Correction of secondary velopharyngeal insufficiency in cleft palate patients with the Furlow palatoplasty

To avoid the serious complications of pharyngeal flap surgery, a Furlow palatoplasty was used to correct velopharyngeal insufficiency after primary palatoplasty in 18 Chinese cleft palate patients (3 to 23 years old) from 1988 to 1992. The follow-up duration was 1 to 4 years. These patients were selected after a complete study for velopharyngeal insufficiency, including intraoral examination, perceptual speech assessment, videonasopharyngoscopy, and/or multiview videofluoroscopy. The criteria for selection included age, pattern of velopharyngeal closure, size of the velopharyngeal gap, extent of lateral pharyngeal wall movement, existence of a Passavant's ridge, and abnormal levator veli palatini muscle insertion. Complete velopharyngeal closure was achieved for 16 patients after surgery. The majority of these patients (15) had a velopharyngeal gap less than 5 mm. The 2 patients who still had velopharyngeal insufficiency after the surgery had a velopharyngeal gap larger than 10 mm before the surgery. The most important factor seemed to be the size of the velopharyngeal gap. Pattern of velopharyngeal closure or age of the patient also might play an important role. The results showed that a Furlow palatoplasty can satisfactorily correct velopharyngeal insufficiency in carefully selected patients. Although the criteria for the selection of this operation need further study, present results are encouraging.

Assay for prostate specific antigen (PSA): problems and possible solutions

The absolute tissue specificity of prostate specific antigen (PSA) allows the use of PSA test not only for detecting recurrence or metastasis at an early stage after radical prostatectomy but also for screening prostate cancer if combined with digital rectal examination. There is also a need to improve the current PSA test to better differentiate between prostate cancer and benign prostate hyperplasia (BPH). Because of these clinical applications, a much greater demand was placed on PSA test for extra sensitivity, accuracy, and precision even within the normal PSA concentration range. However, the current commercial assay kits for PSA do not provide correct PSA values. Many factors contributing to the problem include the specificity of the anti-PSA antibodies, the composition of the calibrator, the PSA values assigned to the calibrator, the PSA isoform used for anti-PSA antibody preparation, the test design, and the composition of the diluent. Most problems were derived from the failure of realizing earlier that the majority of the PSA exists in serum not as free PSA but as complexes with protease inhibitors. Other problems, such as constantly changing composition of various forms of PSA in serum specimens, and different clearance rates for various forms of PSA make almost impossible to develop an ideal assay for PSA. Therefore, we suggest that test should be designed for measuring PSA-ACT (PSA-alpha 1-antichymotrypsin) complex only. Changing the focus from the measurement of total PSA of various forms to the PSA-ACT complex alone may improve the differentiation between prostate cancer and BPH but may also simplify the selection of anti-PSA antibodies and the preparation of calibrator for the assay.

Comparison of neural network and k-NN classification methods in medical image and voice recognitions

We make a comparison of classification ability between BPN (Back Propagation Neural Network) and k-NN (k-Nearest Neighbor) classification methods. Voice data and patellar subluxation images are used. The result was that the average recognition rate of BPN was 9.2 percent higher than that of the k-NN classification method. Although k-NN classification is simple in theory, classification time was fairly long. Therefore, it seems that real time recognition is difficult. On the other hand, the BPN method is long in learning time but is very short in recognition time. Especially if the number of dimensions of the samples is large, it can be said that BPN is better than k-NN in classification ability.

Identification and characterization of microcystin-LY from Microcystis aeruginosa (strain 298)

Two toxins, a main component A and a minor component B, were isolated from the freshwater cyanobacterium Microcystis aeruginosa (strain 298) and characterized in their chemical structure by amino-acid analysis, configurational analysis, by FAB-MS and 1H-NMR spectroscopy. The acid hydrolysate yielded for toxin A as constituent amino acids D-Ala, L-Leu, D-Glu, erythro-D-beta-Me-Asp and L-Arg, and for toxin B the amino acids D-Ala, L-Leu, D-Glu, erythro-D-beta-Me-Asp and L-Tyr. 1D and 2D 1H-NMR spectroscopy of the toxins A and B in DMSO-d6 allowed to characterize them as cyclic heptapeptides containing both the unusual beta-amino acid Adda (3-amino-9-methoxy-2,6,8-trimethyl-10-phenyldeca-4,6-dienoic acid) and N-methyldehydroalanine (Mdha) as additional constituent residues. Toxin A was found to correspond to the known and structurally well characterized microcystin-LR and toxin B to microsystin-LY. The presence of this variant has already been proposed, but its primary structure could be confirmed in this study.

[Alternative combination chemotherapy with mitomycin C, vincristine, methotrexate, 5-fluorouracil, cis-platinum and adriamycin for adenocarcinoma of the lung]

Efficacy of an alternative combination chemotherapy with MMC, VCR, MTX, 5-FU, CDDP and ADM for adenocarcinoma of the lung is reported. Forty-one advanced cases (stage III: 9; IV: 32) were chosen for the chemotherapy. Two combination chemotherapies MMC + VCR + MTX + 5-FU + CDDP: MVMFP; MMC + VCR + MTX + 5-FU + ADM: MVMFA were repeated alternatively for 8 consecutive weeks with 2 interposed rest weeks, and this regimen was completed in 34 cases. All 41 cases were evaluable. Three and 26 cases achieved complete and partial responses, respectively. The response rate was 70.7%, and the median survival time was 13 months. The adverse effects of the chemotherapy observed were tolerable: alopecia (63.4%), gastrointestinal symptoms (14.5%), bone marrow toxicity (12.2%) and liver dysfunction (4.8%). These results indicate that our MVMFP/MVMFA alternative chemotherapy is quite effective for adenocarcinoma of the lung, comparable or superior to conventional chemotherapies.

Advanced glycosylation end products: a new disease marker for diabetes and aging

Advanced glycosylation end products (AGEs) are a potentially useful marker for monitoring glycemic control, predicting the risk of diabetes- and aging-associated clinical complications, and monitoring the treatment of patients with micro- and macrovascular diseases, including retinopathy, atherosclerosis, nephropathy, and neuropathy. AGEs or AGE-proteins are derived from nonenzymatically glycated proteins (Amadori products) after further cross-linking with other proteins and additional rearrangement. AGE-proteins can be assayed by either radioreceptor or immunoassays in blood and tissues. No commercial kit is available at this time.

Detection of the extracellular domain of c-erbB-2 oncoprotein in sera from patients with various carcinomas: correlation with tumor markers

Using a serum enzyme immunoassay (EIA) kit from Triton diagnostics we detected c-erbB-2 oncoprotein activity in random sera containing highly elevated tumor markers and also in serial specimens from cancer patients expressing elevated oncoprotein activities. Elevated oncoprotein activity was found not only in sera of breast and ovarian carcinomas but also in sera from colorectal, pancreatic, and prostate carcinomas and even from primary hepatoma. Whenever oncoprotein was overexpressed in an individual patient, there was usually an excellent correlation between the oncoprotein activity and the level of dominant tumor marker in serial serum specimens. Based on the size exclusion S-200 column chromatography, we found only a single molecule containing c-erbB-2 oncoprotein activity in pooled sera from cancer patients whereas two oncoproteins slightly different in size were detected in breast tumor tissue cytosol. Using HPLC on a Superose 12 HR column, the serum portion of the oncoprotein was eluted at a position near IgG, suggesting that the extracellular domain of the oncoprotein exists as a dimer in the serum.

Development of radioimmunoassays on microplate: application for CA-GI and CA-Br tumor markers

By taking advantage of a newly available microplate counter for radioactivity and the organic solvent-resistant, pigmented microplates, we have successfully established radioimmunoassays (RIA) for both CA-GI and CA-BR on microplate for routine clinical use. In the process of assay development, we found that both pigmented PicoPlate, made of acrylonitrile, and polystyrene Microlite 2 can be coated with antialpha fetoprotein (AFP) and antinerve growth factor (NGF) and used for setting up immunoassays for AFP and nerve growth factors. There were no problems following a test format of either competitive binding or sandwich design. Microlites 2 is recommended over PicoPlate because Microlites 2 is made of polystyrene, which is less expensive and separable into 8-well strips or even single wells. Single-well separation allows for the use of regular gamma counters in case Topcount is unavailable. We also found that the sensitivity of these tests was not significantly affected even though Topcount counts the weaker beta emissions. Similar dose-response curves could also be generated between original Biomira tube assays and assays using PicoPlate or Microlite 2 coated with protein antigens CA-Br and CA-GI. Excellent correlations were also obtained between the microplate assays and the Biomira tube assays for CA-GI and CA-Br using groups of serum specimens from cancer patients. We recommend the development of various RIAs on the microplate: it requires less reagents and less sample handling by the technologists and it can be essentially automated.

Review of diabetes: identification of markers for early detection, glycemic control, and monitoring clinical complications

The hallmark of diabetes mellitus, whether type I or type II, is hyperglycemia. Clinical complications associated with diabetes are most likely the consequence of hyperglycemia via both altered metabolic pathways and nonenzymatic glycation of proteins. The nonenzymatic glycation of proteins is accelerated in diabetes due to elevated blood glucose concentration. The Amadori product of nonenzymatic glycation will further cross-link with other proteins to form advanced glycosylation end products (AGEs). The reaction of AGEs with long-lived proteins, such as collagen, and the uptake of AGEs by the receptors on macrophages, endothelial cells, and platelets are major reasons for the development of various clinical complications in diabetes. Several markers have been identified for the screening, diagnosis, and monitoring of the disease. Autoantibodies against beta cells are the best markers for mass screening and for early detection of type I diabetes. In addition to glycated hemoglobin, AGEs and blood glycated proteins of various half-lives could be used for monitoring glycemic control. Several abnormal metabolites have been identified as potential markers for monitoring the severity of various clinical complications. The most interesting findings in diabetic markers could be AGEs. The amount of AGEs found in the tissues could be related to the extent of micro- and macrovascular damage and might prove useful for monitoring the treatment of patients at early stages of either nephropathy, atherosclerosis, retinopathy, or neuropathy.

Rhabdomyosarcoma cell line can be used for the isolation of soluble acetylcholine receptor and for assaying blocking and modulating autoantibodies

We found that the Rhabdomyosarcoma (RD) cell line expresses human acetylcholine receptor (AChR) based on the following evidences: 1. Soluble AChR can be isolated from RD cells following the isolation procedure for AChR from human muscle; 2. Intact RD cells bind to alpha-bungarotoxin (alpha Butx) in a time-dependent and saturable fashion. The apparent dissociation constant (5.3 x 10(-10) M) is very similar to that reported for TE671 cells, which is known to express AChR; 3. Like fresh muscle culture, RD cells not only bind but also internalize 125I-alpha Butx. Soluble AChR from RD cells can be labeled specifically with 125I-alpha Butx and then used to quantify binding autoantibodies in myasthenic patients. We also demonstrate that blocking antibodies can be detected in sera from patients with myasthenia gravis (MG) using RD cells and the ability of RD cells to internalize alpha Butx. Consequently, RD cells can be used as a reliable source for obtaining soluble AChR and as a replacement for rodent or human muscle cultures in measuring blocking and modulating antibodies.

The long-term modality effect: in search of differences in processing logographs and alphabetic words

The visual superiority effect (a reverse long-term modality effect) has been consistently found with Chinese logographs. For its explanation in terms of script differences, it has been believed that lexical access is more direct or quicker for Chinese logographs than for alphabetic words. It has also been believed that Chinese logographs are more unique in shape or more discriminable than alphabetic words. Finally, Chinese logographs have been considered to facilitate recall through their graphic features that classify Chinese words into categories. The results of Experiments 1-5 show that these three assumptions can be ruled out. The results of Experiments 6-10, on the other hand, support the long-term priming interpretation of the visual superiority effect, which explains (a) why the visual superiority effect can be consistently obtained for recall of Chinese words by Chinese subjects, (b) why the effect cannot be consistently obtained for recall of English words by Western subjects, (c) why the effect can be also obtained for recall of English words by Chinese subjects, (d) why the effect can be easily obtained for recall of a set of words, but not for recall of a different set of words by Chinese subjects, and (e) why the effect can be easily obtained from Chinese subjects speaking a dialect that is different from Mandarin.

Chromatographic characterization of CA 19-9 molecules from cystic fibrosis and pancreatic carcinoma

We have compared the size, the binding to Concanavalin A (Con A), and the affinity for monoclonal antibody 1116NS-199 (Mab 19-9) among CA 19-9 molecules from sera of cystic fibrosis (CF) and pancreatic carcinoma patients and from sputum extracts. CA 19-9 molecules of two different sizes were found in all types of specimens by Sepharose 4B chromatography. While the smaller CA 19-9 molecule was predominant in CF patient sera, the larger molecule was associated with most of the sera from patients with pancreatic carcinoma. The majority of the sputum extracts contained the larger CA 19-9 molecule. All CA 19-9 molecules studied by Con A chromatography did not appear to bind to Con A, and almost 100% were found in the nonreactive fraction. The CA 19-9 molecules from sera of either CF or pancreatic carcinoma patients exhibited variable affinities for Mab 19-9, some approaching that of the standard curve but many also having lower affinities. The lowest affinity was displayed by CA 19-9 molecules from the sputum extract. It appears that development of more specific assays for CF and for carcinoma is possible if the correct CA 19-9 molecule is selected for antibody preparation and for use as standards.

Low frequency and low level of elevation of serum CA 72-4 in human carcinomas in comparison with established tumor markers

We evaluated a new circulating tumor marker, CA 72-4, by comparing its frequency of appearance and level of elevation with other established tumor markers in serial serum specimens from patients with various carcinomas. We found that CA 72-4, though highly expressed and widely found in various tumor tissues, is present at low concentration and frequency in the serum. In breast, colon, ovarian, and pancreatic carcinomas, only 21%, 30.9%, 16%, and 26.5% of specimens, respectively, showed elevated CA 72-4. When elevated, the level of elevation was also low, much lower than that of the dominant markers. Poor response of CA 72-4 to therapy was especially noticeable in serial specimens. In most cases, the CA 72-4 remained normal for the entire series while other markers remained at elevated levels. However, changes of the level of CA 72-4 usually paralleled those of other markers but at a much lower concentration. Simultaneous measurement of CA 72-4 and CA 19-9 appears useful to differentiate colorectal from pancreatic carcinomas when they all contained elevated levels of CA 19-9. There was a much higher ratio of CA 72-4 to CA 19-9 with colon than with pancreatic and other carcinomas (247 +/- 524 vs. 4.7 +/- 6.8).

Conversion of a qualitative screening test to a quantitative measurement of urinary cystine and homocystine

Qualitative urinary screening procedures were converted to quantitative methods for urinary cystine and homocystine based on the reactions between these amino acids and cyanide-nitroprusside reagents. Cystine and homocystine are quantified by the measurement of absorbances at 521 and 524 nm, respectively. Cyanide-nitroprusside reacts with both cystine and homocystine. However, in the presence of silver nitrate, only homocystine reacts to produce a magenta color. Following the cyanide-nitroprusside reaction, absorbance must be read within three minutes for cystine and immediately for homocystine. The stability of the absorption spectra has no apparent effect on these quantitative assays. Amino acid concentrations are expressed as ratios to creatinine, which tends to eliminate false negative results in dilute urine specimens. The normal urine value for cystine and homocystine combined is 66.8 +/- 52 (n = 50) mg per g creatinine. The normal value for homocystine alone is 29.9 +/- 16.8 (n = 24) mg per g creatinine. The simplicity of these procedures allows these quantitative methods to be used as screening tests for cystinuria and homocystinuria.

Tumor markers CA 19-9 and CA 195 are also useful as markers for cystic fibrosis

When monoclonal kits are used we can no longer detect highly elevated serum concentrations of carcinoembryonic antigen in cystic fibrosis (CF) patients as we could earlier (Pediatr Res 10:223-236, 1975). Instead, we find increased concentrations of CA 19-9 or CA 195 in the CF sera. The serum levels of CA 19-9 not only reflect the pulmonary condition of CF patients but also respond well to antibiotic therapy. Several lines of evidence suggest that the elevated serum concentration of CA 19-9 is derived from sputum and corresponds with the amount of sputum in the lung. Correlations between CA 19-9 and CA 195 in random and serial specimens from both patients with CF and patients with pancreatic carcinoma suggest that all sera contain heterogeneous, Lewis blood group-related epitopes and the proportions of various epitopes are different among individual patients. When monitored on multiple tumor markers, the pattern of CF is different from that of pancreatic carcinoma although both usually show elevated CA 19-9. Our study indicates that both CA 19-9 and CA 195 can be used as sensitive markers for the early detection of exacerbation in CF patients.

Variation of geosmin content in Anabaena cells and its relation to nitrogen utilization

The addition of the proper amount of ammonium to the culture medium containing nitrate as nitrogen source enhanced the growth rate of Anabaena viguieri. The amount of geosmin produced by these cells varied with the concentrations of ammonium added. A negative correlation between the amount of geosmin produced and of the growth rate of cells was revealed. This was also found in cells grown on various forms of nitrogen sources. Without supply of any nitrogen compound, this organism is capable of fixing gaseous nitrogen, and under these conditions the cells grew relatively slowly. However, they produced more geosmin (per unit protein mass) than cells grown in the presence of combined nitrogen. The isolation of heterocysts, in which nitrogen was fixed, showed that these cells produced higher amounts of geosmin than vegetative cells. The possible relation of nitrogen assimilation to the production of geosmin in the cells was discussed.

Ca(2+)-insensitive modulation of a K+ conductance by inositol polyphosphates

Macrophages derived from phorbol ester-induced human leukemic (HL-60) cells exhibit a voltage-activated inward rectifying potassium conductance which was modulated by macrophage colony-stimulating factor (Wieland, S. J., Chou, R. H., and Gong, Q. H. (1990) J. Cell. Physiol. 142, 643-651). Roles of intracellular messengers in this regulatory mechanism were investigated. Intracellular dialysis with inositol 1,3,4,5-tetrakisphosphate (IP4) or inositol 1,4,5-trisphosphate during tight-seal whole cell recording produced a rapid increase in the inward rectifying conductance. Changes in intracellular Ca2+ levels alone did not reproduce the stimulatory effect of these modulators. Intracellular dialysis with guanosine 5'-O-(thiotriphosphate) (GTP gamma S) resulted in profound inhibition of this conductance. These data suggest a novel cellular function for inositol polyphosphates, particularly IP4, and show antagonistic modulation with GTP gamma S on a human macrophage inward rectifier.

Screening for inborn errors of amino acid metabolism

Early diagnosis and treatment may prevent brain damage and mental retardation in young infants with inborn errors of amino acid metabolism. The abnormal blood and urinary amino acids and their metabolites are listed in two separate tables in association with each disorder to aid laboratories in making a diagnosis during screening. Because of recent developments and discoveries, more detailed descriptions and diagnostic approaches in phenylketonuria (PKU) variants and urea cycle deficiencies are also presented. The test procedures routinely used for screening inherited metabolic disorders are also described. These include five simple chemical tests to detect excessive metabolites and amino acids; a one dimensional thin layer chromatography (TLC) to screen urine for abnormal amino acid patterns; a two-dimensional TLC for semiquantitative identification of amino acids in both urine and blood; and a high performance liquid chromatographic (HPLC) method for quantitative identification of amino acids. In addition, both one- and two-dimensional chromatographies run on small thin layer cellulose plates, are introduced, modifications which save a great deal of time, labor, and reagents. A new automated HPLC system is introduced for the quantitation of both primary and secondary amino acids; the sensitivity and speed of this system is especially useful for screening large numbers of physiological fluids. It is recommended that both the urine and blood from the same patients be screened to ensure that a diagnosis is not overlooked.

Acetylcholine receptors from normal human muscle: concentration, purification, and use in radioreceptor assays for autoantibodies

We measured the concentration of acetylcholine receptor (AChR) in various normal human muscles, obtained at autopsy, in order to find a more reliable and convenient source than the amputated leg muscle from diabetic patients for the isolation of AChR. We found that human calf muscle contains the highest concentration of AChR, approaching the concentration of receptor required for the radioreceptor assay for autoantibodies in myasthenia gravis (MG). Because the amount of contaminant proteins in the receptor preparations affect the sensitivity and precision of the assay, various chromatographic techniques were tested to improve the purity of the receptor preparation. We found that both G-100 Sephadex and DEAE Sephacel chromatographies were effective in removing contaminant proteins. DEAE Sephacel chromatography is particularly useful because the procedure provides higher recovery of receptor. Against the same pool of autoantibodies from patients with MG, AChRs from diabetic and normal leg muscle exhibit similar affinities. We conclude that AChR from normal human calf muscle can be used in radioreceptor assays for measuring autoantibodies in patients with myasthenia gravis.

Effect of different test designs of immunoassays on "hook effect" of CA 19-9 measurement

Determining serum CA 19-9 using regular Centocor kit frequently requires numerous repeats when specimens contain highly elevated levels of CA 19-9. We found that the number of repeats could be reduced if the Centocor kit with an extended concentration range was used. Using an extended Centocor kit could also eliminate falsely low CA 19-9 results. However, when a Biomira RIA kit, based on a competitive binding principle, was used, falsely low CA 19-9 values could be completely avoided and, in most cases, only a single repeat was usually required to arrive at the true result. This is because the level of CA 19-9 in the specimen can be approximated from the radioactivity count. Therefore, when designing an immunoassay for tumor markers, one needs to take into consideration the concentration range of the tumor marker in the specimens if one would like to avoid repeats and falsely low values.

Internal consistency and factor structure of the Chinese Health Questionnaire

The internal consistency and factor structure of the Chinese Health Questionnaire (CHQ) were investigated in 2 samples in Taiwan, one from 3 communities (n = 1023) and the other from consecutive attenders for health screening in a general hospital (n = 386). Cronbach's alpha coefficients were calculated to be 0.84 and 0.83 for the 12-item and 0.90 and 0.92 for the 30-item CHQ version. Four factors similarly extracted for the CHQ-30 in both samples include somatic symptoms, anxiety and worrying, social dysfunction, and depression and poor family relationship. The implications of these findings were discussed from a cross-cultural perspective.

RU 486 interferes with egg transport and retards the in vivo and in vitro development of mouse embryos

Oral administration of RU 486 at 100 mg/kg BW/day to mice on Days 1 and 2 of pregnancy caused retention of embryos in the oviduct and expulsion of those having entered the uterus. The treatment also retarded the development of embryos. In vitro study showed that RU 486 reduced the percentage of 2-cell mouse embryos developing into blastocysts. Thus, in addition to interfering with egg transport and impairing embryonic development in vivo, RU 486 can act directly on the embryo, interfering with preimplantation development in vitro.

Serum alpha-fetoprotein and its lectin reactivity in liver diseases: a review

Increased serum concentration of alpha-fetoprotein (AFP) can be found in benign and malignant liver diseases, in yolk sac tumors, and in several nonhepatic neoplasms at advanced stage. The frequency and level of elevated serum AFP are highest in hepatocellular carcinoma (HCC) and yolk sac tumors. Most levels of serum AFP in HCC are greater than 500 ng per mL, whereas the serum AFP in most of the benign liver diseases is only moderately elevated and is transient in nature. Determination of lectin reactivity of serum AFP is helpful for the differentiation of HCC from other diseases associated with elevated serum AFP. Determination of Len culinaris agglutinin (LCA) reactivity of serum AFP is useful for the differentiation of HCC from benign liver diseases, and for early detection of hepatoma. Determination of concanavalin A (Con A) nonreactive AFP variant is useful for the differentiation of HCC from yolk sac tumors and may also allow for the differentiation of HCC from nonhepatic neoplasms. However, reaction with several lectins may be required if differentiation among various nonhepatic neoplasms is needed.

Conversion of pregnenolone to progesterone by mouse morulae and blastocysts

When mouse morulae, early blastocysts and implanting blastocysts were cultured with tritiated pregnenolone, tritiated progesterone and its metabolites, 5 alpha-pregnan-3,20-dione and 3 alpha-hydroxy-5 alpha-pregnan-20-one, were isolated from the medium. It appears that mouse embryos can make progesterone from pregnenolone and the progesterone is quickly metabolized into various metabolites. These abilities increase with development. It is suggested that the mouse embryo can make progesterone and may regulate its own progesterone level for optimal development.

Metabolism of estrogens by rabbit blastocysts: formation of estrogen glucosides and preferential conversion of estrone to estradiol-17 beta

When day 6 rabbit blastocysts were cultured (3 embryos/mL) in medium 199 containing 3.68 microM estradiol-17 beta (E2), 40% of E2 was metabolized in 24 h, at a rate of 18 pmol/embryo(b)/h, yielding 4 major metabolite fractions. Two of them were identified to be estrogen glucosides: 17 beta-hydroxyestra-1,3,5(10)-trien-3-yl beta-D-glucopyranoside (E(2)3G) (12 pmol/b/h) and 17-oxoestra-1,3,5(10)-trien-3-yl beta-D-glucopyranoside (E(1)3G) (0.5 pmol/b/h). If the blastocysts were cultured in 3.68 microM E1 medium, 75% of E1 was metabolized in 24 h (34.1 pmol/b/h); most of it appears as E2 (8 pmol/b/h), E(1)3G (16 pmol/b/h), and E(2)3G (6 pmol/b/h). Thus, the 17 beta-hydroxysteroid dehydrogenase activity in the rabbit blastocysts catalyzes mainly in the direction of the E1----E2 conversion, with little or no E2----E1. This may be responsible in part for the faster metabolism of E1 than E2 by the rabbit blastocyst. In comparison with the rat, mouse, and hamster blastocyst, the rabbit embryo shows an additional capability to conjugate large amounts of estrogens into glucosides by steroid glucosyltransferase.