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Dive into the research topics where Krzysztof A. Tomaszewski is active.

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Featured researches published by Krzysztof A. Tomaszewski.


Oxidative Medicine and Cellular Longevity | 2015

The Effect of Age on Osteogenic and Adipogenic Differentiation Potential of Human Adipose Derived Stromal Stem Cells (hASCs) and the Impact of Stress Factors in the Course of the Differentiation Process

Katarzyna Kornicka; Krzysztof Marycz; Krzysztof A. Tomaszewski; Monika Marędziak; Agnieszka Śmieszek

Human adipose tissue is a great source of autologous mesenchymal stem cells (hASCs), which are recognized for their vast therapeutic applications. Their ability to self-renew and differentiate into several lineages makes them a promising tool for cell-based therapies in different types of degenerative diseases. Thus it is crucial to evaluate age-related changes in hASCs, as the elderly are a group that will benefit most from their considerable potential. In this study we investigated the effect of donor age on growth kinetics, cellular senescence marker levels, and osteogenic and adipogenic potential of hASCs. It also has been known that, during life, organisms accumulate oxidative damage that negatively affects cell metabolism. Taking this into consideration, we evaluated the levels of nitric oxide, reactive oxygen species, and superoxide dismutase activity. We observed that ROS and NO increase with aging, while SOD activity is significantly reduced. Moreover cells obtained from older patients displayed senescence associated features, for example, β-galactosidase activity, enlarged morphology, and p53 protein upregulation. All of those characteristics seem to contribute to decreased proliferation potential of those cells. Our results suggest that due to aging some cellular modification may be required before applying aged cells efficiently in therapies such as tissue engineering and regenerative medicine.


Stem Cells International | 2016

The Influence of Aging on the Regenerative Potential of Human Adipose Derived Mesenchymal Stem Cells

Monika Marędziak; Krzysztof Marycz; Krzysztof A. Tomaszewski; Katarzyna Kornicka; Brandon Michael Henry

Tissue regeneration using human adipose derived mesenchymal stem cells (hASCs) has significant potential as a novel treatment for many degenerative bone and joint diseases. Previous studies have established that age negatively affects the proliferation status and the osteogenic and chondrogenic differentiation potential of mesenchymal stem cells. The aim of this study was to assess the age-related maintenance of physiological function and differentiation potential of hASCs in vitro. hASCs were isolated from patients of four different age groups: (1) >20 years (n = 7), (2) >50 years (n = 7), (3) >60 years (n = 7), and (4) >70 years (n = 7). The hASCs were characterized according to the number of fibroblasts colony forming unit (CFU-F), proliferation rate, population doubling time (PDT), and quantified parameters of adipogenic, chondrogenic, and osteogenic differentiation. Compared to younger cells, aged hASCs had decreased proliferation rates, decreased chondrogenic and osteogenic potential, and increased senescent features. A shift in favor of adipogenic differentiation with increased age was also observed. As many bone and joint diseases increase in prevalence with age, it is important to consider the negative influence of age on hASCs viability, proliferation status, and multilineage differentiation potential when considering the potential therapeutic applications of hASCs.


Archives of Gerontology and Geriatrics | 2012

Severe frailty and cognitive impairment are related to higher mortality in 12-month follow-up of nursing home residents.

Paweł Matusik; Krzysztof A. Tomaszewski; Katarzyna Chmielowska; Jan Nowak; Wojciech Nowak; Agnieszka Parnicka; Marzena Dubiel; Jerzy Gąsowski; Tomasz Grodzicki

Frailty syndrome (FS) and cognitive impairment are associated with an increased risk of falls, disability, hospitalization and death. We investigated prognostic meaning of FS and cognitive impairment in persons ≥ 65 years, living in 2 nursing homes. Information about the health status of patients was gathered from history, medical documentation, test assessing FS, according to the Canadian Study of Health and Aging-Clinical Frailty Scale (CSHA-CFS) and the Mini-Mental State Examination (MMSE). The study group included 66 women and 20 men, between 66 and 101 years of age (mean ± S.D.=83.8 ± 8.3 years). The frequency of severe frailty (CSHA-CFS=7) among the elderly living in nursing homes was 34.9%, while severe cognitive impairment (MMSE<18) was present in 55.8%. Residents with severe FS and MMSE<18 consisted 33.7% of examined and 50.0% of those who died during 12-month follow-up, p<0.05. Individuals with severe FS and severe cognitive impairment (n=29) as compared to all other patients, were significantly less probable (59% vs. 79%, p=0.03) to survive one year. Neither frailty, nor dementia, nor severe FS or cognitive impairment when considered separately was associated with higher mortality rate. The risk assessment in severely disabled geriatric patients is best performed with measures of functional and cognitive function considered jointly, but not separately.


Journal of Cellular and Molecular Medicine | 2013

Telocytes: new insight into the pathogenesis of gallstone disease

Andrzej Matyja; Gil K; Artur Pasternak; Krystyna Sztefko; Mariusz Gajda; Krzysztof A. Tomaszewski; Maciej Matyja; Jerzy A. Walocha; Jan Kulig; Thor Pj

The major mechanisms of gallstone formation include biliary cholesterol hypersecretion, supersaturation and crystallization, mucus hypersecretion, gel formation and bile stasis. Gallbladder hypomotility seems to be a key event that triggers the precipitation of cholesterol microcrystals from supersaturated lithogenic bile. Telocytes, a new type of interstitial cells, have been recently identified in many organs, including gallbladder. Considering telocyte functions, it is presumed that these cells might be involved in the signalling processes. The purpose of this study was to correlate the quantity of telocytes in the gallbladder with the lithogenicity of bile. Gallbladder specimens were collected from 24 patients who underwent elective laparoscopic cholecystectomy for symptomatic gallstone disease. The control group consisted of 25 consecutive patients who received elective treatment for pancreatic head tumours. Telocytes were visualized in paraffin sections of gallbladders with double immunofluorescence using primary antibodies against c‐Kit (anti‐CD117) and anti‐mast cell tryptase. Cholesterol, phospholipid and bile acid levels were measured in gallbladder bile. The number of telocytes in the gallbladder wall was significantly lower in the study group than that in the control group (3.03 ± 1.43 versus 6.34 ± 1.66 cell/field of view in the muscularis propria, P < 0.001) and correlated with a significant increase in the cholesterol saturation index. The glycocholic and taurocholic acid levels were significantly elevated in the control subjects compared with the study group. The results suggest that bile composition may play an important role in the reduction in telocytes density in the gallbladder.


Annals of Anatomy-anatomischer Anzeiger | 2016

Methods of Evidence-Based Anatomy: a guide to conducting systematic reviews and meta-analysis of anatomical studies.

Brandon Michael Henry; Krzysztof A. Tomaszewski; Jerzy A. Walocha

Evidence-Based Anatomy (EBA) is the concept of applying evidence-based principles and research methods to the anatomical sciences. While narrative reviews are common in the anatomical sciences, true systematic reviews (SR) and meta-analysis (MA) are only beginning to grow in popularity. In order to enhance the quality of future EBA studies, and ensure the clinical reliability of their results, a uniform methodology is needed. In this paper, we present a step-by-step methodological guide for performing SRs and MAs of anatomical studies. We address the EBA-specific challenges in each step of the SR and MA process, and discuss methods and strategies to overcome these difficulties. Furthermore, we discuss in detail the statistical methods used in MA of anatomical data, including multi-categorical and single-categorical pooled prevalence estimates, as well as pooled means of one group. Lastly, we discuss the major limitations of EBA, including the lack of a proper quality assessment tool for anatomical studies. The methods described in this paper present a uniform road map for future EBA studies.


Clinical Anatomy | 2017

Development of the Anatomical Quality Assurance (AQUA) checklist: Guidelines for reporting original anatomical studies

Krzysztof A. Tomaszewski; Brandon Michael Henry; Piravin Kumar Ramakrishnan; Joyeeta Roy; Jens Vikse; Marios Loukas; R. Shane Tubbs; Jerzy A. Walocha

The rise of evidence‐based anatomy has emphasized the need for original anatomical studies with high clarity, transparency, and comprehensiveness in reporting. Currently, inconsistencies in the quality and reporting of such studies have placed limits on accurate reliability and impact assessment. Our aim was to develop a checklist of reporting items that should be addressed by authors of original anatomical studies. The study steering committee formulated a preliminary conceptual design and began to generate items on the basis of a literature review and expert opinion. This led to the development of a preliminary checklist. The validity of this checklist was assessed by a Delphi procedure, and feedback from the Delphi panelists, who were experts in the area of anatomical research, was used to improve it. The Delphi procedure involved 12 experts in anatomical research. It comprised two rounds, after which unanimous consensus was reached regarding the items to be included in the checklist. The steering committee agreed to name the checklist AQUA. The preliminary AQUA Checklist consisted of 26 items divided into eight sections. Following round 1, some of the items underwent major revision and three new ones were introduced. The checklist was revised only for minor language inaccuracies after round 2. The final version of the AQUA Checklist consisted of the initial eight sections with a total of 29 items. The steering committee hopes the AQUA Checklist will improve the quality and reporting of anatomical studies. Clin. Anat. 30:14–20, 2017.


Clinical Anatomy | 2017

Development of the anatomical quality assessment (AQUA) tool for the quality assessment of anatomical studies included in meta‐analyses and systematic reviews

Brandon Michael Henry; Krzysztof A. Tomaszewski; Piravin Kumar Ramakrishnan; Joyeeta Roy; Jens Vikse; Marios Loukas; R. Shane Tubbs; Jerzy A. Walocha

Critical appraisal of anatomical studies is essential before the evidence from them undergoes meta‐epidemiological synthesis. However, no instrument for appraising anatomical studies with inherent applicability to different study designs is available. We aim to develop a generic yet comprehensive tool for assessing the quality of anatomical studies using a formal consensus method. The study steering committee formulated an initial conceptual design and generated items for a preliminary tool on the basis of a literature review and expert opinion. A Delphi procedure was then adopted to assess the validity of the preliminary tool. Feedback from the Delphi panelists was used to improve it. The Delphi procedure involved 12 experts in anatomical research. It comprised two rounds, after which unanimous consensus was reached about the items to be included. The preliminary tool consisted of 20 items, which were phrased as signaling questions and organized into five domains: 1. Aim and subject characteristics, 2. Study design, 3. Characterization of methods, 4. Descriptive anatomy, and 5. Results reporting. Each domain was set to end with a risk of bias question. Following round 1, some of the items underwent major revision, although agreement was reached regarding inclusion of all the domains and signaling questions in the preliminary tool. The tool was revised only for minor language inaccuracies after round 2. The AQUA Tool was designed to assess the quality and reliability of anatomical studies. It is currently undergoing a validation process. Clin. Anat. 30:6–13, 2017.


PLOS ONE | 2015

The Prevalence of Anatomical Variations of the Median Nerve in the Carpal Tunnel: A Systematic Review and Meta-Analysis

Brandon Michael Henry; Helena Zwinczewska; Joyeeta Roy; Jens Vikse; Piravin Kumar Ramakrishnan; Jerzy A. Walocha; Krzysztof A. Tomaszewski

Background and Objective The course and branches of the median nerve (MN) in the wrist vary widely among the population. Due to significant differences in the reported prevalence of such variations, extensive knowledge on the anatomy of the MN is essential to avoid iatrogenic nerve injury. Our aim was to determine the prevalence rates of anatomical variations of the MN in the carpal tunnel and the most common course patterns and variations in its thenar motor branch (TMB). Study Design A systematic search of all major databases was performed to identify articles that studied the prevalence of MN variations in the carpal tunnel and the TMB. No date or language restrictions were set. Extracted data was classified according to Lanzs classification system: variations in the course of the single TMB—extraligamentous, subligamentous, and transligamentous (type 1); accessory branches of the MN at the distal carpal tunnel (type 2); high division of the MN (type 3); and the MN and its accessory branches proximal to the carpal tunnel (type 4). Pooled prevalence rates were calculated using MetaXL 2.0. Results Thirty-one studies (n = 3918 hands) were included in the meta-analysis. The pooled prevalence rates of the extraligamentous, subligamentous, and transligamentous courses were 75.2% (95%CI:55.4%-84.7%), 13.5% (95%CI:3.6%-25.7%), and 11.3% (95%CI:2.4%-23.0%), respectively. The prevalence of Lanz group 2, 3, and 4 were 4.6% (95%CI:1.6%-9.1%), 2.6% (95%CI:0.1%-2.8%), and 2.3% (95%CI:0.3%-5.6%), respectively. Ulnar side of branching of the TMB was found in 2.1% (95%CI:0.9%-3.6%) of hands. The prevalence of hypertrophic thenar muscles over the transverse carpal ligament was 18.2% (95%CI:6.8%-33.0%). A transligamentous course of the TMB was more commonly found in hands with hypertrophic thenar muscles (23.4%, 95%CI:5.0%-43.4%) compared to those without hypertrophic musculature (1.7%, 95%CI:0%-100%). In four studies (n = 423 hands), identical bilateral course of the TMB was found in 72.3% (95%CI:58.4%-84.4%) of patients. Conclusions Anatomical variations in the course of the TMB and the MN in the carpal tunnel are common in the population. Thus, we recommend an ulnar side approach to carpal tunnel release, with a careful layer by layer dissection, to avoid iatrogenic damage to the TMB.


International Journal of Infectious Diseases | 2015

The role of serum procalcitonin in the diagnosis of bacterial meningitis in adults: a systematic review and meta-analysis

Jens Vikse; Brandon Michael Henry; Joyeeta Roy; Piravin Kumar Ramakrishnan; Krzysztof A. Tomaszewski; Jerzy A. Walocha

OBJECTIVE Clinically, it is often difficult to differentiate between bacterial and viral aetiologies in adults with suspected meningitis. Several studies have demonstrated the potential use of serum procalcitonin (PCT) in making this differentiation. The aim was to pool these studies into a meta-analysis to determine the diagnostic accuracy of PCT. METHODS Major electronic databases were searched for articles studying the use of serum PCT in the differentiation of bacterial and viral meningitis in adult patients. No date or language restrictions were applied. Data analysis was performed using Meta-DiSc 1.4 and MIX 2.0. RESULTS Nine studies (n=725 patients) were included in the meta-analysis. Serum PCT was found to be a highly accurate test for diagnosing meningitis. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio (DOR) for PCT were 0.90 (95% confidence interval (CI) 0.84-0.94), 0.98 (95% CI 0.97-0.99), 27.3 (95% CI 8.2-91.1), 0.13 (95% CI 0.07-0.26), and 287.0 (95% CI 58.5-1409.0), respectively. PCT was found to be far superior to C-reactive protein, which had a pooled DOR of only 22.1 (95% CI 12.7-38.3). CONCLUSIONS Serum PCT is a highly accurate diagnostic test that can be used by physicians for rapid differentiation between bacterial and viral causes of meningitis in adults.


European Journal of Obstetrics & Gynecology and Reproductive Biology | 2013

Assessment of knowledge about cervical cancer and its prevention among female students aged 17-26 years

Wojciech Kamzol; Katarzyna Jaglarz; Krzysztof A. Tomaszewski; Mirosława Püsküllüoğlu; Krzysztof Krzemieniecki

OBJECTIVE To assess knowledge about cervical cancer and its primary and secondary prevention, and identify the sources of information about the disease among female high school and university students in Krakow, Poland. STUDY DESIGN This study was based on a questionnaire consisting of 64 questions, divided into six parts: personal data, general knowledge about cervical cancer, estimation of risk factors, knowledge about primary prevention, knowledge about secondary prevention, and information sources. Data were collected from students aged 17-26 years over a 3-month period in 2011 and 2012. RESULTS Four hundred women living in Krakow or its vicinity were included in the study. Nearly all respondents (98.5%) had heard of cervical cancer, 89.4% were aware of the risk of death associated with cervical cancer, and 44.8% believed that the disease could affect them in the future. The interviewees considered genetics and family history to be the most important risk factors, followed by infection with human papillomavirus (HPV) and having multiple sex partners. Most (91.5%) respondents had not been vaccinated against HPV, 47.9% did not know where to go to get vaccinated, and 30.1% were unaware of vaccination as a prevention method. Most (91.5%) respondents were aware of cytological screening, and 86.5% thought that they should have it done in the future. Women who had not heard of cytological screening were more likely to be unaware of cervical cancer than women who had heard about cytological screening (odds ratio 0.24, 95% confidence interval 0.11-0.49, p=0.0001). The Internet, television and newspapers were reported to be the main sources of information about the disease. CONCLUSIONS General awareness of cervical cancer among young women in Poland is insufficient. HPV infection is not considered to be the major aetiological factor. A relatively high percentage of women in this study had never heard of the HPV vaccine as a way of preventing cervical cancer. Knowledge about cytological screening, however, appears to be much better.

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Brandon Michael Henry

Jagiellonian University Medical College

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Jerzy A. Walocha

Jagiellonian University Medical College

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Przemysław A. Pękala

Jagiellonian University Medical College

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Jens Vikse

Jagiellonian University Medical College

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Iwona M. Tomaszewska

Jagiellonian University Medical College

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Ewa Mizia

Jagiellonian University Medical College

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Joyeeta Roy

Jagiellonian University Medical College

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R. Shane Tubbs

University of Alabama at Birmingham

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Artur Pasternak

Jagiellonian University Medical College

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