Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Leszek Pawelczyk is active.

Publication


Featured researches published by Leszek Pawelczyk.


Histochemistry and Cell Biology | 2007

Immunohistochemical localization of advanced glycation end-products (AGEs) and their receptor (RAGE) in polycystic and normal ovaries

Evanthia Diamanti-Kandarakis; Christina Piperi; Efstratios Patsouris; Penelope Korkolopoulou; Dimitrios Panidis; Leszek Pawelczyk; Athanasios G. Papavassiliou; Antoni J. Duleba

The aim of the present study was to investigate the localization/immunohistochemical distribution of AGEs and RAGE, as well as their putative signalling mediator NF-κB in ovaries of women with polycystic ovary syndrome (PCOS) compared to normal. Archival ovarian-tissue samples from biopsies of six women with PCOS and from six healthy of similar age women, were examined immunohistochemically with monoclonal anti-AGEs, anti-RAGE and anti-NF-κB(p50/p65) specific antibodies. In healthy women, AGE immunoreactivity was observed in follicular cell layers (granulosa and theca) and luteinized cells, but not in endothelial cells. PCOS specimens displayed AGE immunoexpression in theca interna and granulosa cells as well as in endothelial cells, but staining of granulosa cells was stronger than in that of normal ovaries. RAGE was highly expressed in normal and PCOS tissues. Normal tissue exhibited no staining differences between granulosa cell layer and theca interna. However, in PCOS ovaries, granulosa cells displayed stronger RAGE expression compared to theca interna cells in comparison to controls. NF-κB(p50/p65) was expressed in the cytoplasm of theca interna and granulosa cells of both normal and PCOS ovaries; whereas the NF-κB p65 subunit was only observed in granulosa cells nuclei in PCOS tissue. In conclusion, these findings demonstrate for the first time that RAGE and AGE-modified proteins with activated NF-κB are expressed in human ovarian tissue. Furthermore, a differential qualitative distribution of AGE, RAGE and NF-κB p65 subunit was observed in women with PCOS compared to healthy controls, where a stronger localization of both AGE and RAGE was observed in the granulosa cell layer of PCOS ovaries.


The Journal of Clinical Endocrinology and Metabolism | 2009

Comparison of Simvastatin and Metformin in Treatment of Polycystic Ovary Syndrome: Prospective Randomized Trial

Beata Banaszewska; Leszek Pawelczyk; Robert Z. Spaczynski; Antoni J. Duleba

CONTEXT Polycystic ovary syndrome (PCOS) is characterized by ovarian dysfunction and hyperandrogenism; it is also associated with increased cardiovascular risks such as adverse lipid profile and endothelial dysfunction. Metformin and, more recently, statins have been shown to improve endocrine and metabolic aspects of PCOS. OBJECTIVE The aim of the study was to compare effects of simvastatin and metformin on PCOS. DESIGN In a prospective trial, women with PCOS (n = 136) were randomized to simvastatin (S), metformin (M), or simvastatin plus metformin (SM) groups. Evaluations were performed at baseline and after 3 months. SETTING The study was conducted at an academic medical center. PRIMARY OUTCOME The change of serum total testosterone was measured. RESULTS The study was completed by 113 subjects. Total testosterone decreased significantly and comparably in all groups: by 17.1, 13.6, and 15.1%, respectively, in the S, M, and SM groups. Significant decreases were also observed in all groups with respect to body mass index, C-reactive protein, and soluble vascular cell adhesion molecule-1. DHEAS declined significantly only in the S group. None of the treatments were associated with significant changes in LH or FSH. Total cholesterol and low-density lipoprotein cholesterol significantly declined only in S and SM groups. CONCLUSIONS Simvastatin treatment was superior to metformin alone, whereas a combination of simvastatin and metformin was not significantly superior to simvastatin alone.


The Journal of Clinical Endocrinology and Metabolism | 2011

Effects of simvastatin and metformin on polycystic ovary syndrome after six months of treatment.

Beata Banaszewska; Leszek Pawelczyk; Robert Z. Spaczynski; Antoni J. Duleba

CONTEXT A randomized trial on women with polycystic ovary syndrome (PCOS) compared simvastatin, metformin, and a combination of these drugs. OBJECTIVE The aim of the study was to evaluate long-term effects of simvastatin and metformin on PCOS. DESIGN Women with PCOS (n = 139) were randomized to simvastatin (S), metformin (M), or simvastatin plus metformin (SM) groups. Evaluations were performed at baseline and at 3 and 6 months. SETTING The study was conducted at a university medical center. PRIMARY OUTCOME We measured the change of serum total testosterone. RESULTS Ninety-seven subjects completed the study. Total testosterone decreased significantly and comparably in all groups: by 25.6, 25.6, and 20.1% in the S, M, and SM groups, respectively. Both simvastatin and metformin improved menstrual cyclicity and decreased hirsutism, acne, ovarian volume, body mass index, C-reactive protein, and soluble vascular cell adhesion molecule-1. Dehydroepiandrosterone sulfate declined significantly only in the S group. Total cholesterol and low-density lipoprotein cholesterol significantly declined only in the S and SM groups. Ongoing reduction of ovarian volume, decreased hirsutism, acne and testosterone were observed between 0 and 3 months as well as between 3 and 6 months. Improvement of lipid profile, C-reactive protein, and soluble vascular cell adhesion molecule-1 occurred only during the first 3 months of treatment, with little change thereafter. Treatments were well tolerated, and no significant adverse effects were encountered. CONCLUSIONS Long-term treatment with simvastatin was superior to metformin. Improvement of ovarian hyperandrogenism continued throughout the duration of the study.


Fertility and Sterility | 2003

Success of laparoscopic ovarian wedge resection is related to obesity, lipid profile, and insulin levels

Antoni J. Duleba; Beata Banaszewska; Robert Z. Spaczynski; Leszek Pawelczyk

OBJECTIVE To evaluate the effects of laparoscopic ovarian wedge resection on hormonal and metabolic parameters of polycystic ovary syndrome (PCOS) and to compare profiles of women who achieved pregnancy with those who did not. DESIGN Prospective study. SETTING University hospital. PATIENT(S) Thirty-three women with PCOS. INTERVENTION(S) Laparoscopic ovarian wedge resection using harmonic scalpel. MAIN OUTCOME MEASURE(S) Pregnancy; levels of testosterone, DHEAS, gonadotropins, sex hormone-binding globulin (SHBG), and glucose and insulin during 2-hour glucose tolerance test; lipid profile; body mass index; and waist-to-hip ratio. RESULT(S) Twenty-two women (67%) achieved clinical pregnancy within the mean of 4.9 months after surgery. Baseline parameters of women who became pregnant differed from those who did not: those who became pregnant were less obese, had lower levels of total cholesterol, low-density lipoprotein, and triglycerides; higher levels of SHBG; lower levels of fasting insulin; lower insulin area under the curve; and higher insulin sensitivity index. Subjects not pregnant by 12 weeks after surgery underwent repeat endocrine and metabolic evaluations. In these women, wedge resection was followed by declines in testosterone, LH, and insulin sensitivity index. Wedge resection had no significant effect on SHBG, DHEAS, or lipid profile. CONCLUSION(S) Laparoscopic wedge resections are associated with the highest pregnancy rates among less obese subjects with favorable lipid profiles and lower insulin. In this study, the postoperative decline of serum testosterone and LH is not attributable to improvement of insulin sensitivity.


Journal of Cellular and Molecular Medicine | 2010

Lysyl oxidase interacts with AGE signalling to modulate collagen synthesis in polycystic ovarian tissue

Katerina K. Papachroni; Christina Piperi; Georgia Levidou; Penelope Korkolopoulou; Leszek Pawelczyk; Evanthia Diamanti-Kandarakis; Athanasios G. Papavassiliou

Connective tissue components – collagen types I, III and IV – surrounding the ovarian follicles undergo drastic changes during ovulation. Abnormal collagen synthesis and increased volume and density of ovarian stroma characterize the polycystic ovary syndrome (PCOS). During the ovulatory process, collagen synthesis is regulated by prolyl hydroxylase and lysyl oxidase (LOX) activity in ovarian follicles. LOX catalyzes collagen and elastin cross‐linking and plays essential role in coordinating the control of ovarian extracellular matrix (ECM) during follicular development. We have recently shown accumulation of advanced glycation end products (AGEs), molecules that stimulate ECM production and abnormal collagen cross‐linking, in ovarian tissue. However, the possible link between LOX and AGEs‐induced signalling in collagen production and stroma formation in ovarian tissue from PCOS remains elusive. The present study investigates the hypothesis of AGE signalling pathway interaction with LOX gene activity in polycystic ovarian (PCO) tissue. We show an increased distribution and co‐localization of LOX, collagen type IV and AGE molecules in the PCO tissue compared to control, as well as augmented expression of AGE signalling mediators/effectors, phospho(p)‐ERK, phospho(p)‐c‐Jun and nuclear factor κB (NF‐κB) in pathological tissue. Moreover, we demonstrate binding of AGE‐induced transcription factors, NF‐κB and activator protein‐1 (AP‐1) on LOX promoter, indicating a possible involvement of AGEs in LOX gene regulation, which may account for the documented increase in LOX mRNA and protein levels compared to control. These findings suggest that deposition of excess collagen in PCO tissue that induces cystogenesis may, in part, be due to AGE‐mediated stimulation of LOX activity.


Journal of Medical Genetics | 2001

Mosaicism for 45,X cell line may accentuate the severity of spermatogenic defects in men with AZFc deletion

Jadwiga Jaruzelska; Aleksandra Korcz; Alina Wojda; Piotr Jedrzejczak; Joanna Bierla; Tatiana Surmacz; Leszek Pawelczyk; David C. Page; Maciej Kotecki

Editor—Over the past 10 years, several authors have reported microdeletions in the long arm of the Y chromosome (Yq) in men with idiopathic, non-obstructive azoospermia or severe oligospermia. These microdeletions were clustered on the Yq fragment previously described as the azoospermia factor region (AZF).1 More recently, a number of genes expressed specifically in the testes and mapping to AZFa, AZFb, or AZFc subregions have been cloned.2-4 One of the approaches to understanding the role of these genes in human spermatogenesis is to look for a correlation between the lack of given AZF genes and the particular spermatogenic defect in the phenotypes of the patients. However, attempts to find such a correlation have failed so far. Instead, a broad spectrum of phenotypes ranging clinically from azoospermia to severe oligospermia and histologically from Sertoli cell only syndrome (SCOS) to hypospermatogenesis has been described in association with AZFc deletions.5 6 A recent study found chromosomal aberrations in 15% of azoospermic patients.7 However, in papers focusing on the analysis of AZF microdeletions in patients with idiopathic infertility,2 3 5 8-30 systematic, bilateral, histological, molecular, and cytogenetic analyses in the same large group of patients was rarely carried out, thus limiting information on the coexistence of AZF deletions and chromosomal aberrations. In this study, we propose and test the hypothesis that chromosomal defects may often accompany AZF deletions and cause the lack of a genotype-phenotype correlation in human male idiopathic infertility. We also attempt to evaluate the nature of the spermatogenetic failure associated with isolated AZFc deletions. For this purpose, we performed a dual genetic analysis of karyotypes and molecular status of the AZF region along with bilateral testicular histological evaluation in 94 patients with non-obstructive, idiopathic infertility and azoospermia, severe oligospermia, or oligospermia. Sixty five men with …


Archives of Andrology | 2007

Quantitative assessment of transition proteins 1, 2 spermatid-specific linker histone H1-like protein transcripts in spermatozoa from normozoospermic and asthenozoospermic men.

Piotr Jedrzejczak; Bartosz Kempisty; Artur Bryja; Magdalena Mostowska; Magdalena Depa-Martynow; Leszek Pawelczyk; Paweł P. Jagodziński

Spermatid-specific linker histone H1-like protein (HILS1), transition proteins 1 and 2 (TNP1 and TNP2), and protamines 1 and 2 (PRM1 and PRM2) contribute to considerable dense packing of spermatid chromatin during spermiogenesis. We evaluated the HILS1, TNP1, and TNP2 transcript levels in spermatozoa isolated from normozoospermic and asthenozoospermic men. Human ejaculates from normozoospermic (n = 70) and asthenozoospermic (n = 100) donors were purified by centrifugation through a discontinuous Percoll density gradient. RNA was isolated from spermatozoa according to the Chomczyński and Sacchi method, treated with DNase I and reverse-transcribed into cDNA. Quantitative analysis of HILS1, TNP1, and TNP2 transcripts was performed by real-time quantitative (RQ-PCR) SYBR green I analysis. We found significantly lower levels of HILS1, TNP1, and TNP2 transcripts in spermatozoa from asthenozoospermic men compared to normozoospermic men. Our observations suggest that a reduction in HILS1, TNP1, and TNP2 transcripts may be associated with asthenozoospermia.


Archives of Andrology | 2006

QUANTITATIVE ANALYSIS OF CCR5 CHEMOKINE RECEPTOR AND CYTOCHROME P450 AROMATASE TRANSCRIPTS IN SWIM-UP SPERMATOZOA ISOLATED FROM FERTILE AND INFERTILE MEN

Piotr Jedrzejczak; R. Januchowski; G. Taszarek-Hauke; R. Laddach; Leszek Pawelczyk; Paweł P. Jagodziński

We determined the CCR5 chemokine receptor and cytochrome P450 aromatase (P450arom) transcript copies number in swim-up sperm isolated from fertile and infertile men. The ejaculates were purified by centrifugation through discontinuous Percoll density gradient and swim-up techniques. RNA was isolated from sperm, treated with DNase I and reverse-transcribed into cDNA. Quantitative analysis of CCR5 and P450arom cDNA were performed by real-time quantitative (RQ-PCR) SYBR Green I analysis. There was a higher content of CCR5 and P450arom transcripts copy number in swim-up sperm of fertile than from infertile donors. The decrease in CCR5 and P450arom transcripts in swim-up sperm may be associated with male infertility.


Journal of Medical Genetics | 2013

Mutations of NANOS1, a human homologue of the Drosophila morphogen, are associated with a lack of germ cells in testes or severe oligo-astheno-teratozoospermia

Kamila Kusz-Zamelczyk; Marcin Sajek; Anna Spik; Renata Glazar; Piotr Jedrzejczak; Anna Latos-Bielenska; Maciej Kotecki; Leszek Pawelczyk; Jadwiga Jaruzelska

Background The Nanos gene is a key translational regulator of specific mRNAs involved in Drosophila germ cell development. Disruption of mammalian homologues, Nanos2 or Nanos3, causes male infertility in mice. In humans, however, no evidence of NANOS2 or NANOS3 mutations causing male infertility has been reported. Although Nanos1 seems dispensable for mouse reproduction, we sought to analyse for the first time its homologue in infertile men. Methods A group of 195 patients manifesting non-obstructive azoospermia or oligozoospermia were tested for mutations of the NANOS1 gene, using single-strand conformation polymorphism and DNA sequencing. Results Three types of NANOS1 gene mutations were identified in five patients and were absent in 800 chromosomes of fertile men. Pedigree analysis indicated a dominant inheritance pattern with penetration limited to males. Two mutations caused deletions of single amino acids, p.Pro77_Ser78delinsPro and p.Ala173del, each of them identified in two unrelated patients. Both types of deletions were located in the NANOS1 N-terminus (responsible for protein interactions) and were associated with a lack of germ cells in testes. Interestingly, the Pro77_Ser78delinsPro mutation altered interaction of NANOS1 with a microRNA biogenesis factor, GEMIN3. The third identified mutation, p.[(Arg246His; Arg276Tyr)], found in the C-terminal RNA-binding domain, was present in a single oligo-astheno-teratozoospermic man. We bioinformatically demonstrated that the p.Arg246His substitution causes a decrease in the positive charge of this domain, potentially altering RNA-binding. Conclusions This is the first report describing the association of NANOS1 gene mutations with human infertility. Two different infertility phenotypes may reflect distinct functions of N-terminal versus C-terminal regions of NANOS1.


The European Journal of Contraception & Reproductive Health Care | 2013

Factors influencing women's selection of combined hormonal contraceptive methods after counselling in 11 countries: results from a subanalysis of the CHOICE study.

Johannes Bitzer; Vladimir Cupanik; Tomas Fait; Kristina Gemzell-Danielsson; Paul Grob; Björn J. Oddens; Leszek Pawelczyk; Vít Unzeitig

Abstract Objectives To investigate which characteristics of women and healthcare professionals (HCPs) were associated with changing to another combined hormonal contraceptive (CHC) method after contraceptive counselling. Methods CHOICE was a cross-sectional survey in which 18,787 women were counselled about combined hormonal contraceptives, during which their contraceptive methods preferred both prior to and after counselling were recorded. In this subanalysis, characteristics associated with changing the method after counselling were determined using logistic regression models. Results The probability of intending to change from the pill to another method was associated with being older; university-educated; being in a steady relationship; a prior unintended pregnancy; a younger HCP or one who recommended methods other than the pill. Changing to the patch was associated with a female HCP or a HCP who recommended the patch or an injectable. Changing to the ring was associated with being over 21 years; university-educated; being in a relationship; previous hormonal method use; and counselling by a female HCP, a HCP < 60 years old, or a HCP who recommended the ring or an implant. The country of residence influenced these changes in a complex pattern. Conclusions Womens choice of CHC methods after contraceptive counselling are influenced by their age, educational background, relationship status, prior unplanned pregnancies and country of residence, as well as age, gender and preferences of their HCP.

Collaboration


Dive into the Leszek Pawelczyk's collaboration.

Top Co-Authors

Avatar

Piotr Jedrzejczak

Poznan University of Medical Sciences

View shared research outputs
Top Co-Authors

Avatar

Robert Z. Spaczynski

Poznan University of Medical Sciences

View shared research outputs
Top Co-Authors

Avatar

Beata Banaszewska

Poznan University of Medical Sciences

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Katarzyna Ożegowska

Poznan University of Medical Sciences

View shared research outputs
Top Co-Authors

Avatar

Paweł P. Jagodziński

Poznan University of Medical Sciences

View shared research outputs
Top Co-Authors

Avatar

Jan Kotarski

Medical University of Lublin

View shared research outputs
Top Co-Authors

Avatar

Taszarek-Hauke G

Poznan University of Medical Sciences

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Anna Sokalska

University of California

View shared research outputs
Researchain Logo
Decentralizing Knowledge