Hiroo Katayama

Correlative histochemical studies on preneoplastic and neoplastic lesions in the kidney of rats treated with nitrosamines.

SummaryRenal tubular lesions induced in male rats by two different carcinogens, N-nitrosomorpholine (NNM) and N-ethyl-N-hydroxyethylnitrosamine (EHEN), using a limited exposure “stop” protocol were investigated histochemically to demonstrate phenotypic cellular changes. The parameters measured included basophilia, glycogen content and the activity of the enzymes glucose-6-phosphatase (G6PASE), glycogen synthetase (SYN), glycogen phosphorylase (PHO), glucose-6-phosphate dehydrogenase (G6PDH), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), succinate dehydrogenase (SDH), alkaline phosphatase (ALP), acid phosphatase (ACP) and γ-glutamyl transpeptidase (γ-GT). The lesions observed were predominantly of either basophilic or oncocytic types. In each case, tubular lesions (altered tubules) appeared to give rise to epithelial tumors (epitheliomas) with the same cellular phenotype. Basophilic tubules and epitheliomas proved to be strongly positive for GAPDH and G6PDH while demonstrating a reduction or loss of G6PASE, ALP, ACP, γ-GT, and SDH compared with controls and the surrounding proximal or distal tubules. In addition, large basophilic epitheliomas demonstrated an increase in both SYN and PHO activities. In contrast, most oncocytic tubules and oncocytomas characterized by bundant densely granular cytoplasm showed a reduction in the activity of G6PDH, but were intensely positive for SDH. However, a few oncocytic lesions demonstrated a decrease in both SDH and G6PDH activity. Rarely, decreased SDH and elevated G6PDH activities were observed in altered tubules resembling oncocytic tubules. It remains to be clarified whether these tubules represent a variation of the oncocytic lesions or, perhaps, another type of tubular lesion. The results indicate that basophilic and oncocytic epithelial tumors differ in their cytochemical pattern and histogenesis. In line with earlier suggestions, the basophilic tumors apparently originate from the proximal renal tubules, while the oncocytomas develop from the distal parts of the nephron. The basophilic tumors are characterized by an increased pentose phosphate pathway and glycolysis, with a corresponding reduction in mitochondrial respiration. However, the majority of the oncocytomas show an increased activity of the mitochondrial enzyme SDH, and a marked decrease in the activity of the key enzyme of the pentose phosphate pathway.

Evaluation of glycogen level in human lung carcinoma tissues by an infrared spectroscopic method

Glycogen levels in the tissue samples obtained from carcinomas and normal sections of human lungs (26 patients) were studied by measuring the infrared band intensity at 1045 cm(-1) due to glycogen. As an internal standard peak, the band at 1545 cm(-1) (amide II) was chosen, and the ratios of these band areas (A1045/A1545) were compared with histological classification and differentiation of tumors. The glycogen level in the carcinoma tissues was significantly higher than that in the normal tissues (P < 0.01, n = 26). Further, the ratio of amounts of glycogen in the carcinomas and in the normal tissues for adenocarcinoma was higher than that for squamous cell carcinoma (P < 0.01). The increased degree of differentiation of the squamous cell carcinomas appeared to be correlated with an increase in the glycogen level. These results suggest that comparison of glycogen levels in the tumor and normal section of human lung may be used as a differentiating parameter for abnormality and histological classification of tumors. The present Fourier transform-infrared spectroscopy (FT-IR) method may become of wide application for studying various tissue samples.

Detection of the cytogenetic effect of inhaled aerosols by the micronucleus test

The induction of micronuclei in mice exposed to aerosols of the following 6 genotoxic chemicals by inhalation was examined: cyclophosphamide (CP), methyl methanesulfonate (MMS), mitomycin C (MMC), dimethylnitrosamine (DMN), ethylcarbamate and colchicine. Exposure of mice to CP aerosols at a theoretical concentration of 2426 mg/m3 for 29, 81 and 139 min induced 0.6, 1.0 and 2.3% micronucleated polychromatic erythrocytes (MNPCEs) in bone marrow 24 h after the termination of exposure. The other chemicals except for DMN showed a similar exposure-response relationship following in vivo exposures to their aerosols. The results obtained in this study suggest that the cytogenetic effect of inhaled aerosols can be detected by the micronucleus test, and the method described in the present report is useful as a rapid in vivo test for atmospheric aerosols.

Applications of Fourier transform infrared spectroscopy, Fourier transform infrared microscopy and near-infrared spectroscopy to cancer research

Glycogen levels in human lung and colorectal cancerous tissues were measured by the Fourier transform (FT-IR) spectroscopic method. Reliability of this method was confirmed by chemical analyses of the same tissues used for the FT-IR spectroscopic measurements, suggesting that this spectroscopic method has a high specificity and sensitivity in discriminating human cancerous tissues from noncancerous tissues. The glycogen levels in the tissues were compared with the clinical, histological and histopathological factors of the cancer, demonstrating that glycogen is a critical factor in understanding the biological nature of neoplastic diseases. Furthermore, direct measurement of a very small amount of tissue by a FT-IR microscope suggested that it could be used as a diagnostic instrument for various tissue samples obtained via a fine needle biopsy procedure. The progressive alterations in rat mammary gland tumors were investigated by a near-infrared (NIR) spectrometer with a fiber optic probe. A lipid band due to the first overtone of n-alkane was used to quantitatively evaluate malignant changes in the tumors. NIR spectroscopy may offer the potential for non‒invasive, in vivo diagnosis of human cancers.

Determination of Glycogen Levels in Human Lung Cancer and Normal Tissues by Fourier Transform Infrared Spectrometry

Glycogen levels in the carcinoma and normal tissues of human lungs were studied by the FT-IR method using the integrated area ratios of glycogen to protein (A1045/A1545). Further amounts of glycogen and protein contained in the same tissues were measured by an anthrone method and by using a dotMETRIC™ kit, respectively. Ratios of glycogen to protein obtained here were compared with the FT-IR spectroscopic data in relation to abnormality and histological classification of the tumors indicating a good correlation between them. The present results show that the FT-IR method is very reliable and that may be of wide application for studying glycogen levels in various tissues as well as diagnosis purpose.

クロム化合物の呼吸器への影響(第3報) : 酸化クロムの吸入暴露実験

殺,解 剖 し呼 吸器 系 を中 心 に病理 組 織学 的 検 索 を 行 っ た. 3)肺 内 ク ロム濃 度測 定: 12か 月 お よび24か 月解剖 例 の ホル マ リン固定 肺 の うち,病 理 組織 標 本 と した 以外 の部 分 につ い て,硫 酸-硝 酸-過 塩 素酸 に よる1湿 式 分 解 後,フ レー ム レス原子 吸光 法 に よ りクロム濃 度 の測定 を 行 った. 結 果 1)途 中経過:吸 入暴露中は各ラッ トともに変化はな い.ま た,吸 入暴露後数 日間は酸化 クロムによる糞の緑 色着色をみたが,出 血,下 痢 などは観察 されなかった. 途中死亡の8例 はいずれ も実験開始から1年 以降に続 発 し,急 性お よび慢性の気管,気 管支肺炎を発症 してい た. 2) 12か月解剖例:肺 の肉眼的所見 では,各 例とも酸 化 クロム粉 じんの集合に よる肺胸膜面の緑色小斑点お よ び肺門 リンパ腺の緑色着色を認めたほか,と くに異常は 観察 されなか った.組 織学的には,粉 じん沈着は主とし て気管支お よび血管周囲の リンパ組織中にあ り,胸 膜面 Table 1. Inhalation chromic oxide (Cr2O3) dust.*