Nephrology is one of the fields of internal medicine that became independent in the 1950s and 1960s (1). It is worth recalling that the great precursors of Polish nephrological thought, such as Jakub Penson or Jan Roguski, still considered themselves to be internists rather than nephrologists (2, 3, 4). The only person from this generation who did not have such doubts was Zdzisław Wiktor, who was the first in Poland and one of the first in Europe to establish a nephrology clinic in 1958 in Wrocław (1). He simultaneously entitled his work „Zarys Nefrologii Klinicznej” („An Outline of Clinical Nephrology”) (5). In other academic centres nephrology clinics appeared in the 1970s and 1980s. They were founded by such excellent clinicians as F. Kokot in Katowice, Z. Hanicki in Kraków, K. Bączyk in Poznań, A. Wojtczak in Lublin, A. Manitius in Gdańsk, M. Myśliwiec in Białystok, and others (1, 6, 7, 8). A prominent role in the development of nephrological thought was played by the Nephrology Board of the Clinical Pathophysiology Committee of the 6^th Department of the Polish Academy of Sciences, which was headed for many years by Prof. Tadeusz Orłowski (9). Not until 1983 was the Polish Society of Nephrology (Polskie Towarzystwo Nefrologiczne – PTN) initiated, beginning the slow but systematic march of Polish nephrology to the international salons. The first president of PTN was T. Orłowski, and his successors were, in order: K. Bączyk, F. Kokot, B. Rutkowski and currently A. Więcek (1, 7, 10). Together with the development of clinical nephrology in the last 20 years also dynamic progress in renal replacement therapy has occurred (11, 12, 13). Since the beginning of this century, no patients with terminal renal failure are left without access to this form of therapy (13, 14). The treatment techniques initiated and used in nephrology have applications in other fields of medicine, such as anaesthesiology and intensive therapy, clinical toxicology, hepatology, transplantology and cardiology (15-21). Therefore it is nothing unusual that Franciszek Kokot stated in one of his articles that: "nephrology is the flywheel of contemporary medicine” (22). Bearing this in mind, it would be worth assessing the current scientific position of Polish nephrology, which is precisely the aim of the present study.

Data presented in this publication derive from statistical surveys carried out in academic nephrology centres on the order of the Executive Board of the Polish Academy of Sciences for the period 2005-2009. A questionnaire specially developed for this purpose was sent out to 24 centres (17 clinics of adult nephrology and 7 clinics of paediatric nephrology), and completed forms were received from 19 clinics. Data listed in tables are in the form of overall or mean results and are anonymous, with no possibility to identify the individual centres that took part in the research. Additionally, for comparison four leading centres from Western Europe ( Copenhagen, Denmark; Paris, France; Aachen, Germany; Pavia, Italy) and Central and Eastern Europe ( Zagreb, Croatia; Prague, Czech Republic; Bucharest, Romania; Budapest, Hungary) were chosen at random. From the bibliometric database Medline publications from the same time period were chosen.

It should be stated on the basis of the presented data that the general condition of Polish nephrology is very good. This opinion is based on the number of publications, in particular those published in medical journals listed on the ISI Master Journal List, as well as on commonly used bibliometric indicators (tab. 1). Of course, as is always the case, there is large variation between individual units. There is a group of leaders who publish a lot and whose papers are accepted for publication in prestigious journals. Conversely there are also, as the presented data show, weak centres in which the scientific research activity is still not at an appropriate level. Assuming an arbitrary division based on the number of publications, four centres can be counted among the leading group responsible for over 200 publications in the assessed period of time. In seven others the number of publications is within 100-200 titles. In the other eight centres fewer than 100 papers were published in this period. It is worth adding that two of the respondent centres achieved in this period an Impact Factor value above 200, and four others report an IF exceeding 100. Parallel to the number and value of the publications is the number of citations, which additionally proves the recognition of our community at an international level. Moreover, it should be stated once again on the basis of the mean values that the situation in Polish nephrology centres is comparable within this scope with numerous renowned similar centres in Europe and worldwide. It should be added that a large majority of the publications in question were based on studies performed in Poland. However, they have a certain surplus value because they were undoubtedly achieved with the use of significantly smaller financial outlays. This may be confirmed by comparing the described results with data from the leading European centres, presented in table 2. It is worth adding that the level of Polish nephrology represented by papers published in prestigious journals indeed does not differ from that presented by our friends from Eastern as well as Western Europe. And, what is more, many leading Polish nephrology centres demonstrate a clear advantage in this scope. Also gratifying should be the fact that Polish paediatric nephrology centres perform excellently in scientific and research activity. Their achievements do not differ from those of the adult nephrology centres, which proves very well the constant progress that can be observed in this specific branch of paediatrics. The value of publications from the Polish nephrology centres is confirmed not only by the fact of their appearance in prestigious journals of high impact. It is crucial that they bring a whole range of insights helping to unravel the secrets of epidemiology, pathophysiology and clinical aspects of chronic kidney disease, and many specific diseases of this organ, as can be appreciated in the case of several publications chosen as examples (23-28). Additionally, the frequency of presentations during medical conventions, congresses and conferences that affect the Polish nephrological community were analysed. The numerous invitations to present guest lectures reflect particularly well the state of the Polish nephrological community. It is also worth mentioning that representatives of Polish nephrology have regularly been invited to participate in the scientific committees of conventions and congresses of European and world renown. However, it is also worth paying attention to the numerous oral and poster reports. It is particularly important that a strict selection of reports submitted for international conventions and conferences be carried out. As an instance, Poland has been one of the foremost countries that sends and presents papers for the Congresses of the European Renal Association–European Dialysis and Transplant Association. It is also worth bringing to attention the fact that our nephrology centres are more and more frequently entrusted with the organization of international conferences and conventions (29, 30). An additional argument concerning the international recognition for the position of Polish nephrologists is their participation in the work of bodies managing European or world scientific societies and their membership of editorial boards of prominent medical journals (tab. 3). Participation in such bodies is based on selection by the international members, which proves the thesis about the recognition of the Polish nephrological community at the world level. The range of international journals presented in table 4, in which Polish nephrologists are invited to review submitted papers, is additional proof of the above statements. All the above achievements are a credit to the hard work of the whole nephrological community within the last 20-25 years. It is worth recalling that still in the 1980s only isolated papers by Polish authors appeared in international journals. In many cases such publication was the result of participation by Polish nephrologists receiving academic training in leading world centres. Currently, young people from various parts of the world are applying for the chance to take part in such academic training courses in Polish centres.

To conclude, I would like to reiterate that the condition of the Polish nephrological community within scientific research activity is highly satisfactory. However, it could be even better if the financing of Polish research activity was provided at a level comparable with the developed European and world countries. Meanwhile, in reference to the title of this study, one can state without any exaggeration that Polish nephrology has grown from the Cinderella of the 1960s and 70s to a beautiful Royal Princess having pride of place at the court of the Queen of medical sciences, who is undoubtedly Internal Medicine.