An Assay for HIV RNA in Infected Cell Lysates, and its use for the Rapid Evaluation of Antiviral Efficacy

A rapid, high-capacity assay for evaluating the potency of anti-HIV compounds was devised. This assay measures cell associated viral RNA levels 3 days after infection of susceptible T-cell lines grown in individual microtitre plate wells. Viral RNA was quantified by a sandwich hybridization assay, the first step of which was performed directly in crude infected cell lysates prepared in guanidinium isothio-cyanate. Levels of cell-associated viral RNA were shown to correlate with the yield of infectious virus and this correlation formed the basis of the test. Antiviral potencies of a large series of compounds tested in this RNA hybridization assay correlated closely with potency values determined by a sensitive but slower and more labour-intensive yield-reduction assay. Both laboratory strains and selected clinical isolates of HIV can be detected in this RNA hybridization assay.

Compositional Changes in Compost during Composting and Growth of Agaricus bisporus

Samples from conventional compost taken at various stages of composting and mushroom (Agaricus bisporus) growth were analyzed for changes in 80% ethanol and water extracts, monosaccharides in acid hydrolysates of polysaccharides, lignin concentration, and lignin structural features. Variable amounts of extraneous inorganic solids in the form of fine sandy particles were removed by sedimentation of the samples in a carbon tetrachloride-dibromomethane mixture. During composting, about two-thirds of the initial wall polysaccharides were consumed by compost microorganisms, and only 17% of the total polysaccharides were used during mushroom production. The relative lignin content of composts as measured by the acetyl bromide procedure increased, both during composting and mushroom growth, and the chemical structure of lignin was altered by condensation and oxidation reactions.

Results of a phase I trial administering Zyflamend to subjects with high-grade prostatic intraepithelial neoplasia

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Background: Subjects diagnosed with prostatic intraepithelial neoplasia (PIN) at prostate biopsy are at increased risk of developing prostate cancer on later biopsies. We initiated a phase I clinical trial to asses the safety and efficacy of the novel herbal anti-inflammatory, Zyflamend, to prevent prostate cancer in high-risk subjects with PIN. Methods: Men ages 40–75 diagnosed with high-grade PIN (without prostate cancer) on biopsy within the last six months were enrolled. Patients were assigned to one of eight treatment groups, with successive dose-escalation occurring in each group. Patients were evaluated every three months for 18 months; at which time they had a physical exam and blood samples drawn to monitor for toxicity, to check for fluctuations in PSA and testosterone, and monitor a battery of inflammatory serum. At 6, 12 and 18 months, 12-core transrectal ultrasound guided biopsy of the prostate was performed. Biopsy tissue was evaluated for the presence of PIN and/or prostate cancer then stained for inflammatory biomarkers. A NCI common terminology criteria for adverse events (v3.0) based questionnaire was used to monitor side effects. Endpoints are completion of the 18 month protocol without adenocarcinoma or diagnosis of adenocarcinoma prior to 18 months. Results: To date 25 patients have been enrolled; the expected closure date is March, 2006. The median patient age is 65.1 years with a median PSA level of 6.8. There have been no adverse events reported or toxicities apparent. Five patients (20%) have complained of grade I dyspepsia resolving spontaneously without intervention. Preliminary results include a total of 22 biopsies performed in 19 patients. 18 of the 22 biopsies were performed per protocol at scheduled visits, the remaining four were performed between scheduled visits. Of 22 biopsies completed seven returned positive for PIN (31.8%) and three have returned with adenocarcinoma (13.6%). Conclusions: The novel herbal anti-inflammatory, Zyflamend, appears to be associated with minimal toxicity and no serious adverse events when administered orally. Short term biopsy results indicate a low progression rate, although long-term efficacy awaits further studies.

No significant financial relationships to disclose.

Curdlan and other bacterial (1→3)-β-d-glucans

Three structural classes of (1-->3)-beta-D-glucans are encountered in some important soil-dwelling, plant-associated or human pathogenic bacteria. Linear (1-->3)-beta-glucans and side-chain-branched (1-->3,1-->2)-beta-glucans are major constituents of capsular materials, with roles in bacterial aggregation, virulence and carbohydrate storage. Cyclic (1-->3,1-->6)-beta-glucans are predominantly periplasmic, serving in osmotic adaptation. Curdlan, the linear (1-->3)-beta-glucan from Agrobacterium, has unique rheological and thermal gelling properties, with applications in the food industry and other sectors. This review includes information on the structure, properties and molecular genetics of the bacterial (1-->3)-beta-glucans, together with an overview of the physiology and biotechnology of curdlan production and applications of this biopolymer and its derivatives.

A (1-->4)-beta-mannan-specific monoclonal antibody and its use in the immunocytochemical location of galactomannans

Galactomannan was coupled to a protein carrier for the preparation of monoclonal antibodies. The monoclonal antibodies generated bound to galactomannans from different sources as well as to glucomannan and galactoglucomannan. One monoclonal antibody, BGM C6, was characterised and found to be specific for (1-->4)-beta-linked mannopyranosyl residues; it had a binding affinity estimated at 1x10(-6) M for the (1-->4)-beta-linked mannohexaose. BGM C6 was used in immunogold labelling studies to locate galactomannans in the endosperm walls of normal coconuts (Cocos nucifera L.) and those of the mutant makapuno at two different developmental stages. The pattern and intensity of antibody labelling varied for each type of coconut at the mature and immature stages, indicating differences in the galactomannan composition of the endosperm walls.

Structure of epiglucan, a highly side-chain/branched (1 --> 3;1 --> 6)-beta-glucan from the micro fungus Epicoccum nigrum Ehrenb. ex Schlecht

The extracellular fungal polysaccharide, epiglucan, synthesised by Epicoccum nigrum is a side-chain/branched (1 --> 3;1 --> 6)-D-beta-glucan. Methylation analysis, 13C DEPT NMR and specific enzymic digestion data show slight variation in branching frequency among the epiglucans from the three strains examined. The (1 --> 3)-beta-linked backbone has (1 --> 6)-beta-linked branches at frequencies greater than the homologous glucans, scleroglucan and schizophyllan, from Sclerotium spp. and Schizophyllum commune, respectively. The structural analyses do not allow a distinction to be made between structures I and II. [structures: see text] Epiglucan displays non-Newtonian shear thinning rheological properties, typical of these glucans.

Determinants of the outcome of intrauterine insemination: analysis of outcomes of 9963 consecutive cycles

OBJECTIVE

Our aim was to determine which factors influence the effectiveness of intrauterine insemination.

STUDY DESIGN

This article is a retrospective statistical analysis of outcomes of 9963 consecutive intrauterine insemination cycles.

RESULTS

Patient age was the main determinant of pregnancy outcome (analysis of variance F ratio = 29, P <.0001), followed by the number of follicles at the time of intrauterine insemination (analysis of variance F ratio = 9, P <.0001) and sperm motility in the inseminate (analysis of variance F ratio = 4, P =.002). A total of 18.9% of all patients <26 years old conceived, compared with 13.9% of those 26-30 years old, 12.4% of those 31-35 years old, 11.1% of those 36-40 years old, 4.7% of those 41-45 years old, and 0.5% of patients >45 years old (P <.001). When analyzed by single years, ongoing pregnancy rates after intrauterine insemination remained high through age 32 years. Across all ages and causes of infertility, 7.6% of patients with 1 follicle at the time of intrauterine insemination conceived, compared with 10. 1% with 2, 14.0% with 4, and 16.9% with 6 follicles (P <.01). When ovulation occurred before intrauterine insemination (ie, no visible follicular structures), 4.6% of patients conceived. The likelihood of pregnancy was maximized when motile sperm numbers were >/=4 million and sperm motility was >/=60%. Differences in pregnancy outcomes between sperm processing options were related to differences in sperm motility after processing; use of methods incorporating motility enhancement with pentoxifylline and motile sperm concentration through silica gradients yielded the highest overall pregnancy rates.

CONCLUSION

When the results of ongoing retrospective analysis of intrauterine insemination outcomes are applied, overall intrauterine insemination pregnancy rates have increased from 5.8% per cycle in 1991 to 13.4% per cycle in 1996, during which time the average age of patients undergoing intrauterine insemination has increased from 36.1 (+/-0.2) to 39.2 (+/-0.1) years.

The influence of gender on incidence and outcome of patients with bladder cancer in Harlem

Although African Americans have a lower incidence of bladder cancer, overall survival is worse compared with American whites. This phenomenon has been attributed to the higher incidence of advanced disease at diagnosis and poor follow-up. Fifty-nine cases of bladder cancer were identified through the Tumor Registry at Harlem Hospital and reviewed retrospectively. Complete data were obtained for 42 patients. The primary independent variables of interest were primary care utilization, comorbid conditions, social variables, and gender. The outcome variables of interest were stage of disease at presentation and death. The median age at diagnosis in this group was 73 years compared with 68 for bladder cancer patients in the United States. There was no statistically significant correlation between primary care utilization or severity of comorbidities, and clinical stage at presentation. Similarly, these variables did not influence the occurrence of death as an outcome. For women, the mean age at diagnosis was 74.2 years compared with 67.3 in men (P = .112). The ratio of male-to-female cases in this group was 1.3 to 1 compared with 2.7 to 1 for the general US population. Women had lower odds of being diagnosed with superficial disease (OR = 0.24, 95% CI, 0.06-0.94) and a higher incidence of a cancer-specific death (OR = 2.7, 95% CI). The poor outcome and high incidence of bladder cancer cases among women in Harlem is intriguing. Overall, primary care utilization, comorbidities, and other social factors did not seem to influence stage or death as an outcome. The significantly elevated prevalence of smoking among women in this community, increased age at diagnosis, and possible environmental influences may play a role.

Field stimulation of isolated chick heart cells: comparison of experimental and theoretical activation thresholds

INTRODUCTION

This study examines the accuracy of using membrane models to predict activation thresholds for chick heart cells during field stimulation.

METHODS AND RESULTS

Activation thresholds were measured experimentally in ten embryonic chick heart cells at 37 degrees C for stimulus durations 0.2 to 40 msec. Activation was assessed by observing the mechanical twitch of the cell. The heart cells ranged in diameter from 15.0 to 26.7 microm. Since the electric field required for activation depends on diameter, the thresholds were expressed as the maximum field-induced transmembrane potential, Vth = 1.5 a Eth, where a is the cell radius and Eth is the strength of the electric field at threshold. A cell model was created using a singular perturbation method and membrane models describing the ionic currents of a heart cell. The study used membrane models of Ebihara and Johnson (1980), Luo and Rudy (1991), Shrier and Clay (1994), and their combinations. The results show that for stimuli longer than 1 msec, theoretical activation thresholds were within one standard deviation of experimental thresholds. For shorter stimuli, the models failed to predict thresholds because of a premature deactivation of the sodium current. The modification of the m gates dynamics, so that they closed with a time constant of 1.4 msec, allowed to predict thresholds for all durations. The root mean square error between experimental and theoretical thresholds was 6.14%.

CONCLUSIONS

The existing membrane models can predict thresholds for field stimulation only for stimuli longer than 1 msec. For shorter stimuli, the models need a more accurate representation of the sodium tail current.

Detection of two loci involved in (1-->3)-beta-glucan (curdlan) biosynthesis by Agrobacterium sp. ATCC31749, and comparative sequence analysis of the putative curdlan synthase gene

Genes essential for the production of a linear, bacterial (1-->3)-beta-glucan, curdlan, have been cloned for the first time from Agrobacterium sp. ATCC31749. The genes occurred in two, nonoverlapping, genomic fragments that complemented different sets of curdlan( crd )-deficient transposon-insertion mutations. These were detected as colonies that failed to stain with aniline blue, a (1-->3)-beta-glucan specific dye. One fragment carried a biosynthetic gene cluster (locus I) containing the putative curdlan synthase gene, crdS, and at least two other crd genes. The second fragment may contain only a single crd gene (locus II). Determination of the DNA sequence adjacent to several locus I mutations revealed homology to known sequences only in the cases of crdS mutations. Complete sequencing of the 1623 bp crdS gene revealed highest similarities between the predicted CrdS protein (540 amino acids) and glycosyl transferases with repetitive action patterns. These include bacterial cellulose synthases (and their homologs), which form (1-->4)-beta-glucans. No similarity was detected with putative (1-->3)-beta-glucan synthases from yeasts and filamentous fungi. Whatever the determinants of the linkage specificity of these beta-glucan synthases might be, these results raise the possibility that (1-->3)-beta-glucans and (1-->4)-beta-glucans are formed by related catalytic polypeptides.

Cell wall (1-->3)- and (1-->3, 1-->4)-beta-glucans during early grain development in rice (Oryza sativa L.)

Immunogold labeling was used to study the distribution of (1-->3)-beta-glucans and (1-->3, 1-->4)-beta-glucans in the rice grain during cellularization of the endosperm. At approximately 3-5 d after pollination the syncytial endosperm is converted into a cellular tissue by three developmentally distinct types of wall. The initial free-growing anticlinal walls, which compartmentalize the syncytium into open-ended alveoli, are formed in the absence of mitosis and phragmoplasts. This stage is followed by unidirectional (centripetal) growth of the anticlinal walls mediated by adventitious phragmoplasts that form between adjacent interphase nuclei. Finally, the periclinal walls that divide the alveoli are formed in association with centripetally expanding interzonal phragmoplasts following karyokinesis. The second and third types of wall are formed alternately until the endosperm is cellular throughout. All three types of wall that cellularize the endosperm contain (1-->3)-beta-glucans but not (1-->3, 1-->4)-beta-glucans, whereas cell walls in the surrounding maternal tissues contain considerable amounts of (1-->3, 1-->4)-beta-glucans with (1-->3)-beta-glucans present only around plasmodesmata. The callosic endosperm walls remain thin and cell plate-like throughout the cellularization process, appearing to exhibit a prolonged juvenile state.

Specificity of binding of beta-glucoside activators of ryegrass (1-->3)-beta-glucan synthase and the synthesis of some potential photoaffinity activators

Structure-activity relationships among glycoside activators of ryegrass (Lolium multiflorum) (1-->3)-beta-glucan synthase were investigated using a number of natural and synthetic glycosides, including some carrying photoaffinity functions. There is an absolute requirement for a beta-D-glycosyl moiety in the activator, both S- and N-glucosides are active, and the position of the glucosidic linkage in beta-glucose disaccharides has a significant effect on the affinity of binding. However, the binding requirement does not extend beyond a single beta-D-glucosyl residue, and beta-D-oligoglucosides are less effective than disaccharides. The nature of the aglycon has a major influence on the binding affinity. Hydrophobic aglycons lower the concentration required for half-maximal stimulation of the enzyme obtained from an Eadie-Hofstee plot of kinetic data (Ka) for activation, but charge aglycons increase Ka. Relative to methyl-beta-D-glucoside and cellobiose (Ka 1.1 mM), the most potent compounds tested were N-[4-(benzoyl)benzoyl]-beta-D-glucosylamine and 2'-[4-azidosalicylamino]ethyl-1-thio-beta-D-glucoside with K(a)s of approximately 30 microM. The latter also was tested for its potential to specifically label the beta-glucoside-binding site on the synthase, but under the conditions used the binding was found to be nonspecific.

Purification and characterization of an extracellular (1 --> 6)-beta-glucanase from the filamentous fungus Acremonium persicinum

An endo-(1 --> 6)-beta-glucanase has been isolated from the culture filtrates of the filamentous fungus Acremonium persicinum and purified by (NH4)2SO4 precipitation followed by anion-exchange and gel-filtration chromatography. SDS/PAGE of the purified enzyme gave a single band with an apparent molecular mass of 42.7 kDa. The enzyme is a non-glycosylated, monomeric protein with a pI of 4.9 and pH optimum of 5.0. It hydrolysed (1 --> 6)-beta-glucans (pustulan and lutean), initially yielding a series of (1 --> 6)-beta-linked oligoglucosides, consistent with endo-hydrolytic action. Final hydrolysis products from these substrates were gentiobiose and gentiotriose, with all products released as beta-anomers, indicating that the enzyme acts with retention of configuration. The purified enzyme also hydrolysed Eisenia bicyclis laminarin, liberating glucose, gentiobiose, and a range of larger oligoglucosides, through the apparent bydrolysis of (1 --> 6)-beta- and some (1 --> 3)-beta-linkages in this substrate. K(m) values for pustulan, lutean and laminarin were 1.28, 1.38, and 1.67 mg/ml respectively. The enzyme was inhibited by N-acetylimidazole, N-bromosuccinimide, dicyclohexylcarbodi-imide, Woodward's Reagent K, 2-hydroxy-5-nitrobenzyl bromide, KMnO4 and some metal ions, whereas D-glucono-1,5-lactone and EDTA had no effect.

Pharmaceutical services for a homeless population

Participation of pharmacist volunteers in the medication program of a countrywide health care program for homeless persons is described. Pharmacist volunteers were brought in to manage medications for a health care program serving homeless persons in Ramsey County, Minnesota. After the pharmacy program was structured, volunteers were recruited from the community. Pharmacists duties initially focused on product management but were expanded to include establishing and monitoring the program formulary; reviewing patient records and prescriptions for allergies, potential drug interactions, and appropriate dosage; counseling patients on medication use; and consulting with other members of the health care team. The pharmacists' efforts led to improvements in monitoring and stocking of necessary medications. The cost of the pharmacy program decreased from $1800 a month to as little as $300 a month. The value of donated supplies and medications increased from $8,600 in 1991 to over $122,000 in 1994. Pharmacist volunteers helped to improve the cost-effectiveness and quality of medication use in a homeless population.

Potent antisense oligonucleotides to the human multidrug resistance-1 mRNA are rationally selected by mapping RNA-accessible sites with oligonucleotide libraries

Antisense oligonucleotides can vary significantly and unpredictably in their ability to inhibit protein synthesis. Libraries of chimeric oligonucleotides and RNase H were used to cleave and thereby locate sites on human multidrug resistance-1 RNA transcripts that are relatively accessible to oligonucleotide hybridization. In cell culture, antisense sequences designed to target these sites were significantly more active than oligonucleotides selected at random. This methodology should be generally useful for identification of potent antisense sequences. Correlation between oligonucleotide activity in the cell culture assay and in an in vitro RNase H assay supports the proposed role of the enzyme in the mechanism of antisense suppression in the cell.

Barley beta-D-glucan exohydrolases with beta-D-glucosidase activity. Purification, characterization, and determination of primary structure from a cDNA clone

Two beta-glucan exohydrolases of apparent molecular masses 69,000 and 71,000 Da have been purified from extracts of 8-day germinated barley grains and are designated isoenzymes ExoI and ExoII, respectively. The sequences of their first 52 NH2-terminal amino acids show 64% positional identity. Both enzymes hydrolyze the (1,3)-beta-glucan, laminarin, but also hydrolyze (1,3;1,4)-beta-glucan and 4-nitrophenyl beta-D-glucoside. The complete sequence of 602 amino acid residues of the mature beta-glucan exohydrolase isoenzyme ExoII has been deduced by nucleotide sequence analysis of a near full-length cDNA. Two other enzymes of apparent molecular mass 62,000 Da, designated betaI and betaII, were also purified from the extracts. Their amino acid sequences are similar to enzymes classified as beta-glucosidases and although they hydrolyze 4-nitrophenyl beta-glucoside, their substrate specificities and action patterns are more typical of polysaccharide exohydrolases of the (1,4)-beta-glucan glucohydrolase type. Both the beta-glucan exohydrolase isoenzyme ExoI and the beta-glucosidase isoenzyme betaII release single glucosyl residues from the nonreducing ends of substrates and proton-NMR shows that anomeric configurations are retained during hydrolysis by both classes of enzyme. These results raise general questions regarding the distinction between polysaccharide exohydrolases and glucosidases, together with more specific questions regarding the functional roles of the two classes of enzyme in germinating barley grain.

Stereochemical course of glucan hydrolysis by barley (1-->3)- and (1-->3, 1-->4)-beta-glucanases

The stereochemical course of hydrolysis of Laminaria digitata laminarin and barley (1-->3, 1-->4)-beta-glucan by barley (1-->3)-beta-glucanase (E.C. 3.2.1.39) isoenzyme GII and (1-->3, 1-->4)-beta-glucanase (EC 3.2.1.73) isoenzyme EII, respectively, has been determined by 1H-NMR. Both enzymes catalyse hydrolysis with retention of anomeric configuration (e-->e) and may therefore operate via a double displacement mechanism. We predict that all other members of Family 17 of beta-glycosyl hydrolases also follow this stereochemical course of hydrolysis.

Purification and characterization of three extracellular (1-->3)-beta-D-glucan glucohydrolases from the filamentous fungus Acremonium persicinum

Three (1-->3)-beta-D-glucanases (GNs) were isolated from the culture filtrates of the filamentous fungus Acremonium persicinum and purified by (NH4)2SO4 precipitation followed by anion-exchange and gel-filtration chromatography. Homogeneity of the purified proteins was confirmed by SDS/PAGE, isoelectric focusing and N-terminal amino acid sequencing. All three GNs (GN I, II and III) are non-glycosylated, monomeric proteins with apparent molecular masses, estimated by SDS/PAGE, of 81, 85 and 89 kDa respectively. pI values for the three enzymes are 5.3, 5.1, and 4.4 respectively. The pH optimum for GN I is 6.5, and 5.0 for GN II and III. All three purified enzymes displayed stability over the pH range 4.5-10.0. Optimum activities for GN I, II and III were recorded at 65, 55 and 60 degrees C respectively, with both GN II and III having short-term stability up to 50 degrees C and GN I up to 55 degrees C. The purified GNs have high specificity for (1-->3)-beta-linkages and hydrolysed a range of (1-->3)-beta- and (1-->3)(1-->6)-beta-D-glucans, with laminarin from Laminaria digitata being the most rapidly hydrolysed substrate of those tested. K(m) values for GN I, II, and III against L. digitata laminarin were 0.1, 0.23 and 0.22 mg/ml respectively. D-Glucono-1,5-lactone does not inhibit any of the three GNs, some metals ions are mild inhibitors, and N-bromosuccinimide and KMnO4 are strong inhibitors. All three GNs acted in an exo-hydrolytic manner, determined by the release of alpha-glucose as the initial and major product of hydrolysis of (1-->3)-beta-D-glucans, and confirmed by viscometric analysis and the inability to cleave periodate-oxidized laminarin, and may be classified as (1-->3)-beta-D-glucan glucohydrolases (EC 3.2.1.58).

A (1-->3,1-->4)-beta-glucan-specific monoclonal antibody and its use in the quantitation and immunocytochemical location of (1-->3,1-->4)-beta-glucans

Monoclonal antibodies were raised against a (1-->3,1-->4)-beta-glucan-bovine serum albumin (BSA) conjugate. One antibody (BG1) selected for further characterization, was specific for (1-->3,1-->4)-beta-glucan, displaying no binding activity against a (1-->3)-beta-glucan-BSA conjugate and minimal binding against a cellopentaose-BSA conjugate. A range of oligosaccharides was prepared by enzymatic digestion of (1-->3,1-->4)-beta-glucan, purified by size exclusion chromatography and characterized by 1H-NMR and anion exchange chromatography. These (1-->3,1-->4)-beta-oligoglucosides, together with (1-->3)-beta- and (1-->4)-beta-oligoglucosides were used to characterize the binding site of the monoclonal antibody (BG1) by competitive inhibition. The monoclonal antibody showed maximal binding to a heptasaccharide with the structure Glc(1-->3) Glc(1-->4) Glc(1-->4) Glc(1-->3) Glc(1-->4) Glc(1-->4) Glc and was determined to have an affinity constant of 3.8 x 10(4) M-1 for this oligoglucoside. The monoclonal antibody (BG1) has been used to develop a sensitive sandwich ELISA for the specific quantitation of (1-->3,1-->4)-beta-glucans. The assay operates in the range 1-10 ng ml-1 and shows no significant cross-reaction with tamarind xyloglucan, wheat endosperm arabinoxylan or carboxymethylpachyman ((1-->3)-beta-glucan). When used with a second-stage, rabbit anti-mouse gold conjugate and viewed under the electron microscope, the monoclonal antibody probe was found to bind strongly to the walls of the aleurone in thin sections of immature wheat (Triticum aestivum) cv. Millewa grains but not to the middle lamella region.(ABSTRACT TRUNCATED AT 250 WORDS)

Numbers and quality of oocytes after induction of multiple folliculogenesis in women and in mice with different lots of human menopausal gonadotropins

OBJECTIVE

To develop a murine in vivo bioassay that is sensitive to inherent variability of hMG.

DESIGN

Female F1 hybrid mice were mated after injection with fixed dosages of each of four lots of hMG. Oocytes/embryos were collected and monitored during 5 days of culture. Outcome measures were compared with retrospective outcomes of ovarian stimulation of women with the same hMG lots. The bioassay was then used to compare biopotencies of six different lots of hMG.

SETTING

Center for assisted reproductive technology.

INTERVENTIONS

None.

PATIENTS

Outcomes of controlled ovarian stimulation and IVF were retrospectively analyzed from 43 patients.

MAIN OUTCOME MEASURES

Numbers of oocytes/embryos recovered, numbers fertilized, and numbers progressing beyond fertilization.

RESULTS

Differences in biopotencies of hMG lots in the murine in vivo bioassay were consistent with differences in outcomes of patients treated with the same hMG lots during controlled ovarian stimulation. Bioassay outcomes also differed between different lots of hMG.

CONCLUSION

The bioassay described in this study is sensitive to between-lot differences in hMG that affect follicle recruitment and oocyte quality in women (and in mice). In this respect, the bioassay could be of value in screening hMG lots, before its exploitation in a patient population. One such application is explored.

The use of surrogate gestational carriers for assisted reproductive technologies

OBJECTIVES

We determined the effect of embryo transfer, zygote intrafallopian transfer, and frozen embryo transfer on clinical outcomes after surrogate gestational transfers.

STUDY DESIGN

Prospective randomization was carried out.

RESULTS

Forty-five infertile couples were matched with a gestational surrogate carrier and underwent 81 cycles of embryo transfer with various assisted reproductive technologic procedures. Nineteen cycles produced a clinical pregnancy, with delivery in 15 of 81 cycles (18.5% live-birth rate). Fifteen of the 45 couples (33%) had a child from the surrogate gestational carrier program.

CONCLUSION

No significant differences in clinical outcome were observed on the basis of the type of procedure performed or the age of the patient.

Identification of glutamic acid 105 at the active site of Bacillus amyloliquefaciens 1,3-1,4-beta-D-glucan 4-glucanohydrolase using epoxide-based inhibitors

Bacillus amyloliquefaciens 1,3-1,4-beta-D-glucan 4-glucanohydrolase (EC 3.2.1.73) was modified by the mechanism-based, affinity-labeling reagent [14C](3,4)-epoxybutyl beta-D-cellobioside. Following partial inactivation a completely inactivated enzyme preparation containing 1.1 mol of covalently bound inhibitor/mol of protein was obtained by chromatography on a cellulosic matrix. The inactivated enzyme was digested with endoproteinase Glu-C and radioactive peptides purified by reversed-phase high performance liquid chromatography (HPLC). The affinity label was esterified exclusively to the gamma-carboxylate of Glu105 in the sequence Gly-Thr-Pro-Trp-Asp-Glu-Ile-Asp-Ile-Glu109. The sequence motif Glu-(Ile/Leu)-Asp-Ile is found in many glucanases and xylanases and may therefore serve to identify the catalytic nucleophile in beta-glycanases, which otherwise exhibit a low degree of sequence identity. The esterification of Glu105 by the affinity label abolished endoproteinase Glu-C-mediated hydrolysis of the Glu-Ile106 peptide bond. Identification of phenylthiohydantoin-Glu105 during automated sequence analysis was not possible unless the affinity label was liberated by prior base hydrolysis. These observations formed the basis for the development of a highly sensitive approach for the identification of catalytic carboxylates in polysaccharide hydrolases employing non-radioactive inhibitors, comparative HPLC mapping, electrospray mass spectrometry, and Edman degradation.

Kinetic characteristics of alpha 1-adrenergic contractions in human corpus cavernosum smooth muscle

Kinetic studies were conducted on the contractile response elicited by phenylephrine (PE) activation of the alpha 1-adrenergic receptor subtype in vascular smooth muscle isolated from the corpus cavernosum of impotent men. PE-induced contractions were separated into distinct phasic and tonic components, and the tonic portion was analyzed using a first-order rate equation to determine the maximal rate constant for onset of contraction (kobs max) and the maximum amplitude of the steady-state contractile response (Req max). The kobs max value in tissues from insulin-dependent diabetic patients was significantly greater than that in tissues from either noninsulin-dependent diabetics or nondiabetics. Additionally, the mean kobs max value in older patients (60-70 yr) was significantly greater than the mean kobs max value in younger patients (32-59 yr). Significant diabetes-related, but not age-related, alterations were also found in Req max. The observed changes in contractility resulted in dramatic age- and pathology-dependent alterations in the initial rate and/or magnitude of PE-induced response generation. These kinetic studies extend our previous observations at steady state and provide further evidence for heightened corporal tissue tone in the etiology of erectile dysfunction.

Ovarian responses to menopausal gonadotropins in groups of patients with differing basal growth hormone levels

OBJECTIVE

To investigate the relationship between endogenous serum levels of human growth hormone (hGH) and ovarian response to human menopausal gonadotropins (hMG).

DESIGN

Retrospective analysis of patient response to hMG.

SETTING

Center for assisted reproductive technology.

PATIENTS

Eighty women who had undergone controlled ovarian hyperstimulation with hMG. Basal levels of hGH in sera from 40 of these patients were less than 5.0 microIU/mL (low hGH), values for the remaining 40 were greater than 5.0 microIU/mL (high hGH). Levels of hGH in day 2 sera were analyzed against numbers of oocytes recovered in an additional 182 patients.

MAIN OUTCOME MEASURES

Serum estradiol (E2) levels and numbers of oocytes recovered at oocyte pick-up.

RESULTS

Average (+/- SE) levels of hGH in sera of high-hGH and low-hGH patients were 10.2 +/- 0.6 and 2.47 +/- 0.3 microIU/mL, respectively (P less than 0.05). Respective peripheral levels of insulin-like growth factor-I were 105.3 +/- 2.9 and 97.2 +/- 2.8 ng/mL. Levels of E2 in serum of high-hGH patients exceeded respective (P less than 0.05) low-hGH values throughout folliculogenesis, and more oocytes were recovered from high-hGH patients (8.1 +/- 0.9 versus 4.7 +/- 0.5 for low-hGH patients; P less than 0.05). Serum progesterone values did not differ. Higher day 2 hGH levels were associated with higher numbers of oocytes recovered after controlled ovarian hyperstimulation.

CONCLUSIONS

The present findings indicate that endogenous hGH may augment gonadotropins during follicle recruitment and during multiple folliculogenesis in women. The phase of maximum ovarian sensitivity to hGH/gonadotropin synergism and the nature of synergism remain unclear.

The beta-glucan synthase from Lolium multiflorum. Detergent solubilization, purification using monoclonal antibodies, and photoaffinity labeling with a novel photoreactive pyrimidine analogue of uridine 5'-diphosphoglucose

The membrane-bound beta-glucan synthase from Italian ryegrass (Lolium multiflorum L.) endosperm cells has been solubilized by both non-ionic and zwitterionic detergents. A complex relationship exists between the ratio of (1----3)-, (1----4)-, and (1----3, 1----4)-beta-glucan products of the solubilized enzyme, the cations present, and the concentration of the uridine 5'-diphosphoglucose substrate. Monoclonal antibodies directed against the beta-glucan synthase complex were generated by immunization of mice with an unfractionated microsomal reparation. Hybridoma cell lines were screened using a combination of indirect enzyme-linked immunosorbent assay followed by an enzyme-capture assay. The purified monoclonal antibodies were used with Pan-sorbin (stablized protein A-bearing staphylococcal cells) to immunoprecipitate an active beta-glucan synthase complex which had been solubilized from a microsomal preparation with 0.6% CHAPS. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of the immunoprecipitated synthase complex revealed four major polypeptides of apparent molecular mass 30, 31, 54, and 58 kDa together with several minor components. The immunoprecipitated beta-glucan synthase complex was capable of synthesizing both (1----3)- and (1----4)-beta-glucans. A new photoreactive pyrimidine analogue of uridine 5'-diphosphoglucose, 5-[3-(p-azidosalicylamide]allyl-uridine 5'-diphosphoglucose was synthesized in a three-step reaction sequence involving mercuration of UDP-Glc, alkylation of 5-Hg-UDP-Glc, and acylation of 5-(3-amino)allyl-UDP-Glc and characterized by chemical and spectroscopic analysis. The analogue inhibits (Kiapp 16 microM) and, upon UV irradiation, irreversibly inactivates the beta-glucan synthase. The analogue was iodinated with Na125I to give a radiolabeled, photoreactive compound, and was used in photoaffinity labeling of UDP-Glc pyrophosphorylase, UDP-Glc dehydrogenase, and several putative UDP-Glc-binding proteins from L. multiforum. The radiolabeled analogue specifically labeled the 31-kDa polypeptide in the immunoprecipitated synthase complex. The photolabeling of this polypeptide is strictly dependent on UV irradiation, is blocked by uridine 5'-diphosphoglucose and uridine 5'-diphosphate, and reaches saturation at analogue concentrations above 300 microM. These results indicate that the 31-kDa polypeptide in the beta-glucan synthase complex bears a uridine 5'-diphosphoglucose-binding site and is involved in the catalysis of beta-glucan synthesis.

The location of (1→3)-β-glucans in the walls of pollen tubes of Nicotiana alata using a (1→3)-β-glucan-specific monoclonal antibody

The location of the (1→3)-β-glucan, callose, in the walls of pollen tubes in the style of Nicotiana alata Link et Otto was studied using specific monoclonal antibodies. The antibodies were raised against a laminarinhaemocyanin conjugate. One antibody selected for further characterization was specific for (1→3)-β-glucans and showed no binding activity against either a cellopentaose-bovine serum albumin (BSA) conjugate or a (1→3, 1→4)-β-glucan-BSA conjugate. Binding was inhibited by (1→3)-β-oligoglucosides (DP, 3-6) with maximum competition being shown by laminaripentaose and laminarihexaose, indicating that the epitope included at least five (1→3)-β-linked glucopyranose residues. The monoclonal antibody was determined to have an affinity constant for laminarihexaose of 2.7. 10(4)M(-1). When used with a second-stage gold-labelled, rabbit anti-mouse antibody, the monoclonal antibody probe specifically located the (1→3)-β-glucan in the inner wall layer of thin sections of the N. alata pollen tubes.

Growth hormone in serum of women during the menstrual cycle and during controlled ovarian hyperstimulation

STUDY OBJECTIVE

To investigate the interrelationships between circulating levels of endogenous human growth hormone (hGH), gonadotropins, estradiol (E2), and progesterone (P).

DESIGN

Retrospective.

SETTING

Assisted reproductive technology center.

PATIENTS

Nine normally cycling women from whom blood samples were drawn daily; 18 patients undergoing controlled ovarian hyperstimulation.

RESULTS

During the menstrual cycle, average (+/-SE) hGH levels in serum ranged between 7.97 +/- 2.71 microIU/mL on day 11 and 2.11 +/- 0.38 microIU/mL on day 22. Serum hGH levels did not correlate with peripheral levels of follicle-stimulating hormone (FSH), luteinizing hormone, P, or E2 and were related to the serum E2:FSH ratio (adhibited as an index of ovarian response to FSH) on cycle day 10 only. Levels of hGH in sera of patients undergoing controlled ovarian hyperstimulation were near 4 microIU/mL and were directly related to peripheral E2 levels at the time of induction of oocyte maturity. When corrected for differences in follicle number between stimulated patients, changes in serum E2 content were independent of respective hGH levels.

CONCLUSION

The findings challenge speculation that endogenous peripheral hGH content might relate to ovarian responsiveness to FSH.

Active site-directed inhibition by optically pure epoxyalkyl cellobiosides reveals differences in active site geometry of two 1,3-1,4-beta-D-glucan 4-glucanohydrolases. The importance of epoxide stereochemistry for enzyme inactivation

1,3-1,4-beta-D-Glucan 4-glucanohydrolases (EC 3.2.-1.73) from Bacillus subtilis and barley (Hordeum vulgare) with identical substrate specificities but unrelated primary structures have been probed with (R,S)-epoxyalkyl (-propyl, -butyl, -pentyl) beta-cellobiosides and with optically pure (3S)- and (3R)-3,4-cellobiosides as active site-directed inhibitors. The optimal aglycon length for inactivation differs for the two enzymes, and they are differentially inhibited by the pure epoxybutyl beta-cellobioside diastereoisomers. The (3S)-epoxybutyl beta-cellobioside inactivates the B. subtilis enzyme much more efficiently than does the (3R)-isomer, whereas the reverse is true for the barley enzyme. Both enzymes are inactivated by a mixture of the stereoisomers at a rate intermediate of that observed with the individual isomers. The two beta-glucan endohydrolases may therefore employ sterically different mechanisms to achieve glycoside bond hydrolysis in their common substrate. The efficiency and specificity of epoxide-based "suicide" inhibitors may be enhanced significantly by the use of inhibitors bearing only one stereoisomeric form of the epoxide group.

Physical structure of lithium niobate thin films

Thin films of LiNbO have been RF sputter deposited on silicon and sapphire substrates. A number of analytical techniques have been used to determine the physical structure of these films. This analysis shows that the resulting films are stoichiometric LiNbO(3) and oriented polycrystalline in nature. It is now possible to consider applications which utilize the unique properties of these films.

Between-lot variability in chromatographic and biochemical properties of hMG

Ten lots of dissociated hMG were characterized by reverse-phase gradient high-performance liquid chromatography. Areas of 12 discrete peaks were directly related to dosages of hMG injected. The lots were further analysed for immunoactive-FSH (41.6-106.2 IU/ampule), immunoactive-LH (11.0-20.4 IU/ampule), bioactive-LH (2.7-17.1 IU/ampule) and bioactive-hMG (149-298 pg E2/mIU immunoactive-FSH/ml). Relationships between integrated areas of the HPLC peaks and biochemical properties of the hMG lots were analysed by stepwise multiple linear regression. Between-lot differences in immunoactive-LH and immunoactive-FSH were related to HPLC peak areas (p less than 0.05); differences in bioactive-LH were not. Areas of 8 peaks were related to differences in bioactive-hMG activity, facilitating close approximation of bioactive-hMG from the derived multi-linear model (p less than 0.001). Rapid characterization of hMG by HPLC is of relevance as recent reports have shown that ovarian responses and pregnancy outcomes of patients are related to the immunoactive and bioactive gonadotropin content of hMG preparations used to induce multiple folliculogenesis before oocyte aspiration, in vitro fertilization, and embryo replacement.

Effect of human follicular fluids from pregnant and nonpregnant patients on the development of mouse zygotes in vitro

Mouse zygotes were cultured in medium containing follicular fluid from patients who had follicles containing oocytes which fertilized, did not fertilize, or were atretic and who did or did not become pregnant after in vitro fertilization and embryo replacement. The inhibitory effect was least with the follicular fluid from follicles in which the oocytes subsequently fertilized, greater when the oocytes did not fertilize, and most inhibitory when the follicle contained an atretic oocyte. More mouse zygotes developed to blastocysts when culture medium was supplemented with follicular fluid from patients who became pregnant compared to those who did not become pregnant. There was no difference in pregnancy outcome when an oocyte which subsequently fertilized was obtained from the follicle. These results indicate that follicles contain a substance(s) which inhibits mouse zygote development in vitro and that the inhibitory activity is related to the developmental potential of the oocyte in the follicle.

Suboptimal laboratory conditions can affect pregnancy outcome after embryo transfer on day 1 or 2 after insemination in vitro

We have demonstrated that the replacement of pronuclear stage human embryos on the day after insemination in IVF-ET results in a pregnancy rate as good as, if not better than, the rate after ET on day 2. The pregnancy rate appears to be influenced by the culture environment used for the gametes. We would recommend that ET be undertaken as soon as possible after insemination on day 1 so that if suboptimal culture conditions are present, they do not have sufficient time to affect the viability of the embryos and reduce the subsequent chance of pregnancy after replacement. If culture conditions have been optimized there is no difference in pregnancy rate after embryo transfer on day 1 or day 2 and one can then replace embryos on either day and expect the pregnancy rate obtained in either case to be similar.

Concentrations of follicle regulatory protein, steroids and gonadotrophins in antral fluids from women stimulated with metrodin and hCG

Concentrations of immunoreactive follicle regulatory protein (FRP) were determined in 184 follicular fluid samples recovered from 30 patients in whom ovarian stimulation before oocyte recovery and in-vitro fertilization was induced with FSH (150 i.u./day). Ovum recovery was scheduled when the diameters of greater than or equal to 2 follicles reached 15-17 mm and serum oestradiol values were 740 pM/follicle. The mean level of FRP in fluid from follicles yielding oocytes which fertilized and cleaved within 48 h of recovery (24.4 +/- 3.08 immunoreactive units [IRU]/ml; 1 IRU = approximately 1 ng pig FRP) was higher than that in fluid from follicles yielding oocytes which did not fertilize (10.5 +/- 1.67 IRU/ml, P less than 0.05). FRP in fluid from follicles yielding oocytes which fertilized but did not cleave within 48 h of recovery was 17.2 +/- 2.89 IRU/ml. Overall, concentrations of FRP did not correlate with follicular fluid volume or with FSH or LH concentrations, but were positively related to prolactin, oestradiol and total protein levels (P less than 0.04). The results indicate that the FRP content of follicular fluid may be predictive of follicle/oocyte maturity. A dose-dependent increase in release of FRP by pig granulosa cells cultured in medium supplemented with 10-100 ng prolactin/ml was demonstrated. Prolactin may, therefore, be an important determinant of FRP production by granulosa cells.

Characterization of the hydroxyproline-rich protein core of an arabinogalactan-protein secreted from suspension-cultured Lolium multiflorum (Italian ryegrass) endosperm cells

An arabinogalactan-protein (AGP) purified from the filtrate of liquid-suspension-cultured Italian-ryegrass (Lolium multiflorum) endosperm cells by affinity chromatography on myeloma protein J539-Sepharose was deglycosylated with trifluoromethanesulphonic acid to remove polysaccharide chains that are covalently associated with hydroxyproline residues in the peptide component of the proteoglycan. The protein core, which accounts for less than 10% (w/w) of the intact proteoglycan, was purified by h.p.l.c. It has an apparent Mr of 35,000, but reacts very poorly with both Coomassie Brilliant Blue R and silver stains. Amino-acid-sequence analysis of the N-terminus of the h.p.l.c.-purified protein core and of tryptic peptides generated from the unpurified protein reveals a high content of hydroxyproline and alanine. These are sometimes arranged in short (Ala-Hyp) repeat sequences of up to six residues. Polyclonal antibodies raised against the protein core do not cross-react with native AGP, the synthetic peptide (Ala-Hyp)4, poly-L-hydroxyproline or poly-L-proline. The results suggest that the polysaccharide chains in the native AGP render the protein core of the proteoglycan inaccessible to the antibodies and that the immunodominant epitopes include domains of the protein other than those rich in Ala-Hyp repeating units.

Spontaneously resorbing ectopic pregnancy: preservation of human chorionic gonadotropin bioactivity despite declining steroid hormone levels

We compared serum hormone profiles of patients with normal intrauterine pregnancies (n = 14), spontaneously resorbing ectopic pregnancies (n = 10), and viable ectopic pregnancies (n = 26). Hormone profiles were evaluated at 5 to 8 weeks' gestational age. Ectopic pregnancies were diagnosed by laparoscopy; intrauterine gestations were confirmed by ultrasonography. Immunoreactive beta-human chorionic gonadotropin, progesterone, estradiol, and 17-hydroxyprogesterone were measured by radioimmunoassay. Bioactive human chorionic gonadotropin was measured by a modified mouse Leydig cell bioassay. Diminished steroid production was noted in ectopic pregnancies; levels in serum of patients with resorbing ectopic pregnancies were lower than values expressed in viable ectopic pregnancies (p less than 0.01). Serum levels of human chorionic gonadotropin bioactivity correlated closely with immunoreactive human chorionic gonadotropin in all three groups (r = 0.81, p less than 0.01). Ratios of bioactive human chorionic gonadotropin to immunoreactive beta-human chorionic gonadotropin were similar (0.93 +/- 0.26 in resorbing ectopic pregnancies, 1.11 +/- 0.16 in viable ectopic pregnancies, and 0.90 +/- 0.10 in intrauterine pregnancies). We conclude that although reduced serum levels of steroids noted in ectopic pregnancy suggest an impairment in corpus luteum activity, diminished steroid production was not attributable to lower human chorionic gonadotropin bioactivity.

Responses of patients to different lots of human menopausal gonadotropins during controlled ovarian hyperstimulation

Responses of patients treated with different lots of human menopausal gonadotropin (hMG) during controlled ovarian hyperstimulation were analyzed. Levels of luteinizing hormone (LH) in serum varied between groups of patients treated with different hMG lots, serum follicle-stimulating hormone (FSH) levels did not differ. In the analysis of levels of estradiol (E2) in serum of patients pretreated with leuprolide acetate (gonadotropin-releasing hormone analog; GnRH-a), there was an interaction between hMG lot and day of stimulation. E2 levels/follicle also diverged between hMG batches as ovum pick-up approached. Within the groups of patients pretreated with GnRH-a, serum FSH/LH ratios varied between 5 and 20, with a batch x day interaction. Ongoing pregnancy rates in the hMG-treatment groups ranged between 0/24 and 7/33 (21%).

Tailoring a commercial radioimmunoassay to the range of levels of progesterone occurring in human serum during controlled ovarian hyperstimulation and following embryo/gamete transfer

While the Pantex direct P radioimmunoassay is used widely in programs of assisted conception, its sensitivity and range do not encompass the wide range of levels of P in serum of many patients during COH and through the first trimester of pregnancy. The present communication details minor modifications to the proprietary Pantex assay which accommodate these requirements. The nature of the changes does not compromise the performance characteristics or simplicity of the original assay and facilitates precise, accurate, and rapid measurement of serum P between 0.05 and 1280 ng/ml.

Levels of interleukin-2 receptor in serum of patients during the menstrual cycle and following embryo/gamete transfer

In an attempt to establish whether nidation elicits a measureable systemic immunologic response in vivo, levels of interleukin-2 receptor (IL-2R) have been determined in serum drawn from 34 pregnant patients (IUP) immediately before embryo/gamete transfer, and 7 and 14 days later. For comparison, these same values were determined for 41 subjects who did not conceive, and for 18 who spontaneously aborted (SAB) during the first trimester of gestation. Serum IL-2R values were near 320 U/ml and did not differ between days within outcomes, or within days between outcomes. Furthermore, levels of IL-2R and beta-hCG in serum were not interrelated on days 7 or 14 of pregnancy (SAB or IUP). Serum IL-2R levels did not change during the menstrual cycle. The present results appear to traverse presumptive elements of existing hypotheses of "placental immunotropism."

Uterine presensitization and embryo survival and growth in Booroola Merino x South Australian Merino ewes

The fertility enhancing effects of semen were examined following the intra-uterine insemination of killed spermatozoa plus seminal plasma 17 d prior to insemination with viable spermatozoa. Three experiments were conducted: two on 1.5-yr old and 2.5 to 5.5 yr-old Booroola Merino x South Australian Merino ewes in 1986 and one on 1.5 yr-old ewes in 1987. Differences between treatment and control groups for the percentage of ewes exhibiting estrus by Days 21 and 35 following fertile insemination, the percentage of ewes with viable embryos at Day 35, the number and weight of viable embryos per ewe, the nubmer of caruncular implantation sites and the progesterone level were not statistically significant (P>0.05). There were no statistically significant treatment by experiment interactions for any of the variables examined. Inflammation and edema of the endometrial tissue was not observed following the presensitization treatment.

Gonadotropin and estradiol levels during ovarian stimulation in women treated with leuprolide acetate

Levels of FSH, LH, and estradiol (E2) were measured in the serum of 209 gonadotropin-releasing hormone analogue-treated women and in 202 control subjects during the final 5 days of ovarian stimulation in our in vitro fertilization program. Levels of FSH and E2 in serum of gonadotropin-releasing hormone analogue-treated subjects significantly exceeded control values during the sampling period, whereas LH levels were significantly lower. Concentrations of E2 in serum of gonadotropin-releasing hormone analogue-treated and control subjects were similar when corrected for differences in numbers of follicles aspirated at oocyte retrieval (mean of 8.9 and 7.2 follicles per subject, respectively). Pregnancy rates by diagnostic ultrasound were 18 and 11%, respectively, a statistically significant difference.

Differences in active site structure in a family of beta-glucan endohydrolases deduced from the kinetics of inactivation by epoxyalkyl beta-oligoglucosides

The active sites of a spectrum of beta-glucan endohydrolases with distinct, but related substrate specificities have been probed using a series of epoxyalkyl beta-glycosides of glucose, cellobiose, cellotriose, laminaribiose, laminaritriose, 3O-beta-D-glucosyl-cellobiose and 4O-beta-D-glucosyl-laminaribiose with different aglycon chain lengths. The inactivation of each of the endohydrolases by these compounds results from active site-directed inhibitor action, as indicated by the dependence of the inactivation rate on pH, glycosyl chain length and linkage position, aglycon length, and the protective effect of disaccharides derived from the natural substrates. Comparisons of inhibitor specificity between a Bacillus subtilis 1,3;1,4-beta-D-glucan 4-glucanohydrolase (EC 3.2.1.73), a Streptomyces cellulase (EC 3.2.1.4), a Schizophyllum commune cellulase (EC 3.2.1.4), a Rhizopus arrhizus 1,3-(1,3;1,4)-beta-D-glucan 3(4)-glucanohydrolase (EC 3.2.1.6), and a Nicotiana glutinosa 1,3-beta-D-glucan 3-glucanohydrolase (EC 3.2.1.39) demonstrated different tolerances for glycosyl linkage positions in the inactivation process and a critical role of aglycon length reflecting differences in the active site geometry of the enzymes. For the B. subtilis endohydrolase it was concluded that the aglycon residue of the inhibitor spans the glycosyl binding subsite occupied by the 3-substituted glucosyl residue involved in the glucosidic linkage cleaved in the natural substrate. Appropriate positioning of the inhibitor epoxide group with respect to the catalytic amino acids in the active site is crucial to the inactivation step and the number of glucosyl residues in the inhibitor affects aglycon chain length specificity. The importance of this effect differs between the glucanases tested and may be related to the number of glycosyl binding subsites in the active site.