INHIBITION BY 5-IODODEOXYURIDINE OF THE ONCOGENIC EFFECTS OF ADENOVIRUS TYPE 12 IN HAMSTERS

Subcutaneous tumors induced in newborn hamsters by type 12 adenovirus were suppressed when 0.5 mg of 5-iodo-2'-deoxyuridine (IUdR) was given at the same subcutaneous site as the virus. Although one injection of IUdR given immediately after the virus was effective, additional injections on subsequent days reduced further the number of hamsters developing tumors. These effects of lUdR are especially interesting since replication of infectious adenovirus 12 cannot be demonstrated in the hamsters at any time before or after tumor development.     

Adenovirus tumorigenesis: role of the viral genome in determining tumor morphology

Adenovirus type 12 transforms the fibroblastic BHK21 (baby hamster kidney) cell line into rounded or cuboidal cells that give rise in hamsters to undifferentiated small cell sarcomas indistinguishable from those induced in newborn hamsters by inoculation of the virus itself. In contrast. cells from this line transformed by polyoma virus retain their fibroblastic morphology and induce fibrosarcomas in hamsters. This suggests that the morphology of tumors induced by the adenovirus-transformed cells from this line may be determined by the viral genome and that such mechanism may also explain the remarkably uniform microscopic appearance which seems to characterize tumors induced in hamsters by direct inoculation of adenovirus type 12.     

Lymphocytic-choriomeningitis virus in hamster tumor: spread to hamsters and humans

A passage line of a spontaneous hamster fibrosarcoma is contaminated by the virus. of lymphocytic choriomeningitis. Tumors from animals receiving implants when newborn contain high titers of infectious lymphocytic-choriomeningitis virus and complement-fixing antigen, and hamsters receiving implants when weanlings develop high titers of complement-fixing antibody against lymphocytic-choriomeningitis virus. In contrast with the specific reactions of tumorous hamsters to the initiating virus in virus-induced tumors, the development of complement-fixing antibody to lymphocytic-choriomeningitis virus does not depend on the development of tumors. Infant hamsters bearing the tumor have a generalized subclinical infection and seem able to spread virus to other hamsters and to humans.     

Cardiac atria of BIO 14.6 hamsters are deficient in natriuretic factor

The hearts of 220-day-old hamsters of the BIO 14.6 strain are deficient in atrial natriuretic factor; saline extracts of atria produce one-third the natriuretic and diuretic effects of extracts of atria from age-matched normal hamsters. BIO 14.6 hamsters are known to develop congestive heart failure with edema when they are about 200 days old, and the venous congestion and edema are preventable by parabiosis with normal hamsters. The humoral mediator, the deficiency of which causes venous congestion and edema in BIO 14.6 hamsters, may be atrial natriuretic factor.     

Nature of colchicine resistance in golden hamster

The unresponsiveness of the golden hamster to colchicine has been shown to be the result of a resistance of individual cells to the drug. This resistance makes it possible to use hamsters with heterotransplanted tumors for testing the in vivo effects of colchicine on the tumors, with no toxic host reactions.     

Lymphocytic choriomeningitis in a hamster colony causes infection of hospital personnel

A series of febrile illnesses, some severe, among hospital personnel was traced to an outbreak of lymphocytic choriomeningitis in a hospital research colony of Syrian hamsters. By rapid virus isolation and identification techniques, a definitive diagnosis was made 5 days after specimens were received. This outbreak emphasizes the dangers of working with experimental hamsters and tumor cell lines passaged in them.     

Human papovavirus (JC): induction of brain tumors in hamsters

Eighty-three percent of hamsters inoculated at birth with JC virus, a human papovavirus isolated from brain tissue of a case of progressive multifocal leukoencephalopathy, developed malignant gliomas within 6 months. Three brain tumors have been serially transplanted as subcutaneous tumors. JC virus was isolated from five of seven tumors tested. Cells from four tumors were cultivated in vitro. These cells contained an intranuclear antigen with the characteristics of a T antigen, and this antigen was antigenically related to SV40 T antigen. Although virus was not recovered from extracts of serially cultured tumor cells, JC virus was rescued when one tumor cell line was fused with permissive cells.     

Tumor etiology and chromosome pattern

Fibrosarcomas induced in Chinese hamsters and rats by Rous sarcomla virus and 7,12-dimethylbenz(a)anthracene are associated with nonrandom chromosome variation. Although histologically indistinguishable, the tumors induced by the virus or chemical in each host species are characterized by completely different karyotypic patterns.     

Carcinoembryonic antigen present in human colonic neoplasms serially propagated in hamsters

Carcinoembryonic antigen, as measured by radioimmunoassay, is present in two different human colonic tumors that have been serially transplanted and maintained in the cheek pouches of unconditioned, adult golden hamsters. This finding shows that a human tumor-associated antigen can be produced in an animal host.     

Sarcoma-producing cell lines derived from clones transformed in vitro by benzo[a]pyrene

Cells derived from mixed Syrian hamster embryo cultures were treated with pyrene (control) or with benzo[a]pyrene. Transformed clones were obtained only with the carcinogen. Some of the transformed clones were responsible for cell lines that produced tumors when injected into hamsters. These observations provide evidence that chemical-induced oncogenesis can be studied by an in vitro model.     

用两个不同种的土壤农杆菌Agrobacterium tumefaciens和A.rhizogenes对马铃薯细胞进行复合转化的研究

致癌土壤农杆菌Agrobacterium tumefaciens和致根土壤农杆菌A.rhizogenes都具有将其T—DNA整合到植物染色体上,从而对植物细胞进行遗传转化的能力,在植物遗传工程的研究中具有重要意义。本文报道了用这两个不同种的土壤农杆菌,用两种不同的复合侵染方法,对马铃薯块茎切块的细胞进行复合转化的研究结果。一步侵染法是将这两个不同种的细菌悬浮液混合以后,接种于马薯块茎切块上;两步侵染法是先用致根土壤农杆菌侵染马铃薯块茎切块,得到转化的毛根并在无激素的培养基上继代培养无菌毛根一年以后,再将毛根切段用致癌土壤农杆菌接种。对转化细胞特殊标记物质Opine进行电泳分析的结果表明,这两种侵染方法都可以得到复合转化的马铃薯细胞和组织。但是,一步法比两步法具有更多的优越性。这种复合转化现象对于在植物遗传工程的研究中,一次转移多个基因具有重要的意义。     

Immunologic manipulation of metastases due to herpesvirus transformed cells

Herpes simplex virus type 1 (HSV-1), type 2 (HSV-2), and simian virus 40 (SV40) fail to induce immunity in weanling Syrian hamsters to transplant of hamster cells transformed by HSV-2. However, the development of metastatic tumors is markedly enhanced by prior immunization with HSV-1. Immunization with SV40, ultraviolet-irradiated tumor cells, or ultraviolet-irradiated normal hamster embryo cells inhibits the development of metastases. The HSV-hamster system appears a good one for the study of development, prevention, and control of metastases by mammalian cells transformed by a common human virus.     

云芝液体培养过程中胞外酶与胞外多糖的变化

研究了云芝在液体培养过程中胞外酶与胞外多糖等相关指标的动态变化.结果表明,在28℃,150 r/min恒温振荡培养条件下,云芝茵丝体生物量在第12 d达到最大值(6.436 g/L);发酵液的pH值在整个液体培养过程中变化不大;胞外蛋白质浓度于第11 d达到峰值;愈创木酚氧化酶在第12 d达产酶高峰,酶活性为713.2 u;多酚氧化酶分别在第12 d与第18 d出现产酶高峰,其酶活峰值分别是660.1 u和1 001. 0 u;胞外多糖含量的最大值(23.70 mg/L)也出现在第12 d.     

棉铃虫发生与气温因子的关系研究

采用连续10 a的资料研究了棉铃虫(Helicoverpa armigera)发生和气温的关系。结果表明,1、2和5月的平均气温与棉铃虫二代百株卵量呈正相关,6、7月的月平均气温与棉铃虫二代百株卵量呈负相关,7、8月的月平均气温与棉铃虫三代百株卵量的相关系数依次为-0.295 3和0.493 8。三代棉铃虫发生最适宜的月平均气温为25.8~26.7℃;8~9月的月平均气温与棉铃虫四代的相关系数依次为-0.375 9和0.4798;10~12月的月平均气温与次年棉铃虫二代的相关系数依次为0.353 3、-0.151 8和-0.301 0。6月中旬至7月中旬的逐旬平均气温均与棉铃虫二代百株卵量呈负相关;7月上中旬的逐旬平均气温与棉铃虫三代百株卵量呈负相关,7月下旬至8月下旬的逐旬平均气温与棉铃虫三代百株卵量呈正相关。8月和9月上中旬逐旬平均气温与棉铃虫四代依次呈负相关和正相关。8月中旬日最高气温≥30℃的日数与棉铃虫四代百株卵量呈负相关,8月下旬至9月上中旬逐日≥30℃的日数与棉铃虫四代百株卵量呈正相关。10月下旬和11月中下旬逐日最低气温≤0.0℃的日数均与次年棉铃虫二代百株卵量呈正相关,初霜日与次年终霜日之间≤0.0℃的天数与次年棉铃虫二代百株卵量呈正相关。初霜日与次年终霜日的日数与次年棉铃虫二代百株卵量呈负相关。12月上旬至次年2月中旬逐旬日最低气温≤-10.0℃的总日数与棉铃虫二代百株卵量呈负相关,其中2月中旬最低气温≤-10.0℃的日数与棉铃虫二代百株卵量呈负相关。建立了4个气温因子与棉铃虫相关达显著以上水平的回归方程。     

近50年天水市雷暴日数的时空分布特征

利用1964 ～2013年天水市7个测站的逐日雷暴观测资料,对天水雷暴天气的分布情况、年际变化及雷暴地域变化特征等进行了统计分析,结果表明,近50年天水市各站年平均雷暴日数为13.7 ～26.6 d;主汛期（4～9月）雷暴出现日数占全年雷暴总日数的96％,雷暴日数的月变化呈单峰型,其中主峰集中在5～8月,占全年雷暴总日数的81％,冬季几乎不出现;平均雷暴初日、终日分别出现在4月下旬和9月下旬,平均雷暴初终间日数为157 d;天水各站雷暴日数逐年总体呈减少趋势,且与海拔高度呈明显的正相关,自西南向东北方向逐渐增多.     

肝转移瘤的CT诊断（附122例报告）

分析了１２２例经手术与病理证实的肝转移瘤的ＣＴ表现,结果表明：肝转移瘤以小而多发之圆形成类圆形为特征,平扫表现为低密度有１１８例,等密度与高密度各２例,病灶有囊变、坏死３６例;增强扫描无强化７３例,周边有轻度强化４９例,表现有＂牛眼征＂４例。本文并对其诊断及鉴别诊断作了讨论。     

Latent meiotic anomalies related to an ancestral exposure to a mutagenic agent

When urethan is administered to cytologically normal F(2) progeny descended from grandsires exposed to ethyl methanesulfonate, meiotic anomalies in the forms of site-specific X-chromosome deletions and bivalent associations are noted in spermatocytes of male Armenian hamsters examined 6 and 8 days after treatment, respectively. These latent anomalies are initiated and retained in a premutated state for two generations after the ancestral exposure to ethyl methanesulfonate, the additional impetus required to complete the mutational processes being supplied by urethan.     

浙南地区甜菜夜蛾发生规律与测报技术

通过4年研究,明确了甜菜夜蛾在浙南地区大田一年发生5~6代,第6代为不完全代,越冬蛹在设施栽培蔬菜地越冬。4月下旬~5月初陆续羽化,6月上旬~7月上旬为大田第1代,7月上旬~8月上旬为大田第2代,8月上旬~8月底为大田第3代,9月初~9月下旬为大田第4代,10月初~10月下旬为大田第5代,11月上旬~翌年4月下旬为大田第6代,为不完全代。一年中在6月中下旬7、月中下旬、8月中旬、9月中旬有明显发蛾高峰。研究还明确了甜菜夜蛾不同世代不同虫态的发育历期,并利用历期法对甜菜夜蛾发生期进行预测,利用黑光灯发蛾量对甜菜夜蛾的发生程度进行预测预报。     

Melatonin induction of gonadal quiescence in pinealectomized Syrian hamsters

Pinealectomized Syrian hamsters were injected thrice daily with 25 micrograms of melatonin per injection. The injections were administered at 3-hour intervals either during the day or during the night of a photoperiodic cycle of 14 hours of light and 10 hours of darkness. After 6 weeks of treatment with melatonin during the night, both pinealectomized and intact hamsters had reduced testis weight, and pinealectomized hamsters showed decreased levels of serum gonadotropins. Injection of melatonin during the day for 7 weeks either once (75 micrograms) a day or thrice (25 micrograms per injection) daily caused a reduction in testis weight in pinealectomized hamsters. Both pinealectomized and intact females injected with melatonin thrice daily during the day became anovulatory by week 7 of treatment. These results are similar to those observed when hamsters are exposed to a short photoperiod, suggesting that melatonin may be acting as a hormone in mediating the effects of photoperiod on the reproductive system of the Syrian hamster.     

接种不同毒力马立克氏病毒对鸡端粒酶活性和致病性的影响

以MDV京-1株和GA株诱发的MD为肿瘤模型,跟踪测定了鸡生长过程中脾脏组织的端粒酶活性变化。结果表明,端粒酶活性在没有临床症状和可视病变出现之前便可检测到。随着MDV感染日龄的增加逐渐升高,在其相对活力达到最高值后,总体水平略有下降,但依然存在端粒酶活性;而疫苗株CVI988接种后,整个生长过程其端粒酶均呈阴性。发生MD病变的鸡生长迟缓,中枢性免疫器官胸腺和法式囊严重萎缩,并出现体内肿瘤。无论是病变程度,还是死亡个数和时间,京-1株的致病性均高于GA株。