The early history of estriol

The early history of estriol is reviewed with special emphasis on its isolation, identification, quantitation in tissues and body fluids and its unique biogenesis in the human feto-placental unit. The relationship to epimeric estriols and acidic estrogens and the pharmacokinetic and pharmacodynamic properties which led to a widespread therapeutic use of this compound are also discussed.     

Recent progress in polyamine research

Polyamines are recognized as cell growth factors in relation to cell proliferation, differentiation, regeneration and malignant transformation. Polyamines play an important role in the growth of normal cells like vascular endothelial cells and also exert various effects on the proliferation and metastasis of malignant cells. The recent studies on the biosynthesis have clearly elucidated its mechanism at the gane levels, which reflects to the development of the inhibitors of the polyamine biosynthesis. One of the main purposes of the studies on the various polyamine synthesis inhibitors is for the development of new anti-cancer agents, based on the characteristics of the polyamine functions. The clinical effects of several inhibitors, however, have not been shown to be satisfactory and the reason is now the most important research subject in this field. The measurement of the polyamine contents in biological fluids including urine and blood has been shown to be useful as the tumor marker. The recent studies have indicated that the mechanism of increased secretion of urinary polyamines is due to the release from the degraded cancer cells. The results now stimulated the research which aims to elucidate the usefulness of the measurement of urinary polyamines as the parameters of the sensitivity to the anticancer drugs in patients with cancer.     

The history of early cereal cultivation in northernmost Fennoscandia as indicated by palynological research

The age of the introduction of cereal cultivation in northern Europe has long been debated by researchers from many disciplines, in particular archaeology and palaeoecology. Over the past 40 years extensive palynological data have been collected concerning pre-industrial land use in northern Fennoscandia. This paper reviews palynological studies that include records of fossil cereal pollen from northernmost Sweden, Finland and Norway at latitudes north of 63°N. The geographical extent of known early cultivation sites is constantly expanding, with more than 100 records of cereal pollen pre-dating ad 1700. The oldest records of scattered cereal pollen derive from Neolithic times. Periods of continuous cultivation, indicated by cereal pollen recorded recurrently in the sediment profiles, derive from the Late Neolithic and Early Bronze Age. Collectively, the reviewed pollen records indicate that cereal cultivation was first introduced into areas close to the coast and later to the interior, and that it may have been practiced locally long before sedentary settlements based on intensive cultivation were established during medieval times. The data do not indicate a latitudinal spread of cultivation from south to north. However, methodological problems relating to pollen morphology of cereals, site characteristics and lack of connections to archaeologically excavated sites imply that the value of many early cereal pollen finds remains unclear. To increase our understanding of the context in which cereal cultivation was introduced in northernmost Fennoscandia, multidisciplinary studies integrating palaeoecology, archaeology and history are needed.     

Advances in polyamine research in 2007

Polyamines are small aliphatic amines found in all living organisms except some Archaea. In plants, putrescine, spermidine, and spermine are major components which are not only involved in fundamental cellular processes, for example cell proliferation, differentiation, and programmed cell death, but also in adaptive responses to environmental stress. In this article we review plant polyamine research focusing on recent studies.     

柽柳科（Tamaricaceae）植物的研究历史

柽柳科（Tamaricaceae)是一个古老的科,起源于第三纪,包括亚洲中部的内的“古地中海”沿岸地区,该科植物主要为旱生植物,其中大多数种是防风、固沙造林和水土保持的优良树种,对改造沙漠和改善气候条件具有重要的生态意义。同时,该科植物在荒漠地区还具有广泛的经济用途。     

The origin and early evolutionary history of amniotes

Recent phylogenetic analyses of Paleozoic tetrapods have yielded startling new insights into the origin and early evolutionary history of amniotes. The origin of this successful group involves evolutionary innovations that are associated with the development of the cleidoic egg and related reproductive strategies, and are therefore not represented directly in the fossil record. Despite this obvious difficulty, recent studies have been able to distinguish Paleozoic amniotes from their anamniotic tetrapod relatives to determine major patterns of interrelationships.     

The history of research on white-green variegated plants

Plinius the Elder (23–79 A.D.) noted the existence of variegated varieties of ivy. But only subsequent to the middle of the last century, when botanists detected chloroplasts and began to study their origin, did variegation of leaves begin to be investigated scientifically. The white, yellow, or yellow-green parts of the many species of variegated leaves contain either leucoplasts, plastids in various stages of degeneration leading to their complete disappearance, or plastids containing only carotene or xanthophyll. In some cases normal and abnormal plastids are found together in “mixed” cells. In some cases the variegation is temperature and/or light sensitive.     

The controversy on the early history of Chagas disease

Recently historians of medicine have proposed three distinctive accounts of early history of Chagas disease (American trypasonomiasis). According to the first the disease, described by the Brazilian researcher Carlos Chagas in 1909, was "deconstructed" in the 1920s and disappeared for about twenty years, then was recovered in the 1940s, mainly through the epidemiological studies of Emmanuel Dias and his colleagues in Minas Gerais (Brazil). According to the second Chagas disease could not be "deconstructed" in the 1920s because it did not exist at that time. Chagas observations were inaccurate and unreliable and did not define a new human pathology. The entity called today "Chagas disease" appeared in the 1930, principally as the result of investigations of Cecilio Roma?a in Argentina. Finally, a third view assumes that "Chagas disease" was constructed gradually between 1909 and the 1950s through the collective efforts of numerous Latino-American researchers. This paper juxtaposes different histories of Chagas disease, and argues that their divergences stems from allegiance to distinct, partly incommensurable epistemological "thought styles". The co-existence of divergent styles of historical investigation, this text proposes, should be perceived as potential source of enrichment of our understanding of the past.