HISTOPATHOLOGICAL STUDIES OF THE NERVOUS SYSTEM TUMORS IN RATS INDUCED BY N-NITROSO-METHYL-UREA

Histopathological examinations were made on tumors of the nervous system induced in rats of Donryu strain by weekly intravenous injections with N-nitroso-methyl-urea (NMU) or by a single administration of NMU through the mothers. A total of 176 neural and nonneural neoplasms were produced in this study. It was suggested that the fetal nervous system of Donryu rats was also highly susceptible to the oncogenic effects of NMU. Of these tumors produced, those of the peripheral nervous system amounted to 121, comprising 68.7% of the total number of the neoplasm. Microscopically, most of the nerve tumors showed the histology corresponding to that of human neurinomas. Many tumors, however, disclosed more or less anaplaetic cytological appearance. Fifteen gliomas were produced in the brain and spinal cord. Microscopically, they were classified into mixed glioma, oligondendroglioma and anaplaetic astrocytoma. The commonest brain tumors produced in rats from intravenously treated group were periventricular mixed gliomas, while gliomas in rats from transplacentably treated group showed an isomorphic histology with a close resemblance to that of oligodendroglloma.     

AN INHIBITORY EFFECT OF SALIVARY GLAND EXTIRPATION ON THE INDUCTION OF MAMMARY TUMORS IN RATS BY N, N'-2,7-FLUORENYLENEBISACETAMIDE

N,N'²-2,7-Fluorenylenebisacetamide (2,7-FAA) was administered orally to 34 female, strain AXC/I rats. Nineteen were pretreated with the extirpation of the salivary glands. The remaining 15 rats received no surgical treatment. Six of these 15 unoperated rats developed mammary carcinomas and seven developed tumors at other sites, whereas none of 19 operated rats had mammary tumors but 8 rats had tumors at other sites. No tumor developed in 4 operated control rats that were on normal diet. The results demonstrate that pretreatment with extirpation of the salivary glands inhibited mammary tumor induction in rats by 2,7-FAA although it did not inhibit induction of other type tumors. The mechanism by which induction of mammary tumors was inhibited is not clear. Ovarian atrophy and hepatic necrosis were observed in both operated and unoperated rats ingesting 2,7-FAA but did not seem to affect carcinogenesis by the carcinogen. Lower body weight was observed in operated rats but it is not considered to be the major cause of a complete inhibition of mammary tumor induction.     

INDUCTION OF INTRACRANIAL TUMORS IN MICE BY HUMAN ADENOVIRUS TYPE 12

C₃Hf/Bi mice inoculated intracranially with human adenovirus type 12 were studied by fluorescent antibody technique and light microscopy.
The cells with fluorescent T antigens were present in the wall of the ventricles and in the epithelium of the choroid plexuses. Tumors were induced in 21 of 45 mice and the predilection sites were the olfactory bulb, the floor of the fourth ventricle and the tapetum which was in contact with the hippocampus.
The relationship between production of the T antigen and tumor development as well as histological features of the tumors was discussed.     

UNDIFFERENTIATED NEUROECTODERMAL TUMORS INDUCED BY HUMAN ADENOVIRUS TYPE 31 IN SYRIAN HAMSTERS

Human adenovirus type 31 was inoculated intraperitoneally into 18 and intracranially into 98 Syrian hamsters within 24 hours of birth. Intra-peritoneal tumors developed multicentrically in 94.4%, 93 days on an average after virus inoculation, while brain tumors developed in 6.1%, 154 days. Intraperitoneal tumors primarily developed in the subserosal tissues and protruded into the peritoneal cavity. Some of five enlarged brain tumors seemed to have extended from the paraventricular regions to the neighboring structures, and one microtumor was located in the subependymal layer. Twenty-six of the 98 hamsters inoculated with virus intracranially unexpectedly developed tumors in the subcutaneous tissue of the skull. Histological, immunohistochemical and electron micrscopic studies revealed that the tumors which developed in the different sites had essentially the same features and were composed of undifferentiated small cells of primitive neuroectodermal nature. The incidence and the characteristics of the tumors were discussed in comparison with those of adenovirus type 12-induced tumors described previously. ACTA PATHOL. JPN. 34: 1313–1326, 1984.     

MORPHOLOGY OF EXPERIMENTAL CHORIONIC TUMORS IN RATS

Four additional chorionic tumors have been obtained by the same method as previously reported1 using 4-NQO and 7,12-DMBA as carcinogens. It was observed that high dosage of DMBA was quite effective in inducing chorionic tumors in rats. Gross and histological appearance of the tumor resembled that of normal placenta in rats. Part of the tumor has been transplanted and is now under observation.     

EXPERIMENTAL STUDIES ON TUMORS OF THE URINARY SYSTEM OF RATS INDUCED BY CHEMICAL CARCINOGENS*

Tumors in rats were induced in the urinary system of rats with basic lead acetate (BLA), N-nitrosodimethylamine (DMN), N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN), N-nitrosodibutylamine (DBN), 3-methylcholanthrene (3-MC) and 4-nitroquinollne 1-oxide (4NQO). These kidney, ureter and urinary bladder tumors were studied by histopatho-logy, histochemistry, autoradiography and electron microscopy. The tumors of the kidney were classified into the following 4 types; renal cell tumors, embryonal cell tumors, transitional cell tumors and hemangioendotheliomas. However, the tumors of all other regions were of one type, transitional cell tumors. Studies by light and electron microscopy and autoradiography and histochemlcal studies on the histogenesis of tumors of the urinary system in rats showed that renal cell tumors may originate from the renal tubular epithelium and from a part of the metanephrogenic tissue, embryonal cell tumors originate from metanephrogenic tissue and hemangioendotheliomas may originate from blood capillaries. Transitional cell tumors of the kidney, renal pelvis, ureter and bladder originate from transitional epithelium.     

INFLUENZA VIRUS INDUCTION OF APOPTOSIS BY INTRINSIC AND EXTRINSIC MECHANISMS

It is now firmly established that apoptosis is an important mechanism of influenza virus-induced cell death both in vivo and in vitro. Data are predominately from experiments with influenza A virus and in vitro experimental systems. Multiple influenza virus factors have been identified that can activate intrinsic or extrinsic apoptotic induction pathways. Currently there is no evidence for influenza virus directly accessing the apoptosis execution factors. The best-studied influenza virus inducers of apoptosis are dsRNA, NS1, NA, and a newly described gene product PB1-F2. PB1-F2 is the only influenza virus factor to date identified to act intrinsically by localization and interaction with the mitochondrial-dependent apoptotic pathway. Both dsRNA and NA have been shown to act via an extrinsic mechanism involving proapoptotic host-defense molecules: PKR by induction of Fas-Fas ligand and NA by activation of TGF- &#103. PKR is capable of controlling several important cell-signaling pathways and therefore may have multiple effects; a predominant one is increased interferon (IFN) production and activity. NS1 has been shown to be both proapoptotic and antiapoptotic. Use of influenza virus NS1 deletion mutants has provided evidence for NS1 interference with apoptosis, IFN induction, and related cell-signaling pathways. Influenza virus also has important exocrine paracrine effects, which are likely mediated via TNF family ligands and oxygen, free radicals capable of inducing apoptosis. Little is known about activation of inhibitors of apoptosis such as inhibitory apoptotic proteins. Whether all these factors always have a role in influenza virus-induced apoptosis is unknown. The kinetics of synthesis of influenza virus factors affecting apoptosis during the replication cycle may be an important aspect of apoptosis induction.     

VASCULARIZATION IN INFANTILE BRAIN TUMORS INDUCED BY HUMAN ADENOVIRUS TYPE 12 IN RATS

Early vascular changes in undifferentiated infantile brain tumors induced by human adenovirus type 12 (Ad 12) in rats were studied using the India ink injection method, scanning electron microscopy (SEM) of vascular corrosion casts, transmission electron microscopy, and the peroxidase anti peroxidase method for glial fibrillary acidic protein detection. The process of vascularization of solid type tumors was divided into five phases : Stage O, no remarkable changes; Stage I, dilatation of vessels; Stage II, formation of vascular network; Stage III, fine branching in the vascular network; and Stage IV, necrosis. SEM of vascular replica in Stage III suggested compression of the vessels by proliferating tumor cells. In the tapetum region, Stage I was recognized in solid type tumors 100 to 230 (m = 180) μm in diameter, while in the olfactory lobes and in the anterior horn of lateral ventricle closely adjacent to the vascular gray matter, Stage I occurred in much larger tumors. In the diffuse type tumors, the dilatation of vessels was first noticed when the tumors were about 1600 μm in diameter. The solid type tumors mainly developed in the poorly vascular subventricular zone, while the diffuse type ones were usually found deep in the vascular gray matter. The results indicate that vascularization is closely related to the local vascularity and the growth pattern of the microtumors, and that of the solid type tumors induced by Ad 12 may be a model of vascular changes in infantile brain tumors which mostly develop and grow rapidly in the subventricular zone which have poor vascular development. ACTA PATHOL. JPN. 34: 1343–1354, 1984.     

伪狂犬病病毒Ea株诱导牛肾细胞凋亡及核基质蛋白的变化

目的研究伪狂犬病病毒(PrV)是否具有诱导组织培养细胞发生细胞凋亡的功能及探讨凋亡细胞核基质蛋白表达的变化。方法利用锥虫蓝(台盼蓝)染色绘制PrV在不同细胞上的增殖曲线;荧光染色观察凋亡细胞核的形态特征;琼脂糖凝胶电泳分析细胞染色体DNA的片段化;高分辨率双向电泳分析细胞凋亡前后核基质蛋白的表达差异。结果膜通透性的DNA特异性结合染料Hoechst 33342染色显示,PrV感染后36h,牛肾(MDBK)细胞核染色质开始固缩、凝聚,细胞核碎裂;DNA提取及琼脂糖凝胶电泳分析表明,细胞染色体DNA发生片段化,形成“DNA梯状”条带(DNA ladder);尽管PrV可以诱导MDBK细胞发生细胞凋亡,但不能诱导IBRS-2,BHK-21及PK-15细胞发生凋亡。MDBK细胞发生凋亡前后核基质蛋白的表达发生改变,存在表达上调、下调、诱导表达及表达遏制等情况。结论PrV诱导细胞发生细胞凋亡是其致细胞死亡的形式之一,间接反映了PrV与宿主细胞间复杂的相互作用。细胞凋亡前后核基质蛋白表达存在的差异说明PrV致MDBK细胞发生凋亡是自身基因产物或诱导或抑制宿主细胞基因表达的结果。     

DNA免疫引起小鼠产生抗丙型肝炎病毒核壳区体液应答的初步研究

采用ｐｃＤＮＡ３与ｐＭＴ两种基因表达裁体，构建包含丙型肝炎病毒（ＨＣＶ）核心区（Ｃ区）或全结构基因区（核心区、包膜区）的质粒。经纯化后直接对Ｂａｌｂ／ｃ小鼠进行骨骼肌或尾部皮内注射，２～６ｗ后采血，用ＥＬＩＳＡ法检测小鼠抗核壳区的体液应答。结果表明：ＤＮＡ免疫可引起小鼠产生抗ＨＣＶ核壳区的体液应答，加强免疫２次后可使特异性抗体平均滴度达到１８００以上。提示ＤＮＡ免疫可作为丙型肝炎病毒感染的潜在防御手段。     

INDUCTION OF METASTASIZING CARCINOMA IN RATS AND THEIR BIOLOGICAL CHARACTERISTICS

Induction of a spontaneously metastasizing carcinoma in rats was attempted.
Four-week-old Sprague-Dawley female rats were thymectomized or/and splenectomized and fed 200 mg (20 mg×10) of 3-methyicholanthrene from 7 weeks of age. In addition to these treatments, the early-appearing tumors were excised in order to select by isoimmunity the late-appearing ones that were less antigenic. The latter were easily transplanted into normal syngeneic female rats with metastasis to remote organs. This metastasizing capacity of the tumor became an inherent character in syngeneic normal rats from generation to generation of transplantation. With one of these tumors (MRMT-1) many cancer cells were histologically detected in circulating blood 3 days after tumor transplantation and arrested in capillary beds of lungs. The spontaneous metastasis to lymph nodes and lungs was macroscopically found within several weeks after tumor transplantation.     

CHARACTER OF THE TUMORS DEVELOPING IN YOUNG HAMSTERS BY THE MIXED CELL TRANSPLANTATION OF PARA-ADENO-VIRUS 12 AND SV40 TUMORS—THE SIMILARITY TO THE TUMORS INDUCED BY PARA-ADENOVIRUS 7

Two mixtures of either allogeneic PARA-adenovirus 12 tumor cells or adenovirus (Adeno) 12 tumor cells and SV40 tumor cells in an equal number of 1 × l0⁷ cells were transplanted subcutaneously at two sites of 10 young hamsters. The former two tumor cells were transplantable in nearly half of the transplants and the latter tumor cells in all of the transplants. By the mixture of PARA-Adeno 12 and SV40 tumor cells, 10 tumors were grown, 7 of which were mixed with Adeno and SV40 types and 3 were solely SV40 type. The other 10 tumors produced by the mixture of Adeno 12 and SV40 tumor cells revealed SV40 type only. Morphologically, Adeno type resembled the tumor induced by Adeno, and SV40 type by SV40. The results sugQest that the existence of SV40 genetic information in Adeno type tumor cells is indispensable to the formation of mixed tumor in allogeneic tumor cell system. The similarity between the tumors developed by the mixed cell transplantation and those induced by PARA-Adeno 7 was discussed both viro-immunologically and morphologically.     

ELECTRON MICROSCOPIC STUDIES OF PLACENTAL AND UTERINE TUMORS INDUCED IN RATS

The ultrastructure of eight 7,12-dlmethylbenz (a) anthracene (DMBA) or 4-nltroquinollne-N-oxide (4-NQO) Induced malignant tumors of placental and uterine origin in the rat were studied. Three of eight tumors had the ultra-structural characteristics of choriocarcinoma. The other five tumors had different fine structures. Two were classified as squamous cell carcinoma, one was as a leiomyosarcoma and the other two were undifferentiated sarcoma.     

LDH ISOZYME ANALYSES OF ETHYLNITROSOUREA-INDUCED CENTRAL NERVOUS SYSTEM TUMORS IN RATS

To provide the significance of LDH isozymes in rat CNS tumors, the changes in lactic dehydrogenase isozyme and calculated ratios of H- to M- subunit were studied by means of polyacrylamide gel enzymoelectrophoresis in tumor extracts from GNS tumors (7 astrocytomas, 4 oligodendrogliomas, 7 mixed gliomas, 6 anaplastic gliomas, 3 glioependymomas, 1 astroblastoma, 11 neurinomas, 8 anaplastic neurinomas and 1 meningioma in Wistar rats which were induced by ethylnitrosourea). The isozyme patterns were compared to those obtained from normal rat CNS tissues. Among the glioma group, oligodendroglioma showed the highest H/M ratio followed by mixed glioma, glioependymoma, astrocytoma, astroblastoma and anaplastic glioma in order of decreasing of H/M ratios. On the other hand, the H/M ratio of neurinoma was significantly higher than that of anaplastic neurinoma. These observation suggested that determination of LDH isozyme patterns could supplement the histological evaluation of brain tumors.     

INDUCTION OF ATROPHIC GASTRITIS IN ICR MICE BY THE ADMINISTRATION OF AN ALLOGENIC ANTIGEN

In an attempt to produce experimental autoimmunity in small animals the experiment was sought to induce atrophic gastritis in IGR/JGL mice. The stomach antigen of ICR mice was extracted and emulsified with an equal volume of Freund's complete adjuvant. This was subcutaneously injected in 5-week-old IGR/JGL mice at 1 week intervals for a total of 1 to 4 administrations. The stomach antibody in the serum gradually increased up to 2⁶ until four weeks after the last injection of the stomach antigen. At the same time pyknosis and a decrease in number of the gastric mucosal cells, which ultimately led to the atrophying of gastric mucosa, developed. Thereafter, concomitant with the decrease in serum antibody against mucous cells, regeneration of mucous cells was especially remarkable, but atrophy of the fundic gland continued. ACTA PATH. JAP. 27: 799-808, 1977.     

蝌蚪提取液诱导HL60细胞分化和凋亡的实验研究

目的 为了寻找新的肿瘤细胞分化诱导剂,探讨蝌蚪醚提取液（Ｔ８７１２）的抗肿瘤作用。方法 将ＨＬ６０细胞培养于Ｔ８７１２和ＲＰＭＩ１６４０按１：２００（ｖ／ｖ）混合的培养基中。结果 Ｔ８７１２能诱导ＨＬ６０细胞向单核／巨噬细胞方向分化,表现为生长抑制,ＮＢＴ还原能力提高,酸性非特异性酯酶（ＡＮＡＥ）活性增加,形态学观察类似单核／巨噬细胞。当Ｔ８７１２与ＲＰＭＩ１６４０培养基按１：１００（ｖ／ｖ）混合     

肿瘤组织中端粒酶活性的研究

目的 了解端粒酶活性高低与肿瘤恶性程度关系。方法 用ＴＲＡＰ－ＥＬＩＳＡ和我们改进的ＴＲＡＰ银染,对肿瘤组织酶活笥进行半定量检测。结果 端粒酶阳性率分别为：胶质瘤星形Ⅱ级４０％,Ⅲ和Ⅳ级１００％,肠癌８４．６２％,食管癌９０％。结论 端粒酶活性与肿瘤恶性程度密切相关,是诊断恶性肿瘤、判断愈后的良好指标。     

白细胞介素—1对大鼠下丘脑室旁核Fos癌蛋白和CRF的诱导作用

将白细胞介素-1(IL)注入大鼠侧脑室,用Fos癌蛋白抗体免疫组化法检测了下丘脑室旁核的激活神经元:大量位于含促肾上腺皮质激素释放因子(CRF)相应区域的室旁核小细胞部神经元呈Fos免疫强阳性。Fos和CRF的免疫双染色显示了许多Fos免疫阳性神经元也呈CRF免疫阳性。此外,在IL-1注射动物中,CRF的免疫阳性显著加强,提示CRF合成增加。