introduction: Myocarditis is an inflammatory heart disease resulting from infections, toxic exposures or autoimmune reactions. Irrespective of the factors responsible for this disease, cytokines play an important role in regulating the immunological response involved in its development and progression. Accordingly, this protocol aims to conduct a systematic review and meta-analysis summarising previous research on serum and plasma levels of cytokines in patients with myocarditis and inflammatory dilated cardiomyopathy. Methods and analysis: Four scientific databases: PubMed, Embase, Scopus and Web of Science, will be searched. The estimated date of the search will be 30 March 2024. Each stage of the review, including the study selection, data extraction, risk of bias and quality of evidence assessments, will be performed in duplicate. Studies meeting the following criteria will be eligible for inclusion: (1) studies involving ‘myocarditis’ or ‘inflammatory dilated cardiomyopathy’ and (2) studies are required to report serum levels of any cytokine. Meta-analyses will be used to summarise serum levels of each cytokine if possible. Subgroup analysis will be stratified by age, sex, sample size, New York Heart Association scale, cardiac Troponin T, N-terminal prohormone of brain natriuretic peptide, C reactive protein, number of lymphocytes per mm 2 in the endomyocardial biopsy. Ethics approval and dissemination: This study does not require ethics approval. After completion, the results will be published in a peer-reviewed paper. Data generated during the study will be published in an open access repository. PROSPERO registration number: CRD42024519625