Increased urinary excretion of 2-hydroxyestrone but not 16alpha-hydroxyestrone in premenopausal women during a soya diet containing isoflavones

Asian diets high in soy are associated with lower risk for breast cancer compared with Western diets. Moreover, higher levels of two putative carcinogenic metabolites of 17beta-estradiol, 4- and 16alpha-hydroxyestrogen, and lower amounts of anticarcinogenic metabolites, 2-hydroxyestrogens, have been associated with greater breast cancer risk. In this study, we tested the hypothesis that consumption of a soya diet containing the weakly estrogenic isoflavones genistein and daidzein may alter the metabolism of 17beta-estradiol to 2- and 16alpha-hydroxylated products. Eight pre-menopausal women were placed on a soya-containing, constant diet in a metabolic unit. The diet provided 400 kilocalories from soymilk and 113-202 mg/day (158 +/- 26 mg/day, mean +/- SD) isoflavones daily for a complete menstrual cycle. After a washout period of 4 months, the subjects consumed the same diet, but with soymilk that contained <4.5 mg/day isoflavones ("isoflavone-free"). Urine samples were collected for 24 h daily for the entire cycle during each soya diet period for the analysis of daidzein, genistein, and 2- and 16alpha-hydroxyestrone. Subjects excreted measurable amounts of daidzein (11.6-39.2 mg/day) and genistein (2.9-18.2 mg/day) during the isoflavone-rich soya diet but not during the isoflavone-free soya diet. The diet rich in isoflavones increased the cycle mean daily urinary excretion of 2-hydroxyestrone (averaged over the entire cycle) from 11.6 +/- 2.06 to 17.0 +/- 2.96 nmol/12-h (P = 0.03), a 47% increase. However, the mean daily excretion of 16alpha-hydroxyestrone did not change (7.0 +/- 1.14 nmol/12-h during the isoflavone-free and 7.7 +/- 1.25 nmol/12-h during the isoflavone-rich diet; P = 0.36). The ratio of 2-hydroxyestrone to 16alpha-hydroxyestrone was higher during the isoflavone-rich soya diet (2.6 +/- 0.34) than during the isoflavone-free diet (2.0 +/- 0.32; P = 0.01), a 27% increase. These results suggest that soya isoflavones increase the metabolism of endogenous estrogens to the protective 2-hydroxylated estrogens in women, and this may play an important role in lowering 17beta-estradiol levels and the long-term risk for breast cancer.

Synthesis and antitumour activity of novel diterpenequinone salvicine and the analogs

A novel diterpenequinone named salvicine (4), structurally modified derivative of a natural product, and a series of the novel analogs have been prepared. Most of the analogs were found to be potently active against tumor cell lines in vitro. Further study on 4 in vivo demonstrated that it possessed a significant antineoplastic activity against murine S-180 Sarcoma and Lewis lung cancer, and human lung adenocarcinoma xenografts A-549 and LAX-83. The preclinical studies of 4 are now under way.

A nonisotopic enzyme-based immunoassay for assessing human exposure to genistein

Phytoestrogenic isoflavones that are abundant in soybeans may be an important group of natural products that could play a critical role in preventing several chronic human diseases. To facilitate studying the relationship of soya exposure and chronic diseases, we report a simple method for measuring an isoflavone, genistein, in human urine and plasma. The method is a competitive enzyme-linked immunoassay that utilizes a conjugate of horseradish peroxidase (HRP) and genistein as tracer and a monoclonal antibody to genistein (clone 10D8) generated through the 6-position of genistein. Genistein, in diluted hydrolyzed urine or plasma of subjects who ingested soy milk, competes with HRP-genistein conjugate for the binding sites of anti-genistein antibody on rabbit anti-mouse IgG-coated plates. After a one-hour incubation, the wall-bound genistein-HRP activity, after reaction with a chromogen, is measured colorimetrically at 450 nm and is inversely correlated with concentrations of genistein over the range of 0.1-32 ng/well. The sensitivity limit of the method is 0.5 ng of genistein per well or 0.5 ng per 10 microliters of urine and plasma. Urine and plasma levels of genistein measured by this immunoassay correlated well (R2 = 0.92 for urine and 0.77 for plasma) with those determined by chromatographic techniques. This method can be used to assess soya exposure in humans and could facilitate epidemiological studies of the relationship of soya diets and chronic diseases, including cancer.

Sex and long-term soy diets affect the metabolism and excretion of soy isoflavones in humans

Soybean consumption may be protective against hormone-dependent cancers, possibly in part because of the isoflavones daidzein and genistein, which are weakly estrogenic. This paper reviews our studies of the metabolism and disposition of these phytoestrogens in humans. During 1 mo of daily soy ingestion in a metabolic unit [1.065 L (36 oz) soymilk, providing 80-210 mg of each isoflavone daily], women initially excreted more isoflavone conjugates in urine than did men. Recoveries of conjugates of genistein, daidzein, and equol were 24%, 66%, and 28% of the amounts ingested in women, respectively, and 15%, 47%, and 15%, respectively, of those in men. A progressive decrease in urinary excretion of genistein and daidzein was observed in women but not in men during the study. At least 10% of ingested daidzin was excreted in urine as equol conjugate in one man and one woman after the first soy ingestion. Three more women but no more men developed the ability to produce and excrete large amounts of equol. Absorption rate constants (k(e)) of the isoflavones were estimated to be 0.24-0.50 h(-1). The elimination rates (k(e)) for genistein, daidzein, and equol were 0.1, 0.16, and 0.08 h(-1), respectively, in women and 0.19, 0.25, and 0.13 h(-1), respectively, in men. Thus, the excretion half-life values of genistein were longer in women (7, 4, and 9 h, respectively) than in men (4, 3, and 5 h, respectively) after the first soy ingestion. The excretion half-life shortened progressively in women but lengthened progressively in men over the study period. Thus, isoflavone metabolism and disposition were affected by the duration of soy ingestion and by sex.

The measurement of the isoflavone daidzein by time resolved fluorescent immunoassay: a method for assessment of dietary soya exposure

We report a novel method for the measurement of urinary daidzein that is suitable for assessment of dietary soya exposure. The method incorporates the following features: (i) a highly specific monoclonal antibody to daidzein (clone 4E4) raised through the 7 position of daidzein and (ii) a europium labeled ovalbumin daidzein conjugate. In the present format, dilute urine samples of subjects who ingested soy milk are hydrolyzed with beta-glucuronidase for 30 min on rabbit anti-mouse coated plates. Afterwards, the specific monoclonal antibody to daidzein, clone 4E4, and europium labeled ovalbumin daidzein conjugate are added. After 1 h incubation, the wall bound fluorescence of europium is measured by time resolved fluorescence and is inversely proportional to the concentration of daidzein over the range 0.1-10 ng daidzein/well. The method demonstrates good sensitivity, precision and comparability with the chemical method GC-FID. Unlike the chemical method, the present immunoassay technique for daidzein is applicable for the measurement of large amounts of samples in epidemiological studies for the assessment and monitoring of human exposure to soya food.

Prefocusing optics for soft-x-ray synchrotron-radiation monochromators

We present a mirror system to be used for the prefocusing optics of soft-x-ray monochromators using synchrotron radiation from a bending magnet source. The system consists of a cylindrical and a toroidal mirror arranged coplanarly. It can be made, by proper selection of the curvature radii of the mirrors, free of astigmatic coma. The design method is described in detail; the system is evaluated by exact ray-tracing calculations. Also given is a design example of the prefocusing optics in a soft-x-ray synchrotron radiation be aniline.

Establishment of a human acute promyelocytic leukemia-ascites model in SCID mice

Acute promyelocytic leukemia (APL) is an interesting model for cancer research because of the presence of the specific PML-RARalpha fusion gene associated with the clinical response to retinoic acid differentiation therapy. To better understand and improve differentiation induction with retinoic acid, we have established a human APL-ascites model in SCID mice using the NB4 human APL cell line. NB4 (1 x 10(6) cells) were transplanted into the peritoneum (IP) of SCID mice for 1 month. NB4 ascites cells (A-NB4) appeared, which were then engrafted in SCID mice periodically for 18 passages at an interval of 3 to 4 weeks with a 100% success rate of tumor induction. The mean survival times of SCID mice transplanted with 1 x 10(6) A-NB4 cells was 21.6 +/- 2.3 days. Analysis of the biologic characteristics of ninth passage NB4 ascitic cells was performed and they were found to have the morphologic, immunologic, cytogenetic, and molecular features of cultured NB4 cells. Furthermore, A-NB4 cells were capable of differentiating when treated with all-trans retinoic acid (ATRA), as manifested by enhanced NBT reduction and CD11b expression. In vivo treatment with ATRA in SCID mice for 4 days also increased NBT reduction by A-NB4 cells. ATRA treatment significantly prolonged survival time in the group after transplantation (28.1 +/- 6.8 to 29.1 +/- 8.4 days) compared with the control (P < .001). Furthermore, treatment with adriamycin, an effective chemotherapeutic drug in APL, had a strong growth suppressive effect on A-NB4 cells. These results demonstrate that this SCID-APL (NB4 ascites cells) model is a useful preclinical system for evaluating new or known drugs in the treatment of APL.

Effects of soya consumption for one month on steroid hormones in premenopausal women: implications for breast cancer risk reduction

Soybean consumption is associated with reduced rates of breast, prostate, and colon cancer, which is possibly related to the presence of isoflavones that are weakly estrogenic and anticarcinogenic. We examined the effects of soya consumption on circulating steroid hormones in six healthy females 22-29 years of age. Starting within 6 days after the onset of menses, the subjects ingested a 12-oz portion of soymilk with each of three meals daily for 1 month on a metabolic unit. Daily isoflavone intakes were approximately 100 mg of daidzein (mostly as daidzin) and approximately 100 mg of genistein (mostly as genistin). Serum 17 beta-estradiol levels on cycle days 5-7, 12-14, and 20-22 decreased by 31% (P = 0.09), 81% (P = 0.03), and 49% (P = 0.02), respectively, during soya feeding. Decreases persisted for two or three menstrual cycles after withdrawal from soya feeding. The luteal phase progesterone levels decreased by 35% during soya feeding (P = 0.002). Dehydroepiandrosterone sulfate levels decreased progressively during soya feeding by 14-30% (P = 0.03). Menstrual cycle length was 28.3 +/- 1.9 days before soymilk feeding, increased to 31.8 +/- 5.1 days during the month of soymilk feeding (P = 0.06), remained increased at 32.7 +/- 8.4 days (P = 0.11) at one cycle after termination of soymilk feeding, and returned to pre-soya diet levels five to six cycles later. These results suggest that consumption of soya diets containing phytoestrogens may reduce circulating ovarian steroids and adrenal androgens and increase menstrual cycle length. Such effects may account at least in part for the decreased risk of breast cancer that has been associated with legume consumption.

Altered kinetics and extent of urinary daidzein and genistein excretion in women during chronic soya exposure

Soybean consumption may be protective for breast cancer, possibly due in part to the presence of the isoflavones daidzein and genistein, which are weakly estrogenic. The metabolism and disposition of these phytoestrogens during chronic soya exposure were studied on a metabolic unit. Six healthy 22- to 29-year-old women consumed an unrestricted hospital diet for most of the study and ingested 12 oz of soymilk with each meal for one month. At two-week intervals, excretion of isoflavones in urine was studied, during which time the subjects consumed a constant basal diet for three to four days, ingested the full daily 36-oz portion of soymilk within 30 minutes each day for one to two days, and collected urine continuously. Urinary recovery of genistein [initially 23.9 +/- 17.3% (SD) of ingested genistin + genistein], daidzein (initially 66.2 +/- 23.5% of ingested daidzin + daidzein), and equol (initially 28% of the ingested precursors daidzin + daidzein in 1 subject and < 1% in 5 subjects) decreased progressively over four weeks of daily soya ingestion by 42% for genistein (p < 0.05) and 31% for daidzein (p < 0.01) but increased by 3- to 100-fold for equol (4 subjects, p < 0.05). Total amounts excreted and peak levels were similarly affected. The absorption half-lives (t 1/2) for genistein and daidzein were initially 2.7 +/- 0.8 and 1.6 +/- 0.5 hours, respectively, and during four weeks of soymilk ingestion decreased to 2.0 +/- 0.6 (p = 0.04) and 1.4 +/- 0.2 hours (p = 0.06), respectively, suggesting more rapid absorption. The appearance t 1/2 of equol can be estimated for only one subject initially (2.9 hrs), but during four weeks of soya ingestion it could be estimated for three more subjects (4.7 +/- 2.3 hrs). The excretion t 1/2 values for genistein and daidzein were initially 6.7 +/- 0.8 and 4.4 +/- 0.7 hours, respectively, and during four weeks of soymilk ingestion decreased to 4.2 +/- 1.2 (p = 0.005) and 3.2 +/- 1.1 hours (p = 0.005), respectively, suggesting more rapid excretion. For equol, the excretion t 1/2 was initially 9.1 hours (1 subject), and after two and four weeks of soymilk ingestion it was 13.4 +/- 9.7 and 5.5 +/- 1.6 hours (4 subjects, p = 0.046, 2 wks vs. 4 wks), respectively. These results indicate that metabolism and disposition of ingested isoflavones are altered during chronic soya ingestion in women, perhaps from increased metabolic degradation to formation of nonisoflavone metabolites. Increased production of the longer- and stronger-acting estrogenic equol in some women during chronic soymilk ingestion may alter the estrogenic potency of dietary soya isoflavones.

Coma correction and extension of the focusing geometry of a soft-x-ray monochromator

I show analytically and numerically how to use a varied line-space grating to reduce coma aberration in a soft-x-ray synchrotron radiation monochromator: a plane grating in combination with one or more spherical mirrors arranged in front of the grating and rotated around a fixed axis outside the mirror surface. It seems that the variation extent of groove spacing is too small to be manufactured; thus, a holographic grating of equivalent imaging properties is proposed. Based on the analysis of a focusing equation, I found that, if the plane grating is replaced by a spherical one, the monochromator can also be made free of defocus.

Characterization of a major latex allergen associated with hypersensitivity in spina bifida patients

Hypersensitivity to latex proteins present in health care products, particularly in latex gloves, has emerged as an important public health problem in recent years. Most of these latex allergens have not been purified or characterized. Here we report the purification and characterization of a 23-kDa latex polypeptide from nonammoniated natural rubber latex. This purified 23-kDa polypeptide reacted with IgE from 13 of 17 (76%) latex-allergic spina bifida patients, but from only 1 of 5 health care workers with latex allergy. Furthermore, all the sera of patients with anaphylaxis to latex showed reactivity with the 23-kDa polypeptide. This allergen also induced significant lymphocyte proliferation by PBMC from spina bifida patients, but not from health care workers. The 90 amino acid residues sequenced from the 23-kDa polypeptide showed a 45.6% homology with a previously reported latex protein, rubber elongation factor. By using a mAb LAM-1, produced against the 23-kDa allergen, we could also detect this allergen or its epitope in ammoniated latex and natural rubber latex products used in health care management, but not in non-latex extracts studied.

Characterization of a major latex allergen associated with hypersensitivity in spina bifida patients

Hypersensitivity to latex proteins present in health care products, particularly in latex gloves, has emerged as an important public health problem in recent years. Most of these latex allergens have not been purified or characterized. Here we report the purification and characterization of a 23-kDa latex polypeptide from nonammoniated natural rubber latex. This purified 23-kDa polypeptide reacted with IgE from 13 of 17 (76%) latex-allergic spina bifida patients, but from only 1 of 5 health care workers with latex allergy. Furthermore, all the sera of patients with anaphylaxis to latex showed reactivity with the 23-kDa polypeptide. This allergen also induced significant lymphocyte proliferation by PBMC from spina bifida patients, but not from health care workers. The 90 amino acid residues sequenced from the 23-kDa polypeptide showed a 45.6% homology with a previously reported latex protein, rubber elongation factor. By using a mAb LAM-1, produced against the 23-kDa allergen, we could also detect this allergen or its epitope in ammoniated latex and natural rubber latex products used in health care management, but not in non-latex extracts studied.

Genetic damage and the inhibition of 7,12-dimethylbenz[a]anthracene-induced genetic damage by the phytoestrogens, genistein and daidzein, in female ICR mice

Populations consuming soybeans have reduced rates of breast, colon and prostate cancer possibly due, in part, to the presence in soybeans of two estrogenic isoflavones, genistein and daidzein. This study investigated the genotoxicity of these soya isoflavones and their interactions with 7,12-dimethylbenz[a]anthracene (DMBA)-induced sister chromatid exchanges (SCE) in bone marrow cells and DNA adduct formations in liver and mammary glands of mice. Groups of female ICR mice were pretreated i.p. with daidzein and/or genistein (10-20 mg/kg per day for 6 days or 50 mg/kg per 12 h for 3 days) or with the solvent, dimethylsulfoxide (DMSO). The mice were implanted with bromodeoxyuridine (BrdU) tablets s.c., and treated with DMBA (50 mg/kg) i.p. and colchicine (4 mg/kg) i.p. 24, 23, and 2 h before sacrifice, respectively. In bone marrow cells. DMBA alone induced 11.73 +/- 1.42 SCE/cell compared to 4.35 +/- 0.83 SCE/cell in the DMSO treated controls (P = 0.001). DMBA induced 20% fewer SCE (P < 0.05) in mice pretreated with daidzein, genistein or a combination of genistein and daidzein (6 x 20 mg/kg per day for 6 days) when compared to mice that received no pretreatments. Genistein at 50 mg/kg per 12 h for 3 days also inhibited DMBA-induced SCE by 20%. However, treatment for 3 days with 50 mg/kg per 12 h of genistein or daidzein alone, or a combination of daidzein plus genistein (without DMBA treatment) also induced more SCE than treatment with only the solvent (DMSO, P < 0.05). Pretreatment with both the low and the high doses of daidzein plus genistein or the high dose of genistein reduced the replication index of bone marrow cells when compared to pretreatment with DMSO (P < 0.05). Pretreatment with genistein reduced DMBA-induced DNA adduct formation by 34%, but this was only marginally significant (P = 0.08) due to the large inter-individual variability in adduct levels. These results show that genistein and daidzein suppress SCE and possibly DNA adduct formation induced by the known carcinogen, DMBA. This response to a low dose isoflavone exposure may be partly responsible for the protective effect against endocrine cancers of soya consumption.

Comparison of latex antigens from surgical gloves, ammoniated and nonammoniated latex: effect of ammonia treatment on natural rubber latex proteins

Immediate hypersensitivity to latex proteins from contact with natural rubber latex gloves has been increasingly reported, especially in health care workers. Proteins in the latex responsible for these reactions may potentially be extractable, adsorbed on glove powder, or remain unextractable. Because these gloves are manufactured from ammoniated natural rubber latex, our knowledge on the effect of ammonia on latex proteins is incomplete. Therefore, we have investigated the effect of ammoniation on the protein profile and antigenicity or allergenicity of natural rubber latex proteins (NAL). Results indicate that ammonia treatment leads to breakdown and even precipitation of certain latex proteins. However, the antigenicity or allergenicity of NAL is preserved in the degraded proteins that present as extractable latex antigens of gloves. In addition to the proteins present in glove extract and proteins adsorbed to glove powder, certain latex proteins (23, 10, and 8 kd) remain firmly bound to glove film as "unextractable" latex antigens that cannot be removed by washing. The unextractable latex antigens may represent the antigens precipitated by ammonia treatment and may be associated with latex allergy.

A simplified method to quantify isoflavones in commercial soybean diets and human urine after legume consumption

Reliable and economical quantification of micronutrients in diets and human is a critical component of successful epidemiological studies to establish relationships between dietary constituents and chronic disease. Legumes are one of the major dietary components consumed by populations worldwide. Consumption of legumes is thought to play a major role in lowering breast and prostate cancer risk. In this study, a simplified method that uses solid-phase extraction and gas chromatography was developed to measure isoflavones at levels down to 10 micrograms/5ml. With the use of this method, 12.5 g miso (a soybean paste), 12 ounces Isomil, and 12 ounces soymilk had daidzin/daidzein levels of 2, 5, and 12.4 mg, respectively, and genistin/genistein levels of 3, 6.5, and 13.7 mg, respectively. In these products, most of the isoflavones were present as glucosides. With the same method, urinary levels of isoflavones in six 15-17-year-old subjects were determined after soymilk ingestion. Each subject was placed on unrestricted nonsoya diets, and three 12-ounce portions of soymilk were given at 12-h intervals. Males excreted 15.02 +/- 2.74 (SD) mg of daidzein glucuronides/sulfates [mean recovery, 40.4 +/- 7.4% (SD)] by 24 h after the third soymilk ingestion, whereas females excreted 25.56 +/- 5.10 mg (68.7 +/- 13.7%) of daidzein conjugates, which was more than males (P = 0.02). Males and females excreted 7.73 +/- 1.95 mg and 9.11 +/- 0.84 mg of genistein glucuronides/sulfates (20% recovery of genistin intake), respectively, in the urine. Most of the isoflavones were excreted within 24 h after ingestion.(ABSTRACT TRUNCATED AT 250 WORDS)

Monoclonal antibody against a major latex allergen reacts with latex products and ammoniated natural latex

Spina bifida patients have been shown to be a high-risk group for latex allergy. Of the several latex proteins identified from nonammoniated natural latex, a polypeptide with a molecular mass of about 23 kDa was shown to be one of the major allergens reacting with IgE in the sera from such patients. Using hybridoma technology, a monoclonal antibody (mAb) 1E2 against the 23-kDa latex allergen was produced. The presence of the 23-kDa or related allergens in finished latex products was evaluated using 1E2. Of the 16 extracts of finished latex products, 12 reacted with 1E2. The other four products are not used in health care. Since the majority of latex products used in health care are manufactured from ammoniated latex and ammoniation may alter latex proteins, we also investigated the effect of ammoniation on the 23-kDa allergen. Although ammoniation degraded latex proteins, the 23-kDa antigen could still be detected by using mAb 1E2 on immunoblot of ammoniated latex proteins. Furthermore, ammoniation resulted in the appearance of additional proteins in high molecular weight positions not present in nonammoniated natural latex, which retained the 23-kDa epitope. The 23-kDa allergen could also be detected on surgical gloves after extensive washing.

Decreased plasma levels of cholecystokinin in healthy males after chronic ingestion of a heat-treated soya product

Administration of raw soya containing a trypsin inhibitor stimulated excessive release of cholecystokinin (CCK) which led to pancreatic hypertrophy, hyperplasia and cancer in the rats (Booth et al. (1964) Proc. Soc. Exp. Biol. Med., 116, 1067). More postprandial CCK release in healthy humans was observed after ingestion of a single dose of raw soya than heat-treated soya (Calam et al. (1989) Br. J. Nutr., 58, 175). The effect of chronic ingestion of a heat-treated soya product on postprandial CCK release was investigated in six healthy adult males after ingestion of a 36-oz. portion of soymilk daily for 1 month and at 2-3 months after termination of soymilk ingestion. Subjects fasted for 15 h, ingested Lipomul (1.5 g/kg) and provided blood at timed intervals for CCK analysis. The results show that 1-month ingestion of soymilk decreased the magnitude of Lipomul-induced postprandial CCK release in plasma of all six subjects by 5-60% (P < 0.05) compared to those obtained at 2-3 months after the withdrawal from soymilk ingestion. Plasma pancreatic polypeptide (PP) levels were similarly decreased in five of the six subjects by 19-67% (P = 0.03) in line with the regulation of PP by CCK. Thus, prolonged exposure of humans to a heat-treated soya inhibited slightly meal-induced CCK release in contrast to that found in rats after raw soya diets.

Altered time course of urinary daidzein and genistein excretion during chronic soya diet in healthy male subjects

Soybean consumption is associated with reduced rates of prostate and other cancers, possibly due in part to the presence of isoflavones. The metabolism and disposition of these soya-derived phytoestrogens after chronic soya exposure were studied on a metabolic unit in six healthy males (21-35 yrs of age) who consumed an unrestricted hospital diet and a 12-oz portion of soymilk with each meal for one month. The daily isoflavone intake was about 100 mg of daidzein (mostly as diadzin) and about 100 of mg of genistein (mostly as genistin). At two-week intervals, excretion of isoflavones in urine was studied, during which time the subjects consumed a constant basal diet for three to four days, ingested the full daily 36-oz portion of soymilk within 30 minutes each day for one to two days, and collected urine continuously. The urinary recovery of ingested diadzin plus daidzein (46.9 +/- 15.2%, mean +/- SD) and genistin plus genistein (14.6 +/- 9.2%) did not change with prolonged soya ingestion. The absorption half-lives (t1/2) for daidzein and genistein and the appearance t1/2 for equol (1 subject) were initially 1.5 +/- 0.4, 1.9 +/- 0.6, and 2.2 hours, respectively, and 2.5 +/- 1.1 (p = 0.06 compared with baseline) 1.4 +/- 0.9 (p = 0.03) compared with baseline), and 4.2 hours, respectively, during one month of soymilk ingestion. The excretion t1/2 for daidzein, genistein, and equol were initially 2.9 +/- 0.5, 3.8 +/- 0.7, and 5.2 hours, respectively, and 3.9 +/- 1.2 (p - 0.03), 5.5 +/- 1.6 (p = 0.02), and 9.7 hours, respectively, during one month of soymilk ingestion. These results indicate that chronic soya exposure did not induce significant changes in the metabolic pathways of isoflavones but altered the time courses of daidzein and genistein excretion. Thus chronic exposure to soya might prolong the tissue exposure to the presumed biologically active free and unconjugated forms of these isoflavones and thereby enhance their oncoprotective effects.

[A bispecific monoclonal antibody with versatile adaptor mediating different cytotoxicities]

Bispecific monoclonal antibody (bsMAb), secreted by hybrid-hybridoma, has an intact 1g molecule construction with dual antigen binding specificities. bsMAb has several advantages over conventional conjugate in tumor targeting therapy: (1) The damage to both antibody and tumoricidal agents due to chemical crosslinking can be avoided. (2) The antigen modulation can be decreased due to monovalence binding of bsMAb with target antigen. (3) The binding affinity between Fc fragment of bsMAb with heterogenous heavy chains and Fc receptor is decreased, so that nonspecific distribution and side effects can be reduced. (4) The bsMAb can pretarget to tumor site, increasing the T/NT ratio and cytotoxicity. In the present study, A bsMAb with versatile adaptor was designed. In this bsMAb, one arm could react with gastric cancer-associated antigen, and the other with a hapten TNP. The bsMAb could mediate different tumoricidal agents crosslinked to TNP. A variant hybridoma 3H11-HAT(s) secreting McAb against gastric cancer was fused with spleen cells of mice immunized with KLH-TNP. After screening and subcloning, 10 hybrid-hybridomas were obtained, which secreted antibodies against both gastric cancer target cells BGC823 and BSA-TNP. By using special bridge method, only hybrid-hybridomas 6A3 (gamma 2b, mu), and 1G7 (gamma 2b, gamma 2b) were confirmed to secrete bsMAb. Further experiments showed that the bsMAb 6A3 and 1G7 could mediate different cytotoxicities, for example, Ricin-TNP, MMC-HSA-TNP and ADM-BSA-TNP. This system is useful for evaluating different tumoricidal agents in bsMAb targeting therapy, and has potential value in clinics.(ABSTRACT TRUNCATED AT 250 WORDS)

Absence of formation of benzo[a]pyrene/DNA adducts in the cuttlefish (Sepia officinalis, Mollusca: Cephalopoda)

Benzo[a]pyrene (B[a]P) injected intramuscularly into the base of the arms of cuttlefish was released continuously from the injection site and removed from the organism. Only a portion of the compound accumulated in the body. Twenty-four hr after its injection, 75% of B[a]P applied in olive oil was removed from the cuttlefish, and 1.2% was found in the body outside the head, the site of injection. If the carcinogen was dissolved in dimethylformamide, the removal of B[a]P was slower, so that only 18% of the injected B[a]P was removed from the organism and 0.36% accumulated in the body outside the head 24 hr after injection. The high level of B[a]P in gills and hemolymph 4 hr after injection and the kinetics of the decrease of its concentration with time indicate that these two organs could be involved in the excretion of B[a]P from the body. The B[a]P/DNA adducts characteristic for vertebrates could not be demonstrated in gills, skin, brain, hepatopancreas, and lymphocytes of the cuttlefish 24 hr after injection of B[a]P. The dose of the carcinogen injected into the cuttlefish was 2-4 times higher than the dose resulting in the formation of a high level of B[a]P/DNA adducts in the vertebrates. A different metabolism of B[a]P in the tissue of cephalopods, compared to vertebrates, could be less favorable to the process leading to malignant transformation and could explain the absence from the literature of reports of tumors in cephalopods.

Persistence, gestation stage-dependent formation and interrelationship of benzo[a]pyrene-induced DNA adducts in mothers, placentae and fetuses of Erythrocebus patas monkeys

Since DNA adducts have been detected in the placentae of pregnant women who smoke cigarettes, the importance of these adducts as biomarkers of fetal exposure and risk has been evaluated using a non-human primate as a model. Pregnant Erythrocebus patas monkeys on days 50, 100 or 150 of gestation (term = 160 +/- 5 days) were treated once with 5-50 mg/kg benzo[a]pyrene (B[a]P), p.o. Fetuses were removed by Cesarean section 1-50 days after treatment and analyzed for DNA adducts by the nuclease P1 version of the 32P-postlabeling method. B[a]P induced high levels of DNA adducts in all fetal organs, placentae and maternal livers in all three trimesters of gestation. DNA adduct levels were higher in mid-gestation compared to early and late gestation. The major adduct detected was 10 beta-(deoxyguanosin)-N2-yl-7 beta,8 alpha,9 alpha-trihydroxy-7,8,9,10- tetrahydro-B[a]P. The adduct levels in fetal tissues increased with B[a]P dose, but at a much lower rate than in placentae or maternal livers. Preference in binding to DNA of various fetal organs was more apparent in early gestation compared to late gestation and at lower doses compared to higher doses. During early gestation and at low doses, B[a]P produced a similar level of DNA adducts in fetal lung, fetal liver, maternal liver and placenta. Individual fetal organ adduct levels correlated significantly with placental adduct levels, indicating placental and/or maternal contribution to genotoxic injuries in fetuses. However, the slopes of linear regression lines of correlation analyses varied among organs and among gestation stages at treatment, indicating fetal contribution to its own genotoxic injuries. DNA adduct levels in fetal skin were the lowest of all fetal organs tested and less affected by gestational stages at time of treatment. In contrast, DNA adduct levels in fetal liver exhibited distinct gestation stage specificity with higher adduct levels attained during mid-gestation compared to other stages of gestation. Adduct levels decreased at a much faster rate during the first 10-15 days compared to 15-50 days after B[a]P treatment. However, 10% of DNA adducts persisted 50 days after treatment in all organs studied. Together, the results suggest that placental adduction accurately indicates fetal exposure. Toxicokinetics of B[a]P and its metabolites as well as maternal, placental and fetal competence in activation and deactivation of B[a]P may be critical determinants in overall fetal risk to genetic damage. Importantly, maximal sensitivity to transplacental DNA damage may be during mid-gestation.

[Ultrastructural changes in endothelial cells in rabbits with multiple organ failure (MOF)]

The morphological lesions of endothelial cells in rabbits with MOF were studied by scanning (SEM) and transmission electron microscopy (TME). The edges of the cells were blurred in the MOF groups. TEM showed that the nuclei were irregular and the mitochondria were swollen. The results indicated that the vascular endothelial cells were injured in rabbits with MOF in various extent. Administration of vitamin E in the early stage seemed beneficial in protecting the endothelial cell in this event.

Cytotoxic activity of trewiasine in 4 human cancer cell lines and 5 murine tumors

Trewiasine (TWS) is a mytansinoid compound. It possessed a significant cytotoxic activity against various human cancer cell lines in vitro. U937 cells, which were more sensitive to the TWS, required TWS 1 microgram.ml-1 to inhibit cell growth over 90% (P less than 0.01). TWS also showed activities against murine tumors in vivo, such as the ascitic tumors S180, hepatoma, U14, and solid tumor Lewis lung carcinoma. Depression of leukocytes was not seen when mice were given ip TWS 10 or 50 micrograms.kg-1.d-1 x 7 d. TWS 0.1-1 micrograms.ml-1 caused no sister chromatid exchange induction in Chinese hamster cell line V79.

[Clinical application of retrograde island flap from back of the hand]

With the blood vessels filled with dye, 12 fresh specimens of adult human hand were dissected. At web spaces, anastomoses between artereiae palmariae dorsales and arteriae digitalis palmares communes or their branches were always present. The anastomotic branch was 0.4-0.8 mm thick and 11-14 mm long, and was accompanied by 2 veins, lying superficially in the subcutaneous space. With the anastomotic branch as an axis and the arteriae palmares dorsales as pedicle, a retrograde island flap back of the hand was designed and employed to cover skin defect of finger in 11 patients. One of the flaps was transposed together with an extensor tendon. The defect was covered by suturing together the skin edges on both sides and healed nicely. The 11 transpositioned flaps varying from 3.5 x 2.2 cm2 in size were taken successfully. Follow-up examination for 2-10 months after operation revealed fine texture of and good sensation over the flaps, and good function of the transplanted extensor tendon. We conclude that this kind of flap is physiologically sound and easy to be made for the repair of palmar defect and in finger defect.

Detection of 8-hydroxy-2'-deoxyguanosine in deoxyribonucleic acid by the 32P-postlabeling method

Using synthesized 8-hydroxy-2'-deoxyguanosine 3'-monophosphate as a marker, the 32P-postlabeling method was adapted with minimum modifications for the analysis of 8-hydroxy-2'-deoxyguanosine (8-OH-dG) content in deoxyribonucleic acid (DNA). This method allows the analysis of one 8-OH-dG per 10(4) DNA nucleotides with only 10 pmoles of nucleotides required. The amounts of 8-OH-dG in DNA detected by the postlabeling method correlated well with the electrochemical detection method but were consistently lower.