Electron microscopic study of virus particles in yolk sac and placenta and in hematopoietic organs of newborn C3Hf mice.

Examination of yolk sac from a C3Hf and a C3H mouse with the electron microscope revealed the presence of C-type virus particles in the blood islands. Particles were observed budding from the plasma membrane of hemocytoblasts, from erythroblasts, and occasionally from reticulocytes. C-type particles were also found in similar cells in hematopoietic foci in the liver, spleen, and bone marrow of embryos, and they continued to be present in newborn C3Hf mice up to 11 days of age. Particles consistently appeared in the thymus, even in older suckling mice. A comparison is made between the presence of C-type particles in organs of embryonic, newborn, and adult C3Hf mice. C-type particles were not observed in the chorioallantoic placentas from mice that were given injections of mouse leukemia virus (Gross) or from normal noninjected mice; however, intracisternal A-type particles were present in cytotrophoblast cells from these placentas.     

Oncornavirus-like particles in squirrel monkey (Saimiri sciureus) placenta and placenta culture.

Oncornavirus-like particles similar in morphology to type D particles were observed in 1 of 2 squirrel monkey (Saimiri sciureus) placentas. Intracytoplasmic type A particles, immature virus particles, and mature viruses with eccentric or occasionally centric nucleoids were associated with placental syncytiotrophoblasts. A spike layer typical of type B viruses was not detected in viral envelopes. Onvornaviruses, identical to those previously isolated from squirrel monkey tissues and similar to Mason-Pfizer monkey virus, were seen in cultures derived from the virus-positive squirrel monkey placenta cocultivated with a mink lung culture. The major morphologic difference between the in vivo and the in vitro squirrel monkey virus was in the nucleoid position of mature virus particles.     

Human placental aryl hydrocarbon hydroxylase: studies with fluorescence histochemistry.

Tissue sections from human placentas taken at term were studied after time-sequential incubations with benzo[a]pyrene and appropriate cofactors for mixed-function oxidation. Fluorescence microscopy revealed that the enzymic reaction appeared to be most active in the syncytial trophoblast, though the fluorescence of hydroxylated metabolites also could be observed in other placental cell types. A comparison of sections from placentas with very low versus very high aryl hydrocarbon hydroxylase activities provided evidence that induction of the human placental enzyme system with pol7cyclic aromatic hydrocarbons also appeared to occur primarily in the syncytium. When considered in conjunction with previous studies on human placental aryl hydrocarbon hydroxylase, the results tended to indicate that fetal elements of the human placenta contain the necessary electron-transport components for catalysis of mixed-function oxidations of chemical carcinogens and other foreign compounds and that this hydroxtlase system is readily inducible in the same fetal cells by components present in cigarette smoke.     

Determinants of polycyclic aromatic hydrocarbon-DNA adducts in human placenta.

To determine the relative contributions of tobacco smoking and P-450 metabolism (cytochrome P-450IAI) in the formation of benzo(a)pyrenediol-epoxide and other polycyclic aromatic hydrocarbon-DNA adducts in vivo, 16 human placentas were assayed for aryl hydrocarbon hydroxylase activity and (+/-)r-7,t-8-dihydroxy-c-9,10-epoxy-7,8,9,10-tetrahydrobenzo(a)pyrene-DN A adduct levels. Immunoaffinity chromatography columns, conjugated with monoclonal antibodies raised against benzo(a)-pyrene-diol-epoxide-deoxyguanosine, were used to concentrate polycyclic aromatic hydrocarbon-DNA adducted nucleotides, and synchronous fluorescence spectroscopy was used specifically to detect r-7,t-8,t-9,c-10-tetrahydroxy-7,8,9,10-tetrahydrobenzo(a)pyrene (BP-tetrol) extracted from acid hydrolysates of immunoconcentrated materials. Data were analyzed for associations with maternal dietary and smoking habits, umbilical cord blood cotinine levels, and placental aryl hydrocarbon hydroxylase levels. Complex mixtures of fluorescent materials were present in organic solvent extracts of acid hydrolysates of immunoconcentrated nucleotide-adducts from all placentas with patterns of fluorescence that may be associated with tobacco smoking determined by generation of spectral fluorescence excitation-emission matrices. BP-tetrols were detected in extracts from 8 placentas: 5 of 7 from smokers and 3 of 9 from nonsmokers. Placental aryl hydrocarbon hydroxylase activity was significantly higher in placentas from which BP-tetrols were extracted [3.9 +/- 2.4 [corrected] (mean +/- SE) pmol 3-hydroxybenzo(a)pyrene mg protein-1 min-1], than among placentas from which BP-tetrols were not extracted (0.4 +/- 0.2 [corrected] pmol 3-hydroxybenzo(a)pyrene mg protein-1 min-1) (P = 0.03, Student's t test). This association was independent of maternal smoking or umbilical cord blood cotinine levels. These results indicate that while maternal tobacco smoking is associated with the accumulation of putative, but as yet unidentified, polycyclic aromatic hydrocarbon-DNA adducts in placenta, metabolic capacity appears to be the principal determinant for the (+/-)r-7,t-8-dihydroxy-c-9,10 epoxy-7,8,9,10-tetrahydrobenzo(a)pyrene-DNA adduct levels detected.     

The widely-distributed tumour protein, oncomodulin, is a normal constituent of human and rodent placentas

Oncomodulin, first found in tumours, turns out to be a highly conserved oncodevelopmental protein in human and rodent placentas. The human and rat placental oncomodulins were visualised immunohistochemically. The placental oncomodulins are identical to each other, and to tumour oncomodulin with respect to amino acid composition, chromatographic elution and the pattern of the peptides released by trypsin action.     

Polycyclic aromatic hydrocarbon-DNA adducts in spontaneously aborted fetal tissue

Fetal tissue and placentas from 15 human spontaneous abortions were evaluated for DNA adducts of polycyclic aromatic hydrocarbons (PAHs), using a competitive enzyme-linked immunosorbent assay (ELISA) with fluorescent end-point detection. PAH-derived adducts were found in 43% of placentas, 27% of fetal liver samples and 42% of fetal lung specimens, thus confirming that the human fetus is a target for DNA damage. As there was only 60% concordance between placenta and fetal lung or liver on the presence or absence of detectable PAH adducts, the placenta was not a good surrogate for adduct formation in other fetal organs. PAH-derived adducts in fetal liver and lung presumably form as a result of transplacental exposure to environmental stimuli. Since none of the positive fetal samples were from women who reported smoking during pregnancy, cigarette smoke is, in this case, an unlikely candidate and the adducts detected must be due to some other common source(s) of hydrocarbon exposure. The high frequency of positive samples in our small series casts some doubt on whether fetal PAH-DNA adducts identify a population at increased risk for transplacental carcinogenesis.     

Histological, histochemical and electron microscopic changes of the placenta induced by maternal exposure to hyperthermia in the rat.

Both clinical and experimental investigations have shown that maternal hyperthermia during critical stages of embryo development can induce malformations in the offspring. Studies of the effect of heat stress on the placental functions are limited to the ewes, but that on microscopic structure is unknown. In the present study, rats were exposed to 41 or 42 degrees C for 1 h on gestation day (GD) 9. The controls were sham treated. Fetuses and placentas were collected on GD 20. Intrauterine growth retardation (IUGR) and several craniofacial malformations were observed in the fetuses of the heat-treated group. The placentas of the 42 degrees C group were significantly lighter in weight than those of the control. Light microscopy (LM) revealed thickening, hyalinization and occasional lymphocytic infiltration of the decidua basalis. Giant cells were prominent and glycogen cells had degenerated, leaving behind large cysts in the basal (spongy) zone. Best's carmine stain with or without diastase indicated the reduction in number and degeneration of glycogen cells and cyst formation. The labyrinthine zone was relatively thin in comparison to that of the controls. Perivascular fibrosis and paucity of vascularization were other features of the placentas of the hyperthermia group. Electron microscopy (EM) revealed lipid droplet accumulation in the trophoblast, the presence of myelin bodies and an increased production of collagen in the basal zone. Perivascular fibrosis appeared to have contributed to placental barrier thickening. EM also revealed accumulation of glycogen and lipid droplets in the trophoblasts and fibrin secretion into the extracellular space of the labyrinthine zone. These data suggest that placental pathology possibly contributes to fetal growth retardation in maternally heat-stressed rat fetuses.     

Progesterone receptor gene restriction fragment length polymorphisms in human breast tumors.

We examined the progesterone receptor (PgR) gene in tissue from both primary human breast tumors and normal placentas, detecting restriction fragment length polymorphisms (RFLPs) with the restriction endonucleases Pst I/Sst I and HindIII. There was a general agreement of the Pst I and Sst I polymorphisms in any individual tumor, suggesting that they define two alleles in the human PgR locus, one being characterized by a deletion of about 300 base pairs with respect to the other. Both primary human breast tumor specimens (n = 36) and human term placentas (n = 48) displayed similar allele frequencies and typical mendelian distribution of these Pst I/Sst I alleles. The previously reported HindIII PgR RFLP was also investigated in 132 breast tumors. The HindIII PgR gene RFLP did not display typical mendelian distribution in the breast tumors; the factors affecting the HindIII allele frequencies are presently unknown. Neither the HindIII RFLP nor the deletion defined by Pst I and Sst I correlated with PgR expression as determined by a ligand-binding assay, suggesting that neither is related to the heterogeneity of PgR expression seen in breast tumors.     

电子垃圾污染区新生儿胎盘镉含量及金属硫蛋白表达水平

目的：检测贵屿电子垃圾污染区新生儿胎盘镉含量及胎盘金属硫蛋白（metallothionein,MT）表达量,评估贵屿地区新生儿镉暴露情况及对新生儿的可能影响。方法：选取贵屿当地医院妇产科2006年7~9月出生的足月健康新生儿胎盘100例为实验组,纳入研究的产妇为贵屿镇当地居民,妊娠期间在贵屿居住。取汕头市潮南民生医院妇产科2006年5~6月出生的足月健康新生儿胎盘52例为对照组,产妇来自贵屿周边乡镇。石墨炉原子吸收法检测胎盘镉含量。链霉菌素_生物素（S_P）免疫组化技术检测胎盘组织MT的表达水平。问卷调查收集可能影响镉负荷的产妇年龄、家庭、环境、健康、饮食等因素。结果：实验组新生儿胎盘镉水平的平均值为（0.17±0.48）μg/g,明显高于对照组（0.10±0.11）μg/g,差异具有统计学意义（P〈0.01）。相关分析表明产妇在贵屿居住时间、产妇妊娠期间在贵屿居住时间、产妇怀孕期间在公路附近活动时间是影响胎盘镉水平的主要因素。S_P免疫组织化学检测显示胎盘组织中蜕膜细胞、合体滋养层细胞、绒毛间质细胞均有MT的表达。实验组胎盘组织MT阳性表达率（67.00%）高于对照组（32.69%）（P〈0.01）。新生儿胎盘MT表达量与胎盘镉水平呈显著正相关（r=0.761,P〈0.05）。结论：贵屿部分新生儿处于高镉负荷状态,贵屿当地环境和从事电子垃圾作业是影响当地新生儿高镉负荷的危险因素。贵屿地区新生儿胎盘可能通过增加MT的表达拮抗镉的毒性。     

E-cadherin及nm23-H1在滋养细胞疾病中的表达及意义

目的:探讨E-cadherin及nm23-H1基因在妊娠滋养细胞疾病发生发展中的作用.方法:采用免疫组化法检测24例葡萄胎(随访2年以上未发生恶变)、15例侵蚀性葡萄胎、15例绒毛膜上皮癌、18例正常绒毛组织的石蜡包埋标本E-cadherin和nm23-H1基因的表达状况.结果:E-cadherin的表达在正常早孕绒毛高于侵蚀性葡萄胎和绒毛膜癌(P＜0.01),葡萄胎高于侵蚀性葡萄胎和绒毛膜癌(P＜0.05).nm23-H1的表达正常早孕绒毛明显高于恶性滋养细胞疾病(P＜0.01),葡萄胎高于侵蚀性葡萄胎(P＜0.01)和绒毛膜癌(P＜0.05).在葡萄胎和恶性滋养细胞疾病中E-cadherin和nm23-H1基因的表达均为正相关.结论:滋养细胞疾病E-cadherin和nm23-H1表达与其侵袭性相关,二者可能成为葡萄胎预后的标志物.在侵袭转移过程中细胞滋养细胞较合体滋养细胞更为重要.     

Expression of cyclin E in placentas with hydropic change and gestational trophoblastic diseases: implications for the malignant transformation of trophoblasts

BACKGROUND: Although much is known about the morphologic, cytogenetic, and clinical characters of gestational trophoblastic diseases, little information has appeared concerning the parameters related to their persistence or neoplastic transformation. Cell cycle alterations in tumor tissue were examined in this study in light of obvious changes in the clinical behavior of malignant cells. There is an increasing body of evidence suggesting that the abnormal expression of cyclins is considered one of the most important events in malignant transformation of various human cancers. Among these cell cycle regulators, the role of cyclin E in the neoplastic transformation of trophoblast populations has been poorly defined. METHODS: Using formalin fixed, paraffin embedded trophoblastic tissues, the authors investigated the expression of cyclin E by immunohistochemistry in placentas with hydropic change and gestational trophoblastic diseases. The specimens examined included tissue from 29 patients with complete hydatidiform mole, 18 patients with partial hydatidiform mole, and 6 patients with choriocarcinoma after term pregnancy or abortion. The authors also studied four cases of hydropic abortion. RESULTS: The cyclin E indexes (CEI) were as follows: 25.7% +/- 6.2% for hydropic change, 35.3% +/- 12.7% for triploid partial moles, 42.2% +/- 13.1% for diploid/tetraploid complete moles, and 63.6% +/- 9.5% for choriocarcinomas. There was a significant difference in CEI between placentas with hydropic change and partial mole (P = 0.04) and placentas with hydropic change and complete mole (P = 0.003). Choriocarcinomas had significantly higher cyclin E expression compared with placentas, partial moles, and complete moles, respectively. A significant correlation between the expression of cyclin E and S-phase fraction was observed in gestational trophoblastic diseases (rank correlation coefficient = 0.45, P < 0. 05). The relation between cyclin E expression and proliferation was abrogated in placentas with hydropic change, suggesting that cyclin E up-regulation represents a genuine aberration. CONCLUSIONS: The results of this study were consistent with the concept that cyclin E overaccumulation may play an important role in the uncontrolled proliferation and neoplastic transformation of trophoblasts.     

Tumors arising from injection of cultured murine placental cells into normal animals: direct evidence for placental origin of tumors of two histologic types

Long-term culture of placentas obtained from the mating of a congenic C3H male mouse carrying a unique electrophoretic variant of the X-chromosome-linked enzyme phosphoglycerate kinase (PGK-1) and a normal C3H female mouse has resulted in cell lines that have apparently undergone spontaneous malignant transformation in vitro. When injected into normal syngeneic animals, these cell lines have given rise to invasive carcinomas of two distinct histologic types, an adenocarcinoma and a poorly differentiated carcinoma. Both were demonstrated to be of placental origin by the continued presence of the allozyme coded on the paternal X-chromosome. Compared to murine tumors of other etiologies, these cell lines were characterized by a high intracellular alkaline phosphatase concentration.     

Population distribution of placental benzo(a)pyrene metabolism in smokers

Human placental microsomes isolated from term placentas derived from nonsmoking women and women smoking 1 to 40 cigarettes a day were analyzed for the metabolism of benzo(a)pyrene measured as various metabolites by HPLC and/or as aryl hydrocarbon hydroxylase (AHH)6 activity. In accordance with other reports, AHH activity was several times higher in smokers than in nonsmokers. Regression analysis on 13 different placental tissues from women smoking from 1 to 40 cigarettes demonstrated a high correlation (r = 0.8 to 0.9) between AHH activity (or the formation of benzo(a)pyrene phenols resolved by HPLC) versus the formation of the procarcinogenic benzo(a)pyrene-7,8-diol. Subsequent studies on placentas derived from 67 women who smoked 10 to 40 cigarettes per day demonstrated a definite dose-response relationship between AHH activity and the number of cigarettes smoked/day. The dose-response curve was sigmoidal in shape; however, when the data were plotted on a semi-log scale the curve assumed a linear shape, reaching saturation of AHH induction beyond 20 to 25 cigarettes/day. While mean AHH activity was dependent upon the number of cigarettes smoked/day, considerable interindividual variability in AHH (ranging more than 1,000-fold in some cases) was observed among individuals with comparable smoking histories, i.e. smoking the same number of cigarettes. Population distribution suggested clustering of the population in the low-AHH-activity region while cord-blood thiocyanate analysis and twin studies suggested that genetic factors contributed to a major portion of the inter-individual variability in AHH activity observed among smokers.     

Birth weight of children and cadmium accumulation in placentas of female nickel-cadmium (long-life) battery workers.

In a retrospective epidemiological study on the birth weight of 266 children of 137 female workers in a nickel-cadmium battery factory, 157 children of workers occupationally exposed to cadmium were compared with 109 born to non-occupationally exposed workers. No effect of cadmium exposure on birth weight was detected, but a statistically significant effect on birth weight of smoking during pregnancy was observed. In a prospective study on the same population of female battery workers, 27 placentas were collected and the cadmium distribution and concentration in tissue subsamples determined. Placental cadmium concentrations were positively correlated with maternal blood cadmium. The cadmium concentration in placentas ranged from < 0.002 to 0.095 microgram/g (wet weight), the mean concentration +/- SD was 0.021 +/- 0.022 microgram/g (wet weight). Morphological and ultrastructural studies of placental tissues did not reveal any effect of cadmium. This study did not provide any evidence in support of the hypothesis that the placenta may be the critical organ in exposure to cadmium.     

3-Hydroxyxanthine: transplacental effects and ontogeny of related sulfate metabolism in rats and mice.

The ontogeny of sulfate metabolism related to the metabolic activation of the carcinogenic purine N-oxide 3-hydroxyxanthine (3-OH-X) was studied in noninbred Sprague-Dawley rats. Sulfotransferase activity toward 3-OH-X was detectable in most fetal livers near term at about 25% of adult values and increased slowly after birth. This activity was also present in placentas. Compared to 3-OH-X sulfotransferase, sulfotransferase activity toward p-nitrophenol was lower in fetal livers and was not detected in placentas. Sulfohydrolase activity toward 3'-phosphoadenosine-5'-phosphosulfate was higher in fetal and newborn livers and in placentas than in adult liver. In a parallel transplacential carcinogenicity assay, a low but significant percentage of male rats exposed as fetuses to multiple high doses of 3-OH-X developed single liver carcinomas. After the lowest transplacental dose, the incidence of degenerative kidney disease in old male offspring was significantly higher than that in controls. In an assay with mice, (C57BL/6 X BALB/c)F1 mice exposed transplacentally to 3-OH-X experienced significantly greater perinatal morality and fewer lung adenomas among the surviviors at 20 months of age than did the controls.     

Virus containing lymphocyte cultures from cancer patients

Seven continuous cell cultures were established from 45 lymphoid tissue specimens from 43 cancer patients. All cultures were free-floating and appeared to be primarily lymphoblasts. Electron microscopic examination revealed herpesvirus-like particles in all the established cell lines and in one cell line that was maintained for only 1 month. The particles appeared identical to those observed in Burkitt's lymphoma and other lymphoma and leukemia cultures. In one instance virus particles were observed in the original tissue specimen before cultivation. The virus particles were not infectious for several cell lines known to be susceptible to herpes simplex virus and other members of this group.     

Search for infective mammalian type-C virus-related genes in the DNA of human sarcomas and leukemias.

DNA was extracted from two human sarcoma cell lines, TE-32 and TE-418, and the leukemic cells from five children with acute myelocytic leukemia, three children with acute lymphocytic leukemia and four adults with acute myelocytic leukemia. The DNAs, assayed for infectivity by transfection techniques, induced no measurable virus by methods which would detect known mammalian C-type antigens or RNA-directed DNA polymerase in TE-32, D-17 dog cells and other indicator cells, nor did they recombine with or rescue endogenous human or exogenous murine or baboon type-C virus. Model systems used as controls were human sarcoma cells, TE-32 and HT-1080, and human lymphoma cells TE-543, experimentally infected with KiMuLV, GaLV or baboon type-C virus, all of which released infectious virus and whose DNAs were infectious for TE-32 and D-17 dog cells. Other model systems included two baboon placentas and one embryonic cell strain spontaneously releasing infectious endogenous baboon virus and yielding DNAs infectious for D-17 dog cells but not for TE-32 cells. Four other baboon embryonic tissues and two embryonic cell strains, releasing either low levels of virus or no virus, did not yield infectious DNA.     

Virus particles in the basal plate of rhesus monkey and baboon placenta.

C-type virus particles and particles, approximately 35 nm in diameter, were present in the region of the basal plate from the placenta of a rhesus monkey and two baboons. Both particles appeared to bud from the plasma membrane of the cytotrophoblast: large, pleomorphic cells with cytoplasmic extensions, indented nuclei, well-developed endoplasmic reticulum, and glycogen deposits. Extracellular particles were enmeshed within a fibrous matrix. Particles were also observed in the junctional zone, but not in the decidua. C-type virus particles from the rhesus monkey and baboons differed in ultrastructure from each other and from C-type mouse leukemia virus particles. The 35-nm-type particle was spherical with a dense central core.     

Hepatic clearance of arterially infused ferromagnetic particles

Objective : Arterial embolization hyperthermia (AEH) consists of arterially embolizing tumours with ferromagnetic particles that generate hysteretic heating on exposure to an alternating magnetic field. It was the objective of this study to determine if such particles are cleared from the liver. Method : A lobe of normal liver in three pigs was arterially embolized with 300 mg of &#110 -Fe 2 O 3 particles (150 nm) suspended in lipiodol. The same liver lobe of three other pigs was embolized with 300 mg of ferromagnetic polymer matrix-encapsulated microspheres (32 µm) suspended in 1% tween-water. Samples of liver and blood were obtained before infusion, and at 60 min and 28 days after arterial infusion. At 28 days, samples of lung and other abdominal viscera were also obtained. The tissue samples were chemically analysed for iron content, and submitted to histopathological examination. Results : There was no significant reduction in the hepatic iron concentration in either treatment group 28 days after infusion. Both types of particles illicited an immunogenic response and were extensively phagocytosed in the liver. The particle/lipiodol suspension caused extensive necrosis of liver, while the microsphere/tween-water suspension was well tolerated. Small amounts of both types of ferromagnetic particles embolized in the lungs, but there was no evidence of embolization into other organs. There were no haematological or biochemical changes and all subjects experienced uneventful 28-day survivals. Conclusion : This study has shown that, although arterially infused ferromagnetic particles were extensively phagocytosed, there was no significant hepatic clearance 28 days after infusion. It also determined that the suspension of 150 nm ferromagnetic particles in lipiodol was too vaso-occlusive for use in hepatic tissue. However, the suspension of 32 µm microspheres containing ferromagnetic particles in tween-water was safe and well tolerated.