Loneliness and Coping Styles Among Athletes With Disabilities During the COVID-19 Pandemic.

The study aimed to assess loneliness experiences among athletes with disabilities (AWD) during the different phases of the pandemic and to understand its relationship with coping styles. Ninety-one AWD participated in a longitudinal study spanning 10 months, covering three time points: April (A), June (Time B), and November (Time C) 2021. The study used the Coping Inventory for Stressful Situations and the revised University of California Los Angeles Loneliness Scale-Revised (UCLA-R) to measure coping mechanisms and feelings of loneliness, respectively. Loneliness levels peaked during the most intense phase of the pandemic, showing significant differences between consecutive time points (χ2 = 20.29, p < 0.001, d = 0.24). The most robust regression models were built in Time B, using the "intimate contacts" dimension of loneliness as the dependent variable and "emotion-oriented coping", "avoidance-oriented coping", and "impairment" as independent variables, explaining 44% of the variance (p < 0.001). Loneliness among Paralympic athletes fluctuated during various phases of the pandemic. The findings highlight the significant influence of coping styles, particularly emotional styles which heightened perceived loneliness, and task-oriented styles which reduced it, on athletes' experiences of loneliness. These results underscore the need for longitudinal studies to delve deeper into the relationship between loneliness and mental health. Moreover, they stress the importance of developing tailored interventions that promote effective coping mechanisms in AWD during challenging times amid to COIVID-19.

Small cell carcinoma with neuroendocrine differentiation of subglottic larynx- a case report.

Small cell cancer (SCC) is a neuroendocrine neoplasm, which is most frequently found in the lungs. Extrapulmonary location of SCC is rare and may involve 2.5-5% of SCCs. We present a case of a 31-year-old male patient with an extremely uncommon subglottic SCC. The patient was qualified for a radical sequential chemoradiotherapy. After treatment, patient's condition suggested complete remission. Recurrence was detected one year later, and the disease rapidly progressed, despite a second line chemotherapy. The patient died 29 months after initial diagnosis. This case aims to raise awareness on the aggressive laryngeal SCC and its good response to first line chemotherapy composed of cisplatin and etoposide, followed by radiotherapy.

Intracellular tPA-PAI-1 interaction determines VLDL assembly in hepatocytes.

Apolipoprotein B (apoB)-lipoproteins initiate and promote atherosclerotic cardiovascular disease. Plasma tissue plasminogen activator (tPA) activity is negatively associated with atherogenic apoB-lipoprotein cholesterol levels in humans, but the mechanisms are unknown. We found that tPA, partially through the lysine-binding site on its Kringle 2 domain, binds to the N terminus of apoB, blocking the interaction between apoB and microsomal triglyceride transfer protein (MTP) in hepatocytes, thereby reducing very-low-density lipoprotein (VLDL) assembly and plasma apoB-lipoprotein cholesterol levels. Plasminogen activator inhibitor 1 (PAI-1) sequesters tPA away from apoB and increases VLDL assembly. Humans with PAI-1 deficiency have smaller VLDL particles and lower plasma levels of apoB-lipoprotein cholesterol. These results suggest a mechanism that fine-tunes VLDL assembly by intracellular interactions among tPA, PAI-1, and apoB in hepatocytes.

Polish adaptation of multisource assessment of children's social competence.

This study aimed to adapt the Multisource Assessment of Social Competence Scale for the Polish population. The population examined in the study included only Polish participants of European (Caucasian) ancestry. The tool is composed of two scales, Prosocial and Antisocial, and four subscales. For the purpose of adaptation, children's social competence was evaluated based on their own and their parents' perspective. The sample consisted of children aged 9-15 (n = 253) and their parents (n = 248), with boys and girls accounting for 43% (n = 109) and 57% (n = 144) of child participants, respectively. All the participants originated from the western-central Greater Poland Voivodeship. The data analyzed in this study were collected in 2019. Internal consistency of the subscales and correlation between them were measured using Cronbach's Alpha reliability coefficient and Spearman's correlation coefficient, respectively. Confirmatory factor analysis was conducted for both groups (children and parents) in two-, three- and four-factor models. The confirmatory factor analysis for both groups (children and parents) attributed the four-factor model with the highest goodness-of-fit, fulfilling the criteria of a good-fitting model. The results show that the Multisource Assessment of Children's Social Competence Scale is an appropriately adapted tool for the evaluation of the social competence of children in Poland, taking different rater perspectives into account.

Frequency of COVID-19 Infection as a Function of Vitamin D Levels.

BACKGROUND: It has been speculated that higher concentrations of 25-hydroxy-vitamin D (25OHD) provide some protection against COVID-19. We assessed whether there is any relationship between 25OHD concentrations and the subsequent development of COVID-19 infection. MATERIALS AND METHODS: Concentrations of 25OHD were measured in March-April 2020 in 134 healthy subjects (57 males), age range 6-50, from a single urban general practice in central Poland. Data on COVID-19 infection during the subsequent 12 months (prior to the vaccination program) were obtained from the national database of COVID-19 cases. None of the subjects received any 25OHD supplements. RESULTS: The average 25OHD concentrations were 18.1 ± 7.39 ng/mL (37.3% had 25OHD above 20 ng/mL). Thirty-one (23.1%) patients developed COVID-19 infection, but an increased risk was only observed in individuals with 25OHD concentrations below 12 ng/mL (COVID-19 infection in 11 out of 25 patients (44%) with 25OHD < 12 ng/mL versus 20 out of 109 (18.3%) for those with 25OHD above 12 ng/mL, p = 0.0063). Such a relationship was no longer observed for subjects with 25OHD concentrations above 20 ng/mL (p = 0.2787). CONCLUSIONS: Although only a minority of healthy subjects had 25OHD concentrations above 20 ng/mL in spring, an increased risk of subsequent COVID-19 infection was only observed in those with severe 25OHD deficiency (<12 ng/mL).

Global epidemiology of factor XI deficiency: A targeted review of the literature and foundation reports.

INTRODUCTION: Hereditary factor XI (FXI) deficiency is a rare coagulation disorder that may result in excessive bleeding requiring intervention to restore haemostasis. AIM: The aim of this review was to report the current knowledge of the worldwide incidence and prevalence of FXI deficiency. METHODS: A targeted PubMed search using terms related to FXI deficiency was conducted to identify studies published from April 2002 through April 2022. A manual search supplemented the electronic search. Studies were eligible for data abstraction if they reported population-based incidence proportions/rates or prevalence proportions for FXI deficiency. RESULTS: The electronic and manual searches returned 253 publications. After applying exclusion criteria, seven publications were included in the analysis, including a global report from the World Federation of Haemophilia (WFH). Six publications provided information on the prevalence of FXI deficiency that included 74 countries and regions. The estimated prevalence of FXI in the WFH report ranged from 0/100,000 in several countries to 55.85/100,000 individuals in the United Kingdom. Prevalence estimates in the PubMed findings ranged from .1 to 246.2/1,000,000 inhabitants with varying methods of case identification and time periods of analysis. One study estimated the incidence of FXI deficiency in Yecla, Spain at 2% of blood donors and .09% of hospital inpatients/outpatients with activated partial thromboplastin time (aPTT) tests. CONCLUSION: FXI deficiency is rare across the world, but additional steps could be taken to improve incidence and prevalence estimation, for example, development of a consistent FXI deficiency definition and incorporating genetic testing into a clinical routine to better identify and characterise cases.

The effects of season (spring versus autumn) on diagnosis of normocalcemic primary hyperparathyroidism.

Background: Raised parathormone (PTH) and normal calcium concentrations can be observed both in normocalcemic primary hyperparathyroidism (nPHPT) and in secondary hyperparathyroidism, e.g. due to vitamin D deficiency. We assessed the impact of season on the validity of diagnosis of nPHPT in terms of screening investigations to be performed in the primary care settings. Material and methods: On two occasions (March/April & September/October) we measured vitamin D (25OHD), PTH and total calcium in 125 healthy subjects, age range 6-50, not taking any vitamin D supplements. Results: In autumn there was an increase in 25OHD concentrations (from 18.1 ± 7.37ng/ml to 24.58 ± 7.72ng/ml, p<0.0001), a decline in PTH from 44.40 ± 17.76pg/ml to 36.63 ± 14.84pg/ml, p<0.001), without change in calcium levels. Only 45 subjects (36%) were vitamin D sufficient (25OHD>20/ml) in spring versus 83 (66.4%) in autumn, p<0.001. Elevated PTH concentrations were noted in 10 subjects in spring (8%) and in six subjects (4.8%) (p<0.05) in autumn. In spring, however, eight out of ten of these subjects (80%) had 25OHD<20 ng/ml, versus one in six (16.7%) in autumn (p<0.01). Normalization of PTH was observed in seven out ten subjects (70%), and all of them had 25-OHD<20 ng/ml in spring. Conclusions: In spring elevated PTH concentrations in the setting of normocalcemia are more likely to be caused by 25OHD deficiency rather by nPHPT. In contrast, in autumn, increased PTH concentrations are more likely to reflect nPHPT. We postulate that screening for nPHPT should be done in 25OHD replete subjects, i.e. in autumn rather than in spring.

Therapeutic and technological advancements in haemophilia care: Quantum leaps forward.

INTRODUCTION: Recent technological innovations in haemophilia have advanced at an astounding pace, including gene therapy programmes and bioengineered molecules for prophylaxis, products that reduce treatment burden through half-life extension, unique mechanisms of action, and subcutaneous administration. Additional technological advancements have emerged that are anticipated to further transform haemophilia care. AIM: Review new and emerging haemophilia therapies, including replacement and bypassing products, digital applications, utilisation of big data, and personalised medicine. METHODS: Data were obtained from peer-reviewed presentations/publications, and ongoing studies in haemophilia, ultrasonography, and artificial intelligence (AI). RESULTS: Available treatments include new recombinant factors VIII (FVIII) and IX (FIX), extended half-life FVIII/IX products, a new FVIIa product for inhibitor patients, and a FVIIIa-mimetic. Several novel therapeutics are in clinical trials, including FVIIIa mimetics and inhibitors of naturally-occurring anticoagulants. Ongoing gene therapy trials suggest that a single vector infusion using an optimised construct can produce factor activity that reduces bleeding to near zero for years. Today, persons with haemophilia (PwH) approach a lifespan comparable to that of the general population, presenting treatment challenges for age-related co-morbidities. Technological innovations have broadened beyond therapeutics to include large database analyses utilising remote data collection with handheld devices, and to tailor AI applications. Current development efforts include patient-performed ultrasonography, algorithms for scan interpretation, and point-of-care haemostatic testing devices. CONCLUSIONS: We have entered a golden age for haemophilia treatment and care with wide-ranging advancements targeting improved quality of life (QoL). Future-focused efforts by clinical and patient communities may provide equitable access and care for people impacted by haemophilia worldwide.

What Should Be the Topics of a Prospective Study on Ovarian Masses in Children?-Results of a Multicenter Retrospective Study and a Scoping Literature Review.

PURPOSE: to determine management problems of ovarian masses in girls in order to form a baseline for prospective randomized studies of the established topics and quality improvement of our management. MATERIALS AND METHODS: We performed a national analysis of clinical aspects of ovarian masses in girls operated on in Poland, analyzed retrospectively medical files of all consecutive patients aged 0-18 who underwent surgeries for ovarian lesions between 2012 and 2017 at 17 pediatric surgical departments and complemented the analysis with a scoping review of a recent primary research related to ovarian masses in children. RESULTS: The study group comprised 595 patients. Forty-four (7.39%) girls were diagnosed with malignant tumors. The overall preservation rate was 64.54%. The analysis revealed that positive tumor markers (OR = 10.3), lesions larger than 6 cm (OR = 4.17) and solid mass on ultrasound examination (OR = 5.34) are interdependent variables differentiating malignant tumors from non-malignant lesions (X42 = 79.1; p = 0.00000). Our scoping review revealed 10 major branches of research within the topic of ovarian masses in pediatric population. CONCLUSIONS: We have developed an overview of the field with the emphasis on the local environment. Our next step is a multi-institutional prospective study of a quality improvement project implementation based on the obtained knowledge.

WHO collaborative registration procedure using stringent regulatory authorities' medicine evaluation: reliance in action?

INTRODUCTION: The regulatory approval of medical products in countries with limited regulatory resources can be lengthy, which often compromises patients' timely access to much-needed medicines. To improve the efficiency of regulatory systems, reliance is being used. Reliance allows an authority to leverage the work performed by other authorities, such as scientific evaluations, to decide on medical products approval within their jurisdiction. This reduces duplication of regulatory efforts, resources and time, while maintaining national sovereignty. AREAS COVERED: This article analyzes the outcomes and stakeholders' experience of using medicines assessments performed by Stringent Regulatory Authorities (SRA) in the Collaborative Registration Procedures (CRP). Since its establishment in 2015, 59 approvals were granted to 16 medicines in 23 countries through SRA CRP. Results show that the procedure is delivering on the intended benefits of access and speed, with long-term positive impact for resource-limited countries. The article concludes with recommendations on the need for guidance on management of post-approval changes, wider promotion of the procedure, and increased collaboration between authorities. EXPERT OPINION: The SRA CRP provides a mechanism for the use of reliance by strengthening communication and promoting the exchange of information among regulators. This fosters faster regulatory approvals and, consequently, earlier access to medicines.

Factor XI Deficiency.

Factor XI (FXI) deficiency (hemophilia C or Rosenthal disease) was first described in the 1950s in a multigenerational family experiencing bleeding related to surgery and dental procedures. Managing patients with FXI deficiency presents several challenges, including a lack of correlation of bleeding symptoms with FXI activity levels, the large volume of fresh frozen plasma required to achieve hemostatic FXI levels, lack of availability of FXI concentrate in certain regions of the world, and the inherent thrombotic risk associated with replacement therapy. This article summarizes presentation, diagnosis, and management of patients with FXI deficiency in a variety of clinical settings.

Effect of Summer Sunshine Exposure on Vitamin D Status in Young and Middle Age Poles: Is 30 ng/mL Vitamin D Cut-Off Really Suitable for the Polish Population?

BACKGROUND: There is no consensus regarding vitamin sufficiency status with either 20 ng/mL or 30 ng/mL sufficiency cut-off. We assessed the effects of summer sunshine exposure on vitamin D status. PARTICIPANTS: We measured vitamin D concentrations, PTH, creatinine, and total calcium in 132 healthy subjects, age 29.36 ± 13.57 years, in spring and autumn. RESULTS: There was an overall increase in vitamin D concentrations from spring to autumn from 18.1 ± 7.39 ng/mL to 24.58 ± 7.72 ng/mL, (p < 0.001), accompanied by a decrease in PTH from 44.4 ± 17.76 pg/mL to 36.6 ± 14.84 pg/mL, (p < 0.001). In spring, only 5.3% of individuals were vitamin D sufficient for a 30 ng/mL cut-off, increasing to 23.2% in autumn (p < 0.001). In contrast, when a 20 ng/mL cut-off was employed, vitamin D sufficiency was found in 34.1% in spring and 66.4% individuals in autumn, respectively, (p < 0.001). In multiple regression analysis, holiday leave was the only significant determinant of vitamin D increase (p < 0.001). CONCLUSIONS: Holiday leave is the strongest determinant of an increase in vitamin D. The majority of healthy individuals fail to reach a 30 ng/mL vitamin D cut-off after summer sunshine exposure. This raises the question, whether such a cut-off is indeed suitable for the Polish population.

Molecular classification of glioblastoma based on immunohistochemical expression of EGFR, PDGFRA, NF1, IDH1, p53 and PTEN proteins.

Glioblastoma (GBM) is the most common and most aggressive primary tumor of the central nervous system. Current GBM treatments have low effectiveness. This is mainly due to the high degree of heterogeneity of GBM tumors. Despite similarities in the classic microscopic image, these tumors differ significantly in molecular terms. The aim of the study was to classify GBM tumors into one of four molecular types based on the immunohistochemical expression of EGFR, PDGFRA, NF1, IDH1, p53 and PTEN proteins and find the association between individual glioma molecular types and prognostic clinical and morphological parameters. From the group of 162 patients the classical molecular type of tumor was observed in 17 (10%) patients, in 23 (14%) the tumor was mesenchymal, in 32 (20%) proneural, and in 90 (56%) neural. No significant relationship was observed between the molecular type of GBM tumors and the studied clinical and morphological parameters of prognostic significance. There were also no statistically significant correlations between the GBM tumor molecular type and survival, both in terms of overall survival and relapse-free survival. Analyzing the impact of all prognostic variables and molecular type of GBM on the probability of overall survival, statistically significant relationships were found.

Management of people with haemophilia A undergoing surgery while receiving emicizumab prophylaxis: Real-world experience from a large comprehensive treatment centre in the US.

INTRODUCTION: Surgery is frequently required in persons with haemophilia A (PwHA). Emicizumab, a bispecific, humanized monoclonal antibody, bridges activated factor (F) IX and FX. Management of patients undergoing surgery while receiving emicizumab is of clinical interest due to paucity of data. AIM: Review real-world experience of PwHA with/without FVIII inhibitors who required surgery while receiving emicizumab prophylaxis. METHODS: Data regarding peri-operative management, including type of surgery, haemostatic agent use and bleeding complications, were collected for PwHA receiving emicizumab undergoing surgery between 25/10/18 and 31/12/19 at the Indiana Hemophilia and Thrombosis Center. Analyses were exploratory and descriptive. RESULTS: Twenty minor and five major surgeries were performed in 17 and five patients, respectively. Overall, 9/20 minor surgeries were planned to occur with emicizumab as the sole haemostatic agent; of these, four required additional coagulation factor (2 due to haematomas following port removals, 1 due to oozing at port removal site, 1 due to bleeding following squamous cell carcinoma removal). Three of the 11 minor surgeries with planned additional coagulation factor resulted in non-major bleeds; all were safely managed with additional coagulation factor. All five major surgeries were planned with additional haemostatic agents; there was 1 bleed in a patient undergoing elbow synovectomy with nerve transposition, likely triggered by physical/occupational therapy. There were no major bleeds, thrombotic events or deaths. CONCLUSIONS: Additional haemostatic agent use is safe in PwHA undergoing surgery while receiving emicizumab. Additional data are needed to determine the optimal dosing/length of treatment of additional haemostatic agents to lower bleeding risk.

Nucleolin and nucleophosmin expression patterns in pulmonary adenocarcinoma invading the pleura and in pleural malignant mesothelioma.

BACKGROUND: Visceral pleural invasion (VPI) in adenocarcinoma of the lung is considered a poor prognostic factor. The purpose of this study was to analyze nucleolin and nucleophosmin expression in pulmonary adenocarcinoma (PA) with VPI and in pleural malignant mesothelioma. METHODS: The study was conducted on the basis of 19 pathologically-confirmed cases of adenocarcinoma of the lung and 29 cases of epithelioid malignant mesothelioma. The nucleolin and nucleophosmin expression was assessed immunohistochemically and analyzed with image analysis software. RESULTS: Nucleolin expression was lower while nucleophosmin was higher in pleural invasion of pulmonary adenocarcinoma than in the central part of the tumor. Differences in subpopulations of cells with different expression of proteins studied were also found. Malignant mesothelioma showed lower nucleolin expression than adenocarcinoma of the lung but no differences in nucleophosmin expression were found. CONCLUSIONS: The results of our study suggested that lower nucleolin and higher nucleophosmin expression may be related to higher invasiveness of adenocarcinoma of the lung. Differences in nucleolin expression between pulmonary adenocarcinoma and malignant mesothelioma indicate another aspect of biology of these pleura-invading cancers that requires further study. KEY POINTS: SIGNIFICANT FINDINGS OF THE STUDY: Differences in nucleolin and nucleophosmin expression in pleura invading pulmonary adenocarcinoma indicate the involvement of these proteins in its locoregional spread while differences in nucleolin expression between pulmonary adenocarcinoma and malignant mesothelioma suggest another aspect of biology of these cancers. WHAT THIS STUDY ADDS: This is the first study on nucleolin and nucleophosmin expression in pleural malignant mesothelioma and pleura-invading pulmonary adenocarcinoma. Our findings may assist in understanding the mechanisms of locoregional spread of adenocarcinoma and differences between these two pleura-invading cancers.

Adequate timing and constant supervision are the keys for successful implementation of levothyroxine or levothyroxine/paracetamol absorption test.

BACKGROUND: Levothyroxine (LT4) pseudomalabsorption due to medication non-adherence results in significant costs for Health Service. High dose LT4 or LT4/paracetamol absorption test is used in such cases. Hence, establishment of an optimal test protocol and timing of sample collection is of utmost importance. CASE PRESENTATION: A 34-year old woman was admitted to our Department because of severe hypothyroidism [on admission thyrotropin (TSH) > 100 µIU/ml, free thyroxine (FT4) 0.13 ng/dl (ref. range 0.93-1.7)] despite apparently taking 1000 µg of LT4 a day. Autoimmune hypothyroidism had been diagnosed 4 years before during post-partum thyroiditis. Subsequently, it was not possible to control her hypothyroidism despite several admissions to two University Hospitals and despite vehement denial of compliance problems. There was no evidence of coeliac disease or other malabsorption problems, though gluten-free and lactose-free diet was empirically instigated without success. A combined paracetamol (1000 mg)/LT4 (1000 µg) absorption test was performed in one of these Hospitals. This showed good paracetamol absorption (from < 2 µg/ml to 14.11 µg/ml at 120 min), with inadequate LT4 absorption (FT4 increase from 5.95 pmol/l to 9.92 pmol/l at 0 and 120 min respectively). About 2 years prior to admission to our Department the patient was treated with escalating doses of levothyroxine [up to 3000 µg of T4 and 40 µg of triiodothyronine (T3) daily] without significant impact on TSH (still > 75 µIU/ml, and FT4 still below reference range).After admission to our Department we performed a 2500 µg LT4 absorption test with controlled ingestion of crushed tablets, strict patient monitoring and sampling at 30 min intervals. We observed a quick and striking increase in FT4 from 0.13 to 0.46, 1.78, 3.05 and 3.81 ng/dl, at 0, 30, 60, 90 and 120 min, respectively. Her TSH concentration decreased to 13.77 µIU/ml within 4 days. When informed, that we had managed to "overcome" her absorption problems, she discharged herself against medical advice and declined psychiatric consultation. CONCLUSIONS: Adequate patient supervision and frequent sampling (e.g. every 30 min for 210 min) is the key for successful implementation of LT4 absorption test. Paracetamol coadministration appears superfluous in such cases.

Nucleolin and Nucleophosmin Expression in Gleason 3 and Gleason 4 Prostate Cancer With Seminal Vesicles Invasion (pT3b).

BACKGROUND/AIM: The aim of this study was to analyze the expression of nucleolin (NCL) and nucleophosmin (NPM) in prostate adenocarcinoma and in its loco-regional spread in the form of seminal vesicle invasion (SVI). MATERIALS AND METHODS: The study was performed on tissue microarrays of 40 cases of Gleason 3+4 pT3b prostate cancers including tissue samples from SVI. The expression of NCL and NPM was detected immunohistochemically and analyzed with image analysis software. RESULTS: The expression of NCL and NPM were higher in cancer cells within a prostate gland than in SVI. Gleason 4 pattern showed higher expression of NPM than Gleason 3 pattern cells. CONCLUSION: Differences in nuclear NCL and NPM expression in cancer cells between the prostate gland and SVI may indicate involvement of these proteins in loco-regional spread of adenocarcinoma of the prostate. Differences in NPM expression in Gleason 3 and Gleason 4 pattern suggest involvement of this protein in the differentiation of prostate cancer.

Anti-Pr antibody induced cold autoimmune hemolytic anemia following pneumococcal vaccination.

While rare, vaccination-induced autoantibodies can occur outside of the pediatric population. This diagnosis should be considered after infectious and lymphoproliferative disorders are ruled out. Clinical management will depend on the individual case, but all patients should be monitored closely.

Nucleolin and nucleophosmin expression in seminomas and non-seminomatous testicular tumors.

INTRODUCTION: Testicular tumors are heterogeneous group of neoplasms divided mainly into two types: seminomas and non-seminomas. Nucleolin (NCL) and nucleophosmin (NPM) are abundant nucleolar proteins involved in many physiologic and pathologic processes including cancer. Their overexpression was found in many tumors but it was not studied in testicular cancer. MATERIAL AND METHODS: The study was performed on tissue microarrays of 19 seminomas, 21 embryonal carcinomas and 11 yolk sac tumors. The expression of NCL and NPM was detected with monoclonal antibodies and visualized with EnVision FLEX/HRP technique. Immunohistochemical reactions were measured with Aperio ImageScope Software and analyzed as means of percentages of all immunopositive cells in three groups of reaction intensity, i.e. 3+, 2+, and 1+ as well as of H-score. RESULTS: Seminomas showed higher expression of nucleolin indicated by higher H-score and higher percentage of positive cells than non-seminomas. The differences in subpopulations of NCL-positive cells were also found. Embryonal carcinomas and yolk sac tumors showed lower expression of NCL than seminomas indicated by H-score. The percentage of NCL-positive cells did not differ between embryonal carcinomas and seminomas while there were significant differences in subpopulations of cells. The percentage of NCL-positive cells in yolk sac tumors was lower than in seminomas. The results show different heterogeneity of subpopulations of NCL-positive cells in embryonal carcinomas and yolk sac tumors compared to seminomas. The analysis of nucleolin expression in embryonal carcinomas and yolk sac tumors showed no differences between these two tumor types. No differences in nucleophosmin expression between seminomas and non-seminomas were found. CONCLUSIONS: The differences in the expression of nucleolin between two groups of germ cell testicular tumors found in the current study indicate a new aspect of biology of these neoplasms and require further studies on the role of nucleolin in germ cell tumorigenesis.