Antimetastatic and antitumor activities of interleukin 10 in a murine model of breast cancer.

BACKGROUND: Interleukin 10 (IL-10) is a potent immunoregulatory cytokine. It inhibits some cell functions, including T-helper (Th1) cell activity (i.e., interleukin 2 and interferon gamma production), and stimulates other functions such as a natural killer (NK) activity. In mice, IL-10 suppresses tumorigenicity in a xenograft system using a nonmetastasizing hamster cell line. PURPOSE: We evaluated the antitumor and antimetastatic properties of IL-10 in syngeneic immunocompetent and immunocompromised murine hosts. METHODS: Using the plasmids pBMGneo and pBMGneo.IL-10, we transfected the highly malignant murine mammary tumor cell lines 410.4 and 66.1 (transfectants designated as 410.4-IL10 and 66.1-IL10, respectively) to stably express IL-10 (2-100 U IL-10/2.5 x 10(5) cells per 48 hours). Tumorigenic and metastatic activities of the parent and transfected cells w ere measured in immunocompetent, syngeneic BALB/cByJ mice as well as in immunocompromised C.B-17/IcrCrl-SCID/Beige mice. RESULTS: Tumor growth was completely inhibited following inoculations of 5 x 10(6)410.4-IL10 cells in immunocompetent, syngeneic BALB/cByJ mice. This inoculum contains 100 times the minimum cell number required for 100% tumor incidence. In contrast, tumor growth following the inoculation of parental 410.4 or 410.4-neo cells was progressive, resulting in death of animals from pulmonary metastases at days 40-50 and transplantation. The tumorigenicity of 66.1-IL-10, compared with that of its parent cell line, was also significantly abrogated by IL-10 expression. Furthermore, in immunocompetent mice, the metastatic potential of both 410.4-IL10 and 66.1-IL10 was also completely inhibited. In immunocompromised C.B-17/IcrCrl-SCID/BR or C.B-17/IcrCrl-SCID/Beige mice, subcutaneous implants of 410.4-IL10 grew progressively, but growth was inhibited significantly in comparison to that produced by the parental 410.4 or 410.4-neo cells. In spite of the more limited efficacy of IL-10 against tumor growth in immunocompromised mice, spontaneous metastasis of 410.4-IL10 cells in C.B-17/IcrCrl-SCID/BR mice was inhibited by 90%. When NK activity was suppressed by asialoGM1 ganglioside antibody in BALB/cByJ mice or in C.B-17/IcrCrl-SCID/Beige mice, the antimetastatic effect of IL-10 was lost. CONCLUSIONS: These data show for the first time that IL-10 is a potent antimetastatic agent that is effective in immunocompromised hosts. This effect thus appears to be relatively independent of T-cell function but is dependent on NK activity. In contrast, the inhibitory effect of IL-10 on tumorigenicity relies on T-cell function. IMPLICATIONS: Based on the recent observation of others that IL-10 has little toxicity when administered systemically to human volunteers and also on the findings of this study that it has antitumor and antimetastitic properties in mice, possible use of IL-10 in the treatment of human metastatic cancers deserves consideration.

Frequency-dependent prey-selection of predacious water bugs on Armigeres subalbatus immatures.

BACKGROUND & OBJECTIVES: The predatory behaviour with reference to the frequency-dependent prey-selection of the water bugs Sphaerodema annulatum Fabricius and S. rusticum Fabricius was studied in the laboratory using the IV instar larvae and pupae of Armigeres subalbatus as prey to ascertain their efficacy as predator of mosquito immatures. METHODS: Field collected adult morphs of the water bugs were allowed to predate on larvae and pupae provided in different ratios and densities as per the model of Greenwood and Elton' for a fixed time period. The data obtained on their predation rate were analysed with respect to the model parameters, lnV--the frequency independent component and b--the frequency dependent component of selection. RESULTS: It was found that the prey-selection was dependent on the relative numbers of prey available, favouring apostatic selection. The b values and lnV values for S. annulatum were 0.54 +/- 0.01 and 0.92 +/- 1.04 respectively whereas the corresponding values for S. rusticum were 0.71 +/- 0.03 and 0.17 +/- 1.57 respectively. INTERPRETATION & CONCLUSION: The selection of preys by the water bugs was dependent on the relative number of the prey forms and thus they are expected to predate on the form more abundant in a heterogeneous prey population and adversely affect the adult emergence.

Sublethal oxidative stress inhibits tumor cell adhesion and enhances experimental metastasis of murine mammary carcinoma.

We have postulated that murine mammary tumor progression is fueled, in part, by tumor-associated macrophages that deliver sub-lethal oxidative stress to tumor cells. In the present study, we determined whether oxidative stress would affect murine mammary tumor cell attachment to laminin and fibronectin, critical functions in the metastatic process. Sublethal oxidative stress generated by exposure of cells to hydrogen peroxide (H2O2, 1-1000 microM/L) inhibited tumor cell attachment to immobilized laminin or fibronectin. This oxidant effect was blocked in the presence of catalase which removes H2O2. The inhibitory effect on attachment was rapid, with significant inhibition occurring at 5 min; total inhibition was achieved at 60 min with 1 mM H2O2. The oxidative stress effect was partially reversible at 20 h post-treatment and occurred at concentrations of H2O2 that do not adversely affect cell viability or growth. Pretreatment of tumor cells with H2O2 or hypoxanthanine and xanthine oxidase (to generate superoxide radical and H2O2) prior to intravenous injection, enhanced experimental lung tumor colony formation. The enhancement of experimental metastatic potential with enzyme-generated oxidative stress was completely reversed by catalase; the H2O2-mediated enhancement was only partially reversed with catalase. Thus, treatments that inhibit tumor cell attachment to extracellular matrix proteins in vitro enhance experimental metastasis in vivo.

Optimizing the HIV/AIDS informed consent process in India.

BACKGROUND: While the basic ethical issues regarding consent may be universal to all countries, the consent procedures required by international review boards which include detailed scientific and legal information, may not be optimal when administered within certain populations. The time and the technicalities of the process itself intimidate individuals in societies where literacy and awareness about medical and legal rights is low. METHODS: In this study, we examined pregnant women's understanding of group education and counseling (GEC) about HIV/AIDS provided within an antenatal clinic in Maharashtra, India. We then enhanced the GEC process with the use of culturally appropriate visual aids and assessed the subsequent changes in women's understanding of informed consent issues. RESULTS: We found the use of visual aids during group counseling sessions increased women's overall understanding of key issues regarding informed consent from 38% to 72%. Moreover, if these same visuals were reinforced during individual counseling, improvements in women's overall comprehension rose to 96%. CONCLUSIONS: This study demonstrates that complex constructs such as informed consent can be conveyed in populations with little education and within busy government hospital settings, and that the standard model may not be sufficient to ensure true informed consent.

New cyclopenta[a]naphthalene derivatives. Synthesis of 2-(carbamylmethyl)-8-hydroxy-3H-cyclopental[a]naphthalene as a possible deoxyribonucleic acid binding agent.

8-Methoxy-1-oxo-2,3-dihydro-1H-cyclopenta]a]naphthalene (4) was converted to the oxalyl derivative (7) by treatment with diethyl oxalate in the presence of sodium ethoxide. Compound 7 in the form of the sodium salt was alkylated with ethyl bromoacetate in DMF to 2-(carbethoxymethyl)-8-methoxy-1-oxo-2,3-dihydro-1H-cyclopenta[a]naphthalene (8). Treatment of 8 with methanolic ammonia yielded the corresponding amide (9). Dealkylation of 8 with 48% HBr and subsequent esterification gave compound 10. Ammonolysis of 10 led to the amide 11, which after reduction and subsequent dehydration of the reduced product afforded the desired compound, 2-(carbamylmethyl)-8-hydroxy-3H-cyclopenta[a]naphthalene (2). Compound 2 was found to be mildly growth inhibitory to L1210 and CCRF--CEM leukemic cells in culture. From thermal transition temperature studies, compound 2 was found to bind to calf thymus DNA and the poly(deoxyribonucleotides), e.g., poly(dG).poly(dC), poly(dG-dC), poly(dA).poly(dT), and poly(dA-dT).

Cyclopenta[f]isoquinoline derivatives designed to bind specifically to native deoxyribonucleic acid. 2. Synthesis of 6-carbamylmethyl-8-methyl-7(5)H-cyclopenta[f]isoquinolin-3(2H)-one and its interaction with deoxyribonucleic acids and poly(deoxyribonucleotides).

3-Ethoxy-8-methyl-5,6-dihydro-7H-cyclopenta[f]isoquinolin-5-one (2) was converted to 6-carbethoxymethyl-3-ethoxy-8-methyl-5,6-dihydro-7H-cyclopenta[f]isoquinolin-5-one (6) through an oxalyl derivative. Treatment of 6 with ammonia gave the corresponding amide 7 which on sodium borohydride reduction and subsequent dehydration yielded 6-carbamylmethyl-3-ethoxy-8-methyl-7(5)H-cyclopenta[f]isoquinoline (9). The analogous ester 10 was similarly obtained from 6. Numerous attempts to dealkylate the 3-ethoxy group of 9 or 10 failed. However, 6 coould easily be dealkylated on heating with 25% hydrochloric acid in a sealed tube.The ester, 6-carbethoxymethyl-8-methyl-5,6-dihydro-7H-cyclopenta[f]isoquinoline-3(2H),5-dione (11), so obtained was converted to the corresponding amide 12 which on reduction with sodium borohydride and subsequent dehydration afforded the desired compound, 6-car-bamylmethyl-8-methyl-7(5)H-cyclopental[f]isoquinolin-3-(2H)-one (1). 1 was found to be mildly cytotoxic againstL5178Y mouse leukemia cells in culture.1 was also found to bind to native calf thymus DNA. 1 inhibited RNA synthesis by a DNA-dependent RNA polymerase and a higher inhibition of RNA synthesis was observed when poly(dG-dC) was used as a template than when poly(dA-dT) was used. A significant increase of thermal transition temperature of calf thymus DNA and poly(dG)-poly(dC) was observed in the presence of 1. The accumulated evidence demonstrates that 1 interacts weakly with calf thymus DNA and interacts preferentially with poly(deoxyribonucleotides)-containing GC pairs.

Interaction of 5-ethynyl-2'-deoxyuridylate with thymidylate synthetase.

The interaction of 5-ethynyl-2'-deoxyuridylate (5-ethynyl-dUMP; 1) with thymidylate (dTMP) synthetase has been investigated. The compound was an inhibitor of the enzyme, competitive with 2'-deoxyuridylate (dUMP) when the reaction was initiated by addition of enzyme (Ki = 2.7 X 10(-6) M). However, upon preincubation of 1 with dTMP synthetase, the inhibition pattern became noncompetitive. The time course of the enzyme reaction in the presence of 1 was nonlinear, indicating an increase in binding with time. Irreversible inactivation of the enzyme did not occur. The compound did not appear to become altered structurally as a result of interaction with the enzyme. A ternary complex was formed among dTMP synthetase, compound 1, and 5,10-methylenetetrahydrofolate, which was stable enough to survive Sephadex G-25 filtration but dissociated upon denaturation of the enzyme.

Synthesis and biological activities of novel 5-(2-acylethynyl)uracils.

5-(2-Acylethynyl)-2,4-dimethoxypyrimidines (3-6) were synthesized in excellent yields from 2,4-dimethoxy-5-[2-(trimethylsilyl)ethynyl]pyrimidine (2) by treatment with acid chlorides in the presence of anhydrous aluminum chloride. Compounds 3-6 were deblocked with chlorotrimethylsilane and sodium iodide in acetonitrile to the corresponding 5-[(2-acyl-1-iodo)vinyl]uracils (7-10), which on treatment with potassium hydroxide in dioxane yielded the corresponding 5-(2-acylethynyl)uracils (11-14). The 5-(2-acylethynyl)uracils were found to be active against Ehrlich ascites carcinoma (EAC) cells in vivo, the most active compounds being 5-(2-benzoylethynyl)uracil (11) and 5-(2-p-toluoylethynyl)uracil (12). The T/C values of 281 and 300 were obtained for compounds 11 and 12, respectively, in the case of mice bearing EAC cells. The 5-(2-acylethynyl)uracils have also shown in vitro activity against CCRF-CEM and L1210/0 tumor cell lines. The lead compound 5-(2-p-toluoylethynyl)uracil effectively inhibited thymidylate synthetase.

Cyclopenta[f]isoquinoline derivatives designed to bind specifically to native deoxyribonucleic acid. 1. Synthesis of 3-ethoxy-8-methyl-7(5)H-cyclopenta[f]isoquinoline.

By the use of space-filling models, a novel compound, 6-carbamylmethyl-8-methyl-7(5)H-cyclopenta[f]isoquinolin-3-(2H)-one was devised which would be expected to hydrogen bond specifically to GC pairs in the major groove of the double helix such that (i) the amino group of the cytosine molecule donates a hydrogen bond to the C-3 carbonyl of the isoquinoline moiety and (ii) the amide proton of the side chain donates a hydrogen bond to the N-7 of guanine. 3-Ethoxy-8-methyl-7(5)H-cyclopenta[f]isoquinoline (4) which constitutes the basic ring system of 1 was synthesized in a multistep procedure starting from m-methyl-N-acetylbenzylamine (5). Friedel-Crafts reaction of 5 led to 2,4-bis(chloromethyl)-5-methyl-N-acetylbenzylamine (6) which on treatment with KCN, hydrolysis of the resultant nitrile, and subsequent esterification afforded 6-carbethoxymethyl-7-methyl-1,2,3,4-tetrahydroisoquinolin-3-one (9). Treatment of 9 with triethyloxonium fluoborate followed by dehydrogenation of the product gave 6-carbethoxy-methyl-3-ethoxy-7-methylisoquinoline (14). Chain extension of 14 followed by cyclization led to 3-ethoxy-8-methyl-5,6-dihydro-7H-cyclopenta[f]isoquinolin-5-one (19) which on reduction and subsequent dehydration yielded 3-ethoxy-8-methyl-7(5)H-cyclopenta[f]isoquinoline (4).

IL-10 gene transfer to intracranial 9L glioma: tumor inhibition and cooperation with IL-2.

This study examines the effects of interleukin-10 (IL-10) and combination IL-10 + IL-2 gene transfer on experimental brain tumor growth in vivo. 9L gliosarcoma cells were engineered to stably express murine IL-10 (9L-IL-10 cells) and implanted subcutaneously or to the caudate/putamen of syngeneic rats. The growth of tumors expressing IL-10 was substantially reduced compared to that of control tumors (p < 0.05). Intracranial tumors expressing IL-10 and IL-2 were established by co-implanting 9L-IL-10 cells with endothelial cells engineered to express IL-2. At 14 days post-implantation, tumors expressing IL-10 + IL-2 were 99% smaller than control-transfected tumors (p < 0.0001). This extent of anti-tumor effect could not be achieved by expression of IL-10 or IL-2 alone within tumors. Neither IL-10 nor a combination of IL-10 + IL-2 gene delivery inhibited tumor growth in severe combined immunodeficient (SCID-Beige) mice (p > 0.05). Immunohistochemical analysis revealed that IL-10 + IL-2 gene delivery markedly increased T-cell infiltration within the striatum ipsilateral to tumor cell implantation. These findings establish that IL-10 expression, particularly in combination with IL-2 expression, can have significant immune-dependent anti-tumor actions within intracranial gliomas.

Sequential determination of serum human placental lactogen, estriol, and estetrol for assessment of fetal morbidity.

Serial measurements were made of the concentrations of maternal serum human placental lactogen (hPL) (300 determinations), estriol (E3) (460 determinations), and estetrol (E4) (275 determinations) in normal human pregnancy during the third trimester period. Simultaneous determinations of serum hPL, E3, and E4 were also made sequentially on blood samples from 6 diabetic and 5 toxemic pregnant women to ascertain the relative usefulness of these parameters as indicators of fetal welfare. In uncomplicated diabetic patients controlled with insulin, all parameters increased with gestational age. In three pregnancies complicated by severe toxemia in which fetal distress progressed to intrauterine fetal death, both serum E3 and E4 levels decreased progressively, but E4 concentration started to decrease at least 1 day earlier than E3 prior to fetal death. In other women, the E4 levels appeared to drop or decrease significantly whereas the E3 levels remained almost unchanged. Daily hPL levels remained low in chronic fetal distress and, therefore, appeared to be of minimal value for predicting either intrauterine death or acute fetal distress. Therefore, serum E4 measurement seems to provide a more sensitive and reliable indicator of fetal morbidity than the measurement of serum E3 during toxemic pregnancies.

Comparison of serum unconjugated estriol and estetrol in normal and complicated pregnancies.

It has been reported that determinations of maternal serum unconjugated estriol (E3) and estetrol (E4) concentrations provide clinicians with more or less identical information on fetal status. If this is true, then theoretically the levels of E3 should be equally correlated with those of E4 in all conditions of pregnancy. To resolve this question, a study of the relationship between E3 and E4 was performed before labor in normal and complicated pregnancies. In normal pregnancy, they were highly correlated (r = .683, P less than .0001); in complicated cases, they were still correlated, but at a lower level (r = .522, P less than .003). To determine the effect of labor on this correlation, E3 and E4 levels were measured in normal subjects during labor as well as in the corresponding fetuses. The correlations between material E3 and E4, maternal and fetal E4, maternal and fetal E3, and fetal E3 and E4 were highly significant. A similar study with complicated pregnancies, however, indicated no such correlation except between fetal E3 and E4. In addition, day-to-day variability of serial measurements of E3 and E4 on an individual basis was determined in normal and diabetic subjects. The variability was qualitatively determined graphically and quantitatively determined algorithmically. The results of calculated individual variabilities indicated that the variability of E4 was less than that of E3 in most cases. It is therefore concluded that complications in pregnancy and the onset of labor have some effect on E3-E4 correlations, and that measurement of E4 has an additional advantage due to less variability.

Fetal and maternal serum copper levels before and during labor in normal and complicated pregnancies.

The effect of labor on maternal serum copper levels was determined in normal and complicated pregnancies. The mean value +/- SD (3.16 +/- 0.48 micrograms/ml) in 82 clinically normal subjects at term during labor was compared with that (2.22 +/- 0.49 micrograms/ml) obtained from 50 controls matched for gestational age who were not in labor. Similarly, the mean value in labor (3.56 +/- 0.46 micrograms/ml) in 25 subjects with a complicated pregnancy was compared with that (2.87 +/- 0.43 micrograms/ml) obtained from 25 similar subjects prior to labor. A statistically significant difference (P less than .001) was observed in both comparisons. Copper levels in the corresponding fetal serum from the subjects in labor (normal and complicated) were compared with those of the maternal serum samples. The mean value of fetal serum samples in mothers with complications was higher than that in normal mothers, but the difference was not statistically significant. This trend of a rise in serum copper level during labor was further confirmed by analysis of the same subject during and before labor in normal (12 subjects) and complicated pregnancies (9 subjects). Moreover, maternal serum estriol and estetrol levels were determined from the same samples in the 4 groups to find a possible relationship with the corresponding copper levels. No statistically significant correlation was noted. A possible explanation for the rise of the serum copper level with the onset of labor and its clinical implications are also discussed.

A multifactorial pregnancy outcome index.

In the present study pregnancy outcome is defined as a combination of seven relatively independent factors. Outcome scores were assigned to each subject on the basis of the number of pregnancy and labor-related factors that were satisfied. An outcome index of seven indicated an excellent outcome, and an index value of zero indicated the poorest outcome. Clinical data for 821 subjects, including a selected sample of 102 high-risk patients, were recorded using the Hollister Record System forms. The contribution of each of these factors to the overall outcome was estimated by statistical analysis of all data from the 821 subjects. Validation of this multifactor index of pregnancy outcome was obtained by correlation analysis with established factors such as the number of previous term pregnancies, live births, abortions, and present preexisting risk factors. In addition, retrospective analyses relating pregnancy outcome index with maternal serum unconjugated estriol, zinc, and copper obtained from 102 high-risk patients, revealed that copper level at all third trimester gestations was systematically and significantly related to outcome level while no such relationship emerged from comparisons with estriol and zinc. Good and poor outcomes were related to low and high copper values, respectively. The results of this exploratory study suggest that maternal serum copper levels may be an alternative predictor of pregnancy outcome.

Normal thrombin binding leads to greater fibrinogen binding and increased platelet aggregation in spontaneously hypertensive rats.

This study was conducted to determine the mechanisms of increased platelet reactivity to thrombin in hypertension. Thrombin induced significantly greater platelet aggregation in spontaneously hypertensive (SHR) than in normotensive (Wistar Kyoto, WKY) rats. Fibrinogen and thrombin binding to platelets was determined using [125I]-fibrinogen and [125I]-thrombin respectively. Increased platelet aggregation in SHR correlated with thrombin-induced greater binding of fibrinogen to SHR than to WKY platelets. However, the number of thrombin receptors (binding sites/platelet) in WKY (19,500 +/- 3,000) and SHR (23,100 +/- 3,000) as well as thrombin dissociation constants were statistically similar in WKY (1.17 +/- 0.2 microM) and SHR (1.62 +/- 0.27 microM) platelets. Fura 2/AM, a fluorescent calcium indicator, loaded platelets were used to quantify the platelet ionized calcium ([Ca2+]i). The [Ca2+]i in unstimulated SHR and WKY platelets was essentially the same. In a calcium poor medium, thrombin-induced a 35% greater increase in [Ca2+]i in SHR than in WKY platelets. These data, taken together with our earlier observations that thrombin induces a significantly greater hydrolysis of phosphoinositide (Thromb. Res. 49, 5-21, 1988), lead us to suggest that thrombin-induced increased generation of inositol 1,4,5-trisphosphate and diacylglycerol induces greater fibrinogen binding and consequently increased aggregation in SHR than WKY platelets. The finding that the thrombin binding isotherms are similar in WKY and SHR platelets suggests that increased platelet sensitivity to thrombin in hypertension may be due to altered signal transduction and not due to changes in the number or affinity of thrombin receptors.

Radioimmunoassay of 15alpha-hydroxyestriol (estetrol) in pregnancy serum.

A more specific antisera against 15alpha-hydroxyestriol (estetrol) was produced in rabbits by immunization with 6-oxoestetrol-6-carboxy-methyloximino-bovine serum albumin. The synthesis of estetrol tetraacetate was greatly improved. Characterization of estetrol antisera revealed that it is more specific than those formerly obtained. A simple method of extraction of estetrol with alcohol from serum with high recovery is described. A radioimmunoassay method for pregnancy serum is characterized in regard to its specificity, accuracy, sensitivity and precision. The method is able to measure as little as 50 pg/tube or 167 pg/ml of serum. The intraassay coefficient of variation is 7.8% and that for interassay including personnel variation is 14.2%. Accuracy of the method, as determined by the recovery of non-radioactive estetrol (1 ng/ml) added to non-pregnancy serum, is found to be 89 +/- 8 (SD)%, CV = 8.7%, without correction for experimental losses. One hundred twelve pregnancy sera were analysed; the values obtained from normal subjects in the third trimester ranged from 240-950 pg/ml. The values obtained by this method are somewhat lower than those reported previously, presumably due to the higher specificity of the antibody.

Salivary unconjugated estriol levels in normal third trimester pregnancy - direct correlation with serum levels.

A radioimmunoassay for salivary unconjugated estriol concentration during the third trimester of normal pregnancy is described. The performance characteristics of the method were established by determining the non-specific binding, the blank value of the endogenous estriol free ("stripped") saliva, the recovery experiment and intra- and interassay coefficient of the variations. The corresponding serum samples were also analyzed by the same method. An excellent correlation was found between salivary and serum estriol concentrations.

Production of antisera against contraceptive steroids.

A four step synthesis of 6-(0-carboxymethyl) oximinoethynylestradiol is reported. This compound, 6-(0-carboxymethyl) oximinomestranol, the 3-(0-carboxymethyl) oximes of norethindrone and norgestrel and the 3-hemisuccinate of ethynylestradiol were synthesized and conjugated with bovine serum albumin. Rabbits were immunized at 3 dose levels of haptene (20, 66 and 200 nmoles) and eight weeks later with a booster containing 66 nmoles of haptene. The antibody titer and association constant of responding rabbits was nearly independent of dose although most antibody production occurred after the booster injection. Antibodies to mestranol crossreacted more than 100 percent with ethynylestradiol and to a small extent with norethindrone and norgestrel.

PIP: The methods of synthesis of the 6-(0-carboxymethyl) oxime derivative of 6-oxoethynylestradiol-17beta, the 3-succinyl derivative of ethiny estradiol-17beta and the 3-carboxymethyl oxime derivative of norethindrone and norgestrel as well as the synthesis of the corresponding bovine serum albumin (BSA) conjugates required for the specific antisera for mestranol, ethinyl estradiol, norethindrone, and norgestrel in rabbits are described. The synthesis of 6-(0-carboxymethyl) oxime derivative involves a 4-step synthesis and a chromatographic purification which is an improvement over past methods. Conjugation to BSA was by the carbodiimide method. Response of immunization was measured in terms of titer, association constant, and cross-reactivity as a function of time after immunization with 3 dose levels of each antigen. Titer response was independent of dose for the original injection. Ethiny estradiol-3-conjugates had very low titers.

N-Alkylated derivatives of 5-fluorouracil.

Some N-alkyl derivatives of 5-fluorouracil were designed to act as latent depot forms of 5-fluorouracil. A general and efficient method for the syntheses of the alkylated derivatives is described. As expected, the alkylated derivatives of 5-fluorouracil did not show any cytotoxicity in cell culture systems even up to 10(-4) M concentration. The synthesis of 1,3-dimethyl-5-fluoro-5,6-dihydrouracil is also described.

Expression of the RET/PTC fusion gene as a marker for papillary carcinoma in Hashimoto's thyroiditis.

Hashimoto's thyroiditis is an inflammatory disease of the thyroid gland with autoimmune etiology. Patients afflicted with Hashimoto's have a higher risk of thyroid malignancies such as papillary thyroid carcinoma. In the present study, we investigated the frequency of papillary thyroid carcinoma specific genes in patients diagnosed with Hashimoto's disease. The newly identified oncogenes RET/PTC1 and RET/PTC3 provide useful and specific markers of the early stages of papillary carcinoma as they are highly specific for malignant cells. Using a sensitive and specific reverse transcriptase-polymerase chain reaction (RT-PCR) assay, we found messenger RNA (mRNA) expression for the RET/PTC1 and RET/PTC3 oncogenes in 95% of the Hashimoto's patients studied. All Hashimoto's patients presenting without histopathologic evidence of papillary thyroid cancer showed molecular genetic evidence of cancer. These data suggest that multiple, independent occult tumors exist in these patients at high frequency.