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E C Miller

Publications and source records attributed to E C Miller.

At least 55 records · Page 3Linked to original sources
PubMed1984

[Changes in the immunoglobulins IgG, IgA and IgM in pregnancy and the puerperium].

Immunoglobulin IgG, IgA and IgM levels in maternal serum of 16 healthy pregnant women are analysed between 7th and 37th week (n = 95) and additionally at second day after delivery. Serum immunoglobulin concentrations of 54 healthy non-pregnant young women are the base for laboratory-specific normal levels. IgA and IgG raise at the beginning of pregnancy and decrease after 17th week; IgA levels after 20th week of pregnancy are not different from concentrations of non-pregnant women. Compared to this, IgG levels fall below the prepregnancy niveau significantly. This continuous decrease lasts anabatedly till the second day following delivery. On the contrary, IgM decrease immediately with starting pregnancy, whereas the following decrease is unessential. After delivery levels rise rapidly. A shortlasting decrease of the concentration of all three immunoglobulins IgG, IgA and IgM with consecutive increase between the 11th and 14th gestational week is a special characteristic sign.

Adult↗
PubMed1984

Characterization of the biliary and urinary glutathione and N-acetylcysteine metabolites of the hepatic carcinogen 1'-hydroxysafrole and its 1'-oxo metabolite in rats and mice.

The hepatocarcinogen safrole is metabolized both to 1'-hydroxysafrole, a proximate hepatocarcinogen, and to 1'-oxosafrole, which is electrophilic but has little or no carcinogenic activity in rats and mice. As a part of a study on the metabolic interrelationships of these metabolites, their biliary and urinary conjugates were investigated. Administration of a single i.p. dose of [2',3'-3H]-1'-oxosafrole to male Sprague-Dawley rats or female CD-1 mice with cannulated bile ducts resulted in the excretion of 2 major biliary metabolites. These metabolites were isolated by high-performance liquid chromatography and characterized by 1H-nuclear magnetic resonance spectroscopy as 3'-(glutathion-S-yl)-1'-oxo-2',3'-dihydrosafrole and 3'-(N-acetylcystein-S-yl)-1'-oxo-2',3'-dihydrosafrole. The latter conjugate was also found in the urine. These conjugates were synthesized by non-enzymatic reaction of 1'-oxosafrole with glutathione and N-acetylcysteine at pH 8. After a single i.p. dose of [2',3'-3H]-1'-hydroxysafrole, the major biliary and urinary metabolite in rats was the glucuronide of this alcohol. Lower levels of the glutathione and N-acetylcysteine conjugates of 1'-oxosafrole appeared in the bile, and the latter conjugate was also found in the urine. Similar findings were made on the biliary metabolites of 1'-hydroxysafrole in mice. Although the sulfuric acid ester of 1'-hydroxysafrole is the major metabolite leading to the formation of DNA adducts in the liver, it was, at most, of minor importance in the formation of glutathione adducts. Only a very small percentage of a dose of 1'-hydroxysafrole was excreted in the bile of rats or mice as products that cochromatographed with 1'-(glutathion-S-yl)-safrole and 3'-(glutathion-S-yl)-isosafrole; no 3'-(N-acetylcystein-S-yl)-isosafrole was detected. These latter conjugates were synthesized by nonenzymatic reactions at pH 8.5 of the model electrophilic ester 1'-acetoxysafrole with glutathione or N-acetylcysteine.

Acetylcysteine↗
PubMed1983

Non-arene oxide aromatic ring hydroxylation of 2,2',5,5'-tetrachlorobiphenyl as the major metabolic pathway catalyzed by phenobarbital-induced rat liver microsomes.

Incubation of phenobarbital-induced rat liver microsomes with 2,2',5,5'-tetrachlorobiphenyl (TCB) yielded about 30% of the substrate as 3-hydroxy-TCB, 3,4-dihydroxy-TCB, 3,3'-dihydroxy-TCB (tentative identification), and 3,4-dihydro-3,4-dihydroxy-TCB in relative amounts of about 1:1:0.05:0.05. Under identical conditions, 2,2',5,5'-tetrachlorobiphenyl 3,4-oxide (TCBO) yielded about 45% of the substrate as the above products in an approximate ratio of 0.1:1:0.01:1, as well as 10% as TCB. Omission of NADPH from incubations of TCBO decreased the yields of 3-hydroxy-TCB, both dihydroxy-TCBs, and TCB by 75-100%, increased the yield of 3,4-dihydro-3,4-dihydroxy-TCB 4-fold, and permitted the recovery of small amounts (0.5% yield) of 4-hydroxy-TCB. 3-Hydroxy-TCB and 4-hydroxy-TCB were both extensively metabolized to 3,4-dihydroxy-TCB; 3-hydroxy-TCB was also metabolized to the presumed 3,3'-dihydroxy-TCB. The metabolism of TCBO to 3,4-dihydro-3,4-dihydroxy-TCB was inhibited by 1,1,1-trichloropropene 2,3-oxide. These data indicate that the majority (greater than 90%) of the primary oxidation of TCB occurred via 3-hydroxylation mechanisms not involving TCBO and that only a small fraction occurred via 3,4-epoxidation. The formation of 3-hydroxy-TCB and TCBO from TCB via different pathways was consistent with the observation that TCB-treated rats excreted 6-fold higher levels of 3-hydroxy-TCB in their feces than did TCBO-treated rats.

Animals↗
PubMed1983

The metabolic activation and nucleic acid adducts of naturally-occurring carcinogens: recent results with ethyl carbamate and the spice flavors safrole and estragole.

A small (approximately 30) but varied group of organic and inorganic compounds appear to be carcinogenic in both humans and experimental animals. A much larger number and wider variety of chemical carcinogens, primarily synthetic organic compounds, are known for experimental animals. These agents include a small (approximately 30) and varied group of metabolites of green plants and fungi. Many more of these carcinogens must exist in the living world. As with the synthetic carcinogens, the majority of these naturally occurring carcinogens are procarcinogens that require metabolic conversion into reactive electrophilic and mutagenic ultimate carcinogens. These strong electrophiles combine covalently and non-enzymatically with nucleophilic sites in DNAs, RNAs, proteins, and small molecules in target tissues. One or more of the DNA adducts appear to initiate carcinogenesis in an irreversible manner. The subsequent promotion step leading to gross tumours may be completed by further administration of carcinogen or by treatment with non-carcinogenic promoters. Roles for the RNA and protein adducts in the carcinogenic process have not been excluded. Recent data on the metabolic activation and reactivity in vivo of the naturally occurring carcinogens ethyl carbamate and certain of the alkenylbenzene spice flavours are illustrative of these principles. These agents can initiate the carcinogenic process in male mouse liver with small doses given prior to weaning. Subsequent growth of the liver and male hormonal factors appear to function as promoters leading to gross hepatic tumors after one year. Reactive electrophilic metabolites of ethyl carbamate and of safrole and estragole and their nucleic acid adducts formed during initiation in mouse liver have been characterized.

Adenine↗
PubMed1983

Some historical aspects of N-aryl carcinogens and their metabolic activation.

This limited review of the early studies on the activation of the N-aryl carcinogens was written to provide a background for the current research to be presented at this conference on carcinogenesis by N-aryl compounds. Since the work of the past 10 years is too recent to be judged in a historical sense and because those data are much better known by current investigators, this review is generally limited to data up to 1972.

2-Acetylaminofluorene↗
PubMed1983

Fluorine substitution as a probe for the role of the 6-position of benzo[a]pyrene in carcinogenesis.

The tumorigenic activities of benzo[a]pyrene (BP) and 6-fluorobenzo[a]pyrene (6-F-BP) were compared to determine whether an unsubstituted 6-position is important for the carcinogenic effect of BP. Highly purified samples of 6-F-BP and BP had similar activities for the induction of lung adenomas in Swiss Webster mice treated before weaning. The 6-fluoro derivative, however, had about one-half as much activity as BP for the initiation of skin papillomas in CD-1 mice. Similarly, 6-F-BP (approximately equal to 90% purity) had about one-half the activity of BP for the induction of skin tumors in C57BL/6J mice given repetitive treatments of the hydrocarbons and for the induction of sarcomas in C3H/fCum mice given a single sc injection. 6-F-BP (approximately equal to 90% purity) had activity similar to that of BP for induction of sarcomas at the sc injection site in Fischer 344 rats. These results and related data indicate the need for detailed metabolic studies whenever fluorine substitution is used as a probe to assess the role of the unsubstituted position in the carcinogenicity of the parent compound.

Animals↗
PubMed1983

Strong evidence from studies with brachymorphic mice and pentachlorophenol that 1'-sulfoöxysafrole is the major ultimate electrophilic and carcinogenic metabolite of 1'-hydroxysafrole in mouse liver.

The role of sulfation of 1'-hydroxysafrole in the formation of hepatic macromolecular adducts and in hepatic tumor formation in mice given 1'-hydroxysafrole was investigated by the use of: (a) mice treated with the specific sulfotransferase inhibitor pentachlorophenol; and (b) brachymorphic mice, which are characterized by a deficiency in the hepatic synthesis of 3'-phosphoadenosine 5'-phosphosulfate. Cytosolic sulfotransferase activity for 1'-hydroxysafrole in both mouse and rat liver was significantly inhibited by 10 microM pentachlorophenol, usually by greater than 90%. Prior administration of nontoxic amounts of pentachlorophenol, either in the diet of adult female CD-1 mice or by i.p. injection of 12-day-old male C57BL/6 X C3H F1 (hereafter called B6C3F1) mice, resulted in an 85% decrease in the level of adducts formed from 1'-hydroxysafrole in hepatic DNA and RNA as compared to those of non-pentachlorophenol-treated animals. Likewise, the chronic administration of a nontoxic level of pentachlorophenol in the diet of adult female CD-1 mice strongly inhibited hepatic tumor induction by long-term dietary administration of either safrole or 1'-hydroxysafrole. Initiation of hepatic tumors by a single i.p. injection of 1'-hydroxysafrole to 12-day-old male B6C3F1 mice was strongly inhibited by prior treatment with pentachlorophenol. Under these conditions, the hepatocarcinogenicity of diethylnitrosamine was not inhibited by pentachlorophenol. Supplementation with adenosine triphosphate and sulfate of hepatic cytosols from adult female or 12-day-old brachymorphic progeny of a B6C3 background outbred to B6C3F1 mice (B6C3F2), of either sex, resulted in 5- to 10-fold less binding of 1'-hydroxysafrole to added RNA than when cytosols from phenotypically normal B6C3F2 mice were used. On administration of [3H]-1'-hydroxysafrole to adult female or 12-day-old brachymorphic B6C3F2 mice of either sex, the levels of hepatic DNA and RNA adducts were 7- to 12-fold lower than those obtained in phenotypically normal B6C3F2 mice of the same age and sex. Brachymorphic mice were also much less responsive than their phenotypically normal littermates to the induction of liver tumors by 1'-hydroxysafrole; lower incidences were observed both when the carcinogen was fed chronically to adult females and when it was administered to males only prior to weaning. Thus, all of these data strongly support the conclusion that 1'-sulfoöxysafrole is the major ultimate electrophilic and tumor-initiating metabolite of 1'-hydroxysafrole.

Animals↗
PubMed1983

Structure-activity studies of the carcinogenicities in the mouse and rat of some naturally occurring and synthetic alkenylbenzene derivatives related to safrole and estragole.

Twenty-three naturally occurring and synthetic alkenylbenzene derivatives structurally related to the hepatocarcinogen safrole (1-allyl-3,4-methylenedioxybenzene) were assayed for their hepatocarcinogenicity in mice. Some of these compounds (safrole, estragole, eugenol, anethole, methyleugenol, myristicin, elemicin, and dill and parsley apiols) may be ingested in very small amounts by human as natural components of certain spices, essential oils, or vegetables. Estragole (1-allyl-4-methoxybenzene) and its proximate carcinogenic metabolite 1'-hydroxyestragole, previously shown to induce hepatic tumors when administered to male CD-1 mice only during the preweaning period, also induced hepatic tumors on administration for 12 months in the diet of female CD-1 mice. Eugenol (1-allyl-4-hydroxy-3-methoxybenzene) and anethole (trans-4-methoxy-1-propenylbenzene) were inactive in this assay; they were also inactive when administered i.p. during the preweaning period at total doses of up to 9.45 mumol/mouse to male CD-1 or C57BL/6 x C3H F1 (hereafter called B6C3F1) mice. Methyleugenol (1-ally-3,4-dimethoxybenzene) and its 1'-hydroxy metabolite had activities similar to those of estragole and its 1'-hydroxy metabolite for the induction of hepatic tumors in male B6C3F1 mice treated prior to weaning; 1-allyl-1'-hydroxy-4-methoxynaphthalene was somewhat less active. At the levels tested, myristicin (1-allyl-5-methoxy-3,4-methylenedioxybenzene), elemicin (1-allyl-3,4,5-trimethoxybenzene) and its 1'-hydroxy metabolite, dill apiol (1-allyl-2,3-dimethoxy-4,5-methylenedioxybenzene), parsley apiol (1-allyl-2,5-dimethoxy-3,4-methylenedioxybenzene), 1'-hydroxyallybenzene, 3'-hydroxyanethole, and benzyl and anisyl alcohols had no detectable activity for the initiation of hepatic tumors on administration to male mice prior to weaning. The acetylenic derivative 1'-hydroxy-2',3'-dehydroestragole was much more active than either 1'-hydroxysafrole or 1'-hydroxyestragole when administered to preweanling mice. The 2',3'-oxides of safrole, estragole, eugenol, and 1'-hydroxysafrole, which are metabolites of these alkenylbenzenes, had little or no activity in this test. The 2',3'-oxides of safrole and estragole and their 1'-hydroxy derivatives likewise had little or no activity for the induction of lung adenomas in female A/J mice or for the induction of tumors on repetitive injections s.c. in male Fischer rats. However, the 2',3'-oxides of safrole, estragole, eugenol, 1'-hydroxysafrole, and 1'-hydroxyestragole, when administered topically to female CD-1 mice at relatively high doses, initiated benign skin tumors that could be promoted with croton oil.

Administration, Oral↗
PubMed1982

[Screening of diabetes in pregnancy. Standard value criteria for 50g-oGTT and fasting blood sugar as simple screening parameter with high accuracy].

Standard value criteria are presented on the basis of 1313 50g-oGTT for assessing carbohydrate metabolism in pregnancy (after the 26th week). The causes of the pregnancy-specific low levels are discussed. The difficulties in comparing these values with those reported by other authors, are pointed out. The authors deal extensively with the various load doses, conditions determining the decrease and glucose determination methods, and attempt to correlate the results with other data. The authors recommend fasting blood sugar values as a simple screening parameter for selecting those pregnant women on whom oGTT would be performed. This results in almost 90% coverage for pathological carbohydrate tolerance, i.e. a result which is superior to the results obtained with all other methods communicated so far. With this method, every 15th pregnant woman is required to undergo a costly and time-consuming test.

Berlin↗
PubMed1982

Rapid release of carcinogen-guanine adducts from DNA after reaction with N-acetoxy-2-acetylaminofluorene or N-benzoyloxy-N-methyl-4-aminoazobenzene.

Reaction of N-benzoyloxy-N-methyl-4-aminoazobenzene (N-benzoyloxy-MAB) or N-acetoxy-N-acetyl-2-aminofluorene (N-acetoxy-AAF), model ultimate aromatic amine or amide carcinogens, with [purine-14C]DNA at pH 7.4 or reaction of N-hydroxy-2-aminofluorene (N-hydroxy-AF) at pH 4.6 resulted in the rapid release of 14C-containing products not precipitable with the DNA. Four such products were obtained on reaction with N-acetoxy-AAF, two with N-hydroxy-AF, and six with N-benzoyloxy-MAB. Depending on the DNA sample used, the total amounts of 14C in these products from the reactions with N-benzoyloxy-MAB or N-acetoxy-AAF ranged from about 5% to as much as 30-40% of the amounts in the N-(deoxyguanosin-8-yl)-MAB or N-(deoxyguanosin-8-yl)-AFF residues in the DNA from the same reaction mixtures. Reactions with N-acetoxy-[acetyl-3H]AAF showed that the two major products retained the amide residue from the N-acetoxy-AAF. When the reactions were carried out with [guanine-(8-3H; 8-14C); adenine-(2,8-3H; 8-14C)]DNA, the two major products formed from N-acetoxy-AAF and four products formed from N-benzoyloxy-MAB had very low 3H:14C ratios; these ratios were those expected for guanine derivatives which had lost the 8-3H. Studies on the major DNA adducts N-(deoxyguanosin-8-yl)-MAB and N-(deoxyguanosin-8-yl)-AAF indicated that the new adducts were not formed from these nucleosides. The data suggest that the two major AAF products and the four MAB adducts studied are guanine derivatives formed by depurination of N-7 substituted adducts in the DNA.

2-Acetylaminofluorene↗
PubMed1982

Labeled 1,N6-ethenoadenosine and 3,N4-ethenocytidine in hepatic RNA of mice given[ethyl-1,2(-3)H or ethyl-1(-14)C]ethyl carbamate (urethan).

Injection of a single dose of[ethyl-1,2(-3)H]or[ethyl-1(-14C]- ethyl carbamate into 12-day old male[C57BL/6 x C3H/He]F1 mice or of[ethyl-1,2(-3H]ethyl carbamate into adult male A/Jax mice resulted in the formation of labeled 1,N6-ethenoadenosine and 3,N4-ethenocytidine adducts in the hepatic RNA. These adducts were characterized by comigration on h.p.l.c. of 3H or 14C in enzymatic hydrolysates of the RNA with synthetic standards. Both the ethenoadenosine and ethenocytidine were further characterized by their conversion to acetylated products that comigrated with acetylated synthetic standards. The ethenoadenosine was also converted by anhydrous trifluoroacetic acid to a product that comigrated with synthetic 1,N6-ethenoadenine. The levels of adducts in the hepatic RNA 12 h after a single injection of 0.5-0.6 mg of ethyl carbamate/g body weight were 6-10 and 2-3 pmol/mg RNA of ethenoadenosine and ethenocytidine, respectively. No labeled ethenoadenosine or ethenocytidine could be detected in the hepatic RNA of mice given[1-14C]ethanol, an enzymatic hydrolysis product of ethyl carbamate. These data indicate that ethyl carbamate may be metabolically activated by dehydrogenation to vinyl carbamate and subsequent epoxidation of the latter compound as previously proposed. Vinyl carbamate epoxide may form etheno derivatives in a manner analogous to that demonstrated for chloroethylene oxide, an electrophilic metabolite of vinyl chloride. Vinyl carbamate has been shown to have the same spectrum of tumor induction as ethyl carbamate but to be much more active than the latter carcinogen.

Adenosine↗
PubMed1982

Cholangiocellular carcinomas induced in Syrian golden hamsters administered aflatoxin B1 in large doses.

The hepatocarcinogenicity of aflatoxin B1 (AFB1) was compared in male Syrian golden hamsters and inbred F344 rats. AFB1 was administered by gavage 5 days/week for 6 weeks at doses of 1 and 2 mg/kg body weight/day to rats and hamsters, respectively; rate did not survive beyond 3 weeks with doses of 2 mg/kg/day. After 6 weeks the animals either received no further treatment or were given 0.1% phenobarbital sodium in the drinking water. ATPase-deficient foci of hepatic parenchymal cells, neoplastic nodules, and hepatocellular carcinomas were observed in liver sections from AFB1-treated rats killed at 6, 14, or 23 weeks; they were not seen in sections from AFB1-treated hamsters killed at 6, 14, or 46 weeks. Each of the 50 AFB1-treated rats developed hepatocellular carcinomas by 46 weeks; many also had cholangiocarcinomas and mixed hepatocellular-cholangiocellular carcinomas. Hepatocellular carcinomas were found in only 2 of 49 AFB1-treated hamsters by 78 weeks. At this time cholangiocarcinomas were found in 15 hamsters, and microscopic cholangiomas were seen in all of the livers. Compared to the rat, the hamster was resistant to the hepatotoxic and hepatocellular carcinogenic effects of AFB1.

Adenoma, Bile Duct↗