Search

A simple method for determining short-chain fatty acids (SCFAs) in rat and human feces was developed using high-performance liquid chromatography with electrochemical detection (HPLC-ECD). A two-channel HPLC-ECD system was fabricated using an ion exclusion column and an electrochemical detector with a glassy carbon working electrode. Aqueous solutions of 0.1 mM HClO(4) and of ethanol containing 2-methyl-1,4-naphthoquinone served as a mobile phase and a quinone solution, respectively. Peak areas for lactic, acetic, propionic, butyric, isovaleric, and valeric acids at a detection potential of -0.9 V vs. an Ag/AgCl electrode showed a linear relationship with the acid amount in the range 0.1 to 40 nmol. Standard acids at 4 nmol were determined ten times with relative standard deviations (RSD) of less than 2.0%. The analytical results of healthy human feces were measured within 35 min. RSD (n = 5) in all SCFAs were less than 2.7%, and recoveries of SCFAs were more than 92%. The present method was characterized by reproducibility with the simple and rapid procedure without derivatization of analytes, and it has the potential for clinical and biomedical applications.

We investigated peripheral-blood mononuclear cell (PBMC) response to immunosuppressive drugs and its influence on glucocorticoid therapy in ulcerative colitis (UC). IC50s of immunosuppressive drugs on in vitro blastogenesis of PBMCs stimulated with concanavalin A were estimated in 76 UC and 146 healthy subjects. Individual differences in IC50s for prednisolone, methylprednisolone, cyclosporine, and tacrolimus on blastogenesis of PBMCs from UC patients were spread from 11.0 to 1000, 0.6 to 1000, 0.01 to 1000, and 0.001 to 4.6 ng/ml, respectively. Normal upper thresholds for IC50s of these drugs were estimated from the mean + 2 S.D. of the IC50s of healthy PBMCs, and the patients exhibiting IC50s over these levels were arbitrarily considered as resistant. The incidences of resistance to glucocorticoids and cyclosporine in UC were significantly higher than those in healthy subjects (p < 0.0005). In 14 UC patients, there was a significant correlation between amounts of prednisolone (p < 0.05) or period of prednisolone administration (p < 0.05) for UC treatment and prednisolone IC50. The results showed that large individual deviations in PBMC response to the drugs were observed in UC, and UC patients exhibiting low PBMC sensitivity to prednisolone required a high prednisolone amount as well as long period of prednisolone administration for treatment. Thus, the drug sensitivity tests could be informative to single out refractory patients to the immunosuppressive therapy.

症例は63歳,男性.大動脈弁閉鎖不全兼狭窄症にて弁置換術施行後,便潜血反応陽性を指摘され,大腸内視鏡を施行した.以来6年間の経過観察中に5個の早期癌,39個の腺腫が認められた.早期癌はすべてIIa型で,癌および腺腫の22.7%(10/44)は表面型腫瘍であり,これらの多くは右側大腸に分布していた.本症例は母親が73歳,妹は58歳で大腸癌で死亡しておりHNPCCの診断基準に合致し,さらにLynchらのflat adenoma syndromeの可能性も考えられた.1992年に肝弯曲部のII a型早期癌に対し,右半結腸切除術が施行された.深達度sm1の腺腫を伴う高分化型腺癌で,同病変の遺伝子学的検索ではK-ras codon 12の点突然変異は陰性,p53変異陽性,microsatellite instability陰性であった.家族内に大腸癌集積を示す表面型腫瘍多発症例においてもp53の異常が関与する可能性が考えられたが,マイクロサテライト領域の遺伝子不安定性についてはさらに症例数を増やしての検討が必要と考えられた.

腸内細菌が産生する糞便中発癌関連酵素について, DMH誘発ラット実験大腸癌に対する食餌の影響を検討した.セルロース投与群では全経過を通して各種酵素活性は減少し, とくにNitroreductaseおよびAzoreductase活性は中期, 後期いずれも有意に減少した (p

The relationship between Streptococcus (St.) bovis endocarditis and colon cancer is well known. In St. bovis, the biotype I strain (formerly, St. gallolyticus) produces tannase that degrades tannins. The aim of this study was to investigate the association of tannase-producing bacteria with colon cancer, and to identify the major tannase-producing bacteria and the gene involved.Tannase-producing bacteria were isolated in tannic acid-treated selective agar medium from feces and rectal swabs of 357 patients who underwent colon endoscopy from 1999 to 2004.Tannase-producing bacteria were isolated more frequently from the colon cancer group (24.3%) than from the adenoma or normal groups (14.4%; P0.05). S. gallolyticus, Staphylococcus (S.) lugdunensis, Lactobacillus (L.) plantarum, and L. pentosus were all identified as tannase-producing bacteria. Of these, S. lugdunensis was significantly isolated from the advanced-stage cancer group (22.2%; P0.001) more than from the early-stage cancer (8.6%) or adenoma (4.9%) groups. The gene (tanA) for tannase in S. lugdunensis was cloned and sequenced. The tanA gene was associated with all S. lugdunensis but not with other bacteria by Southern blotting and polymerase chain reaction.Tannase-producing S. lugdunensis is associated with advanced-stage colon cancer, and the tanA gene is a useful marker for the detection of S. lugdunensis.

各種便潜血反応の経時的変化を見るために,溶血液を糞便中に混和し,反応の推移を検討した。検体をそのまま室温で保存した場合,化学法であるスライドA,B法は2日目より免疫法であるラテックス凝集法でも3日目より反応が弱くなった。検体を4℃で保存した場合,いずれの方法でも反応に変化はなかった。スライドに検体を塗布して室温保存した場合,スライドA法は変化がなく,スライドB法では4日目からやや反応は弱くなったが陽性が持続した。ラテックス凝集法で,検体を緩衝液中に混和し室温で保存した場合,4日目から反応が弱くなった。さらに,ラテックス凝集法で糞便中ヘモグロビンを定量的に測定した結果,検体の室温保存で3日目に45%,8日目で40%まで低下したが,検体を緩衝液中で保存した場合は,室温保存でも3日目で100%,8日目でも90%と変化は少なかった。以上の結果から,数日間の検体保存は冷所で行う必要があるが,スライド塗布か緩衝液中保存であれば,4-5日間の室温保存は可能と考えられた。