Keijiro Samejima

2.2k total citations
123 papers, 1.9k citations indexed

About

Keijiro Samejima is a scholar working on Molecular Biology, Biochemistry and Pharmacology. According to data from OpenAlex, Keijiro Samejima has authored 123 papers receiving a total of 1.9k indexed citations (citations by other indexed papers that have themselves been cited), including 106 papers in Molecular Biology, 42 papers in Biochemistry and 15 papers in Pharmacology. Recurrent topics in Keijiro Samejima's work include Polyamine Metabolism and Applications (85 papers), Amino Acid Enzymes and Metabolism (42 papers) and Cannabis and Cannabinoid Research (15 papers). Keijiro Samejima is often cited by papers focused on Polyamine Metabolism and Applications (85 papers), Amino Acid Enzymes and Metabolism (42 papers) and Cannabis and Cannabinoid Research (15 papers). Keijiro Samejima collaborates with scholars based in Japan, United States and China. Keijiro Samejima's co-authors include Masaru Niitsu, Koei Hamana, Shigeru Matsuzaki, Akira Shirahata, Sidney Udenfriend, Wallace Dairman, Banri Yamanoha, M Kawase, Yasuko Takeda and Masashi Okada and has published in prestigious journals such as Journal of Biological Chemistry, Journal of Molecular Biology and Analytical Biochemistry.

In The Last Decade

Keijiro Samejima

118 papers receiving 1.7k citations

Peers — A (Enhanced Table)

Peers by citation overlap · career bar shows stage (early→late) cites · hero ref

Name h Career Trend Papers Cites
Keijiro Samejima Japan 23 1.5k 630 277 204 158 123 1.9k
Hans Ulrich Schairer Germany 28 2.3k 1.5× 222 0.4× 308 1.1× 82 0.4× 211 1.3× 67 2.9k
W H Kunau Germany 27 3.1k 2.0× 391 0.6× 153 0.6× 72 0.4× 168 1.1× 48 3.6k
Hirohiko Katsuki Japan 24 1.2k 0.8× 369 0.6× 136 0.5× 121 0.6× 151 1.0× 111 1.8k
Roderich Brandsch Germany 26 1.4k 0.9× 256 0.4× 81 0.3× 58 0.3× 157 1.0× 79 1.9k
Jonathan Jeffery United Kingdom 21 1.6k 1.1× 379 0.6× 172 0.6× 72 0.4× 225 1.4× 65 2.8k
Neal J. Stolowich United States 29 1.6k 1.1× 191 0.3× 133 0.5× 92 0.5× 164 1.0× 74 2.2k
Richard S. Schweet United States 31 2.0k 1.3× 234 0.4× 82 0.3× 137 0.7× 135 0.9× 54 2.7k
William K. Wilson United States 32 1.8k 1.1× 259 0.4× 324 1.2× 152 0.7× 141 0.9× 110 2.5k
H.V. Rickenberg United States 25 1.3k 0.9× 262 0.4× 95 0.3× 52 0.3× 117 0.7× 57 1.9k
Harold J. Strecker United States 23 1.2k 0.8× 623 1.0× 110 0.4× 90 0.4× 132 0.8× 56 1.9k

Countries citing papers authored by Keijiro Samejima

Since Specialization
Citations

This map shows the geographic impact of Keijiro Samejima's research. It shows the number of citations coming from papers published by authors working in each country. You can also color the map by specialization and compare the number of citations received by Keijiro Samejima with the expected number of citations based on a country's size and research output (numbers larger than one mean the country cites Keijiro Samejima more than expected).

Fields of papers citing papers by Keijiro Samejima

Since Specialization
Physical SciencesHealth SciencesLife SciencesSocial Sciences

This network shows the impact of papers produced by Keijiro Samejima. Nodes represent research fields, and links connect fields that are likely to share authors. Colored nodes show fields that tend to cite the papers produced by Keijiro Samejima. The network helps show where Keijiro Samejima may publish in the future.

Co-authorship network of co-authors of Keijiro Samejima

This figure shows the co-authorship network connecting the top 25 collaborators of Keijiro Samejima. A scholar is included among the top collaborators of Keijiro Samejima based on the total number of citations received by their joint publications. Widths of edges represent the number of papers authors have co-authored together. Node borders signify the number of papers an author published with Keijiro Samejima. Keijiro Samejima is excluded from the visualization to improve readability, since they are connected to all nodes in the network.

All Works

20 of 20 papers shown
1.
Kuwata, Go, Kyoko Hiramatsu, Keijiro Samejima, et al.. (2013). Increase of N 1 ,N 12-diacetylspermine in tissues from colorectal cancer and its liver metastasis. Journal of Cancer Research and Clinical Oncology. 139(6). 925–932. 18 indexed citations
2.
Samejima, Keijiro, et al.. (2012). A mass spectrometric method to determine activities of enzymes involved in polyamine catabolism. Analytica Chimica Acta. 748. 45–52. 9 indexed citations
3.
Stevens, Axel P., Katja Dettmer, Georgi Kirovski, et al.. (2010). Quantification of intermediates of the methionine and polyamine metabolism by liquid chromatography–tandem mass spectrometry in cultured tumor cells and liver biopsies. Journal of Chromatography A. 1217(19). 3282–3288. 35 indexed citations
4.
Ohnuma, Mio, Yusuke Terui, Masatada Tamakoshi, et al.. (2005). N1-Aminopropylagmatine, a New Polyamine Produced as a Key Intermediate in Polyamine Biosynthesis of an Extreme Thermophile, Thermus thermophilus. Journal of Biological Chemistry. 280(34). 30073–30082. 61 indexed citations
5.
Xu, Yong, Takeshi Hara, Keijiro Samejima, et al.. (2002). Simultaneous Determination of Endogenous and Orally Administered 15N-Labeled Polyamines in Rat Organs. Analytical Biochemistry. 301(2). 255–260. 11 indexed citations
6.
Xu, Yong, et al.. (2000). Measurements of Macromolecule-Bound and Ultra-Filtrable Polyamines in Rat Liver Homogenized without Buffer.. Biological and Pharmaceutical Bulletin. 23(9). 1021–1026. 3 indexed citations
7.
Takao, Koichi & Keijiro Samejima. (1999). Arginyl-tRNA-Protein Transferase Activities in Crude Supernatants of Rat Tissues.. Biological and Pharmaceutical Bulletin. 22(9). 1007–1009. 7 indexed citations
8.
Takao, Koichi, et al.. (1999). Preparation and Usefulness of Some Fluorogenic Substrates for Assay of Arginyl-tRNA-Protein Transferase by HPLC. Analytical Biochemistry. 267(2). 373–381. 1 indexed citations
9.
Xu, Yong, et al.. (1998). Ionspray Ionization–Mass Spectrometric Separation and Determination of Heptafluorobutyryl Derivatives of Polyamines. Analytical Biochemistry. 265(2). 253–259. 17 indexed citations
10.
Samejima, Keijiro, et al.. (1996). Determination of Covalently Bound Hypusine and Deoxyhypusine to Protein Using Submilligram of Protein Samples by HPLC.. Biological and Pharmaceutical Bulletin. 19(1). 1–5. 5 indexed citations
11.
Shirahata, Akira, et al.. (1995). Structural Requirement for Neurotrophic Activity of Spermine in Cultured Rat Hippocampal Neurons. The Japanese Journal of Pharmacology. 67(2). 173–176. 3 indexed citations
12.
Shirahata, Akira, et al.. (1995). Antagonistic Effect of N-(3-Aminopropyl)cyclohexylamine on Neurotrophic Action of Spermine in Primary Cultured Rat Hippocampal and Cerebellar Neurons. The Japanese Journal of Pharmacology. 69(4). 311–316. 4 indexed citations
13.
Niitsu, Masaru, et al.. (1995). Identification of N4-(2-Propenal)spermidine as a Major Reaction Product of Malondialdehyde and Spermidine.. Biological and Pharmaceutical Bulletin. 18(8). 1162–1164. 2 indexed citations
14.
Shirahata, Akira, et al.. (1993). Effects of inhibitors of spermidine synthase and spermine synthase on polyamine synthesis in rat tissues. Biochemical Pharmacology. 45(9). 1897–1903. 52 indexed citations
15.
Hamana, Koei, et al.. (1991). Polyamine Distributions in Thermophilic Eubacteria Belonging to Thermus and Acidothermus. The Journal of Biochemistry. 109(3). 444–449. 32 indexed citations
16.
Shirahata, Akira, et al.. (1991). Polyamine-linked sepharoses: Preparation and application to mammalian spermine synthase. Protein Expression and Purification. 2(4). 229–234. 4 indexed citations
17.
Shirahata, Akira, et al.. (1991). Putrescine or spermidine binding site of aminopropyltransferases and competitive inhibitors. Biochemical Pharmacology. 41(2). 205–212. 41 indexed citations
18.
Hamana, Koei, Masaru Niitsu, Keijiro Samejima, & Shigeru Matsuzaki. (1990). Thermopentamine, a novel linear pentaamine found inThermus thermophilus. FEMS Microbiology Letters. 68(1-2). 27–30. 10 indexed citations
19.
Kakegawa, Tomohito, T. Ogawa, Yumiko Hayashi, et al.. (1988). Effect of various polyamine analogs on in vitro polypeptide synthesis. Archives of Biochemistry and Biophysics. 261(2). 250–256. 10 indexed citations
20.
Matsuzaki, Shigeru, Koei Hamana, Masaru Niitsu, Keijiro Samejima, & Satoshi Yamashita. (1987). Formation of aminopropylhomospermidine from homospermidine in yeasts and thermophilic bacilli. FEMS Microbiology Letters. 48(1-2). 1–4. 5 indexed citations

Rankless uses publication and citation data sourced from OpenAlex, an open and comprehensive bibliographic database. While OpenAlex provides broad and valuable coverage of the global research landscape, it—like all bibliographic datasets—has inherent limitations. These include incomplete records, variations in author disambiguation, differences in journal indexing, and delays in data updates. As a result, some metrics and network relationships displayed in Rankless may not fully capture the entirety of a scholar's output or impact.

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