We Dance round in a Ring and Suppose, but the Secret Sits in the Middle and Knows. Robert Frost Contemporary Neurotrophic Factor Research: towards a More Human Paradigm

The nerve growth factor (NGF) has been discovered by Rita Levi-Montalcini in the early 1950's (1,2). This paradigmic cell growth factor has gradually attracted the attention of many investigators from all over the world. In the very beginning, experimental research prevailed taking into consideration the still rather fundamental approach to the possible role of NGF and the subsequently discovered other neurotrophic factors in the living organism. Later on, an increasingly stable orientation of the scientific community towards the human beings, including a more outlined clinical research policy, has been emerging. Modern computerized scientometrics is capable of identifying not only the most essential communication patterns of the uninterrupted advancement of science in broader or narrower fields but also of demonstrating the role of different, relatively objective indicators and their constellations for the effective management of individual and collaborative research activity at local, regional, national and even international level (3-7). In order to reveal the extent of humanization, maturity, and scientific critique in the field of "nerve growth factors", a comprehensive bibliometric study of the publication activity in MEDLINE on CD-ROM through EBSCO Publ. during the period from 1966 till 1999 has been carried out. A set of the following main parameters have been examined: number of publications; number of authors per paper, number of reviews and letters; language of articles; number of papers dealing separately with animals and humans, and in combination of both. There is a dramatic increase of the number of publications in the last two decades. It should be noted that the descriptor "nerve growth factor" (NGF) first occurred in MESH of Index Medicus (National Library of Medicine, Bethesda, MD, USA) in 1972. In 1980, however, this descriptor was replaced by "nerve growth factors". Meanwhile, the family of neurotrophins rapidly enlarged and included a series of definitive items such as brainderived neurotrophic factor, neutrophin-3 (NT-3), NT-4/ 5, NT6, and NT-7. There are several factors exerting a neurotrophic effect such as ciliary-derived neurotrophic factor, glial cell line-derived neurotrophic factor, stem cell factor, hepa-tocyte growth factor, leukemia inhibitory factor, insulin-like growth factor, interleukin-3, -6, etc (see this volume of Bio-medical Reviews). During the aforementioned period, a total of 9465 publications have been retrieved in MEDLINE on CD-ROM. There are a total of 9120 papers (96.35 % of the publications) published in English, 1092 reviews (11.53 %), and 57 letters to the editor (0.6 %). In 1966-1969, there are a total of 87 papers only. Interestingly, already in the next decade (1970-1979), the number of papers dramatically increases up to 659. This exponential growth tendency persists in the next decades: in 1980-1989, 1963 papers and in 1990-1999, 6756 papers have been published. Besides there is a stable augmentation of the relative share of the English language articles: from 82.76 % in 1966-1969 to 93.62 % in 1970-1979 and from 94.91 %in 1980-1989 to 97.22%in 1990-1999 (p < 0.001). The statistically significant rate of growth (p < 0.01) of the total number of publications on NGF and of those in English during the last decades is illustrated on Figure 1.