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PubMed1986

N-acetyltransferase multiplicity and the bioactivation of N-arylhydroxamic acids by hamster hepatic and intestinal enzymes.

The mechanism-based inactivation (suicide inactivation) by N-hydroxyphenacetin (NHP) of N-arylhydroxamic acid N,O-acyltransferase (AHAT) and p-aminobenzoic acid N-acetyltransferase (PABA NAT) activities of a partially purified hamster liver preparation was investigated. The inactivation of both enzyme activities was irreversible, but a partial protection of PABA NAT could be achieved by inclusion of the nucleophile cysteine in the incubation mixture; cysteine did not reduce the extent of inactivation of AHAT by NHP. Hepatic AHAT and PABA NAT activities were separated by affinity chromatography, and the resolved enzyme activities were subjected to incubation in the presence of NHP, N-hydroxy-2-acetamidofluorene (N-OH-AAF), and N-hydroxy-4-acetamidobiphenyl (N-OH-AABP); AHAT, but not PABA NAT, was inactivated by NHP, N-OH-AAF and N-OH-AABP. Incubation of hamster heptic PABA NAT with radiolabeled N-OH-AAF resulted in the formation of only 15% as much fluorenylamine-tRNA adduct as was formed when N-OH-AAF was bioactivated with hamster hepatic AHAT. Hamster intestinal AHAT and PABA NAT activities also were resolved by affinity chromatography; the intestinal AHAT fractions were much more effective than the PABA NAT fractions in bioactivating N-OH-AAF. These results demonstrate that hamster liver and intestine contain at least two arylamine transacetylating activities, one of which is much more effective than the other in the bioactivation of toxic and carcinogenic N-arylhydroxamic acids.

2-Acetylaminofluorene↗

PubMed1999

Inhibitory effect of plasma obtained from hypophysectomized and control women on the assay of bioactive luteinizing hormone.

The purpose of this study was to determine the effect of components of female plasma on the value of bioactive luteinizing hormone (LH), especially in the presence of low immunological LH value. Using both an immunoradiometric assay (IRMA) and rat Leydig cell bioassay, immunoreactive (I) and bioactive (B) LH were assessed in plasma collected from women during a gonadotrophin releasing hormone (GnRH) test performed on day 7 of a spontaneous cycle. Two modes of response to an acute administration of GnRH were defined: normal production of gonadotrophins (group I) and excessive secretion (group II) associated with a significant difference in the B/I-LH ratio between the two groups. The B/I-LH ratio did not vary with sampling time during the test in either group. The addition of LH-free plasma collected from hypophysectomized women caused a 30% decrease in testosterone production compared to control values (in the presence or absence of hLH standard). A partial restoration of testosterone production was observed if plasma was first treated with PEG 12%. The inhibitory factor(s) was also present in plasma from ovulatory women, even after treatment by an antibody against the entire LH molecule. The effect of normal (A) or low I-LH plasma (B) on testosterone production varied strongly according to the plasma volume added to the bioassay, as well as to plasma treatments. Diethylether treatment caused a 50% decrease in testosterone secretion for plasma B (but not for A) whereas a diminution of the steroidogenesis is observed after a PEG treatment of plasma A (but not for B), suggesting that different inhibitory factors are present in plasmas A and B. Therefore the LH bioactivity measured in the rat Leydig cell assay, in terms of testosterone output, seems to represent a balance between the LH molecule and the presence of inhibitory factors in the plasma.

Adult↗

PubMed1999

Bioactivity of prolactin isoforms: lactation and recovery of menses in nursing women.

To assess whether plasma prolactin (PRL) characteristics relate to lactogenesis and absence or presence of menstrual cycles, we measured bioactive PRL (BIO-PRL) using the Nb2 assay, immunoreactive PRL (IR-PRL) by radio-immunoassay, calculated equations describing the BIO-PRL-IR-PRL relationship and separated charged PRL isoforms (by chromatofocusing) in five amenorrhoeic and five cycling nursing women at 6 months postpartum and in 10 cycling non-nursing women. Plasma samples were drawn before and 30 min after a suckling episode at 0800, 1600 and 2400 h in nursing women and at the same hours in non-nursing women. BIO-PRL and IR-PRL concentrations were highest in amenorrhoeic nursing women, intermediate in cycling nursing women and lowest in cycling non-nursing women. The BIO-PRL-IR-PRL relationship shows that a given amount of IR-PRL corresponds to equivalent amounts of BIO-PRL in cycling nursing and cycling non-nursing women, and to a larger extent in amenorrhoeic nursing women. IR-PRL was present in plasma as several charge isoforms. Bioactive isoforms eluting at pH 6.0-5.1 were found in amenorrhoeic and cycling nursing women, reaching similar concentrations after suckling. Bioactive isoforms eluting at pH 7.0-6.1 were found only in amenorrhoeic nursing women. We speculate that isoforms eluting at pH 6.0-5.1 may play a role in lactation and isoforms eluting at pH 7.0-6.1, in lactational amenorrhoea.

Adult↗

PubMed2004

Poly(I:C) used for human dendritic cell maturation preserves their ability to secondarily secrete bioactive IL-12.

Dendritic cells (DC) are professional antigen-presenting cells that play a central role in the control of immunity. Mature DC are characterized by high expression levels of MHC and co-stimulatory molecules, and by the secretion of IL-12, a key cytokine for the priming of cytotoxic T lymphocytes. Here, we have compared different maturation stimuli to reproducibly generate stable mature DC secreting high amounts of bioactive IL-12p70. We have compared soluble human trimeric CD40 ligand (sCD40L) combined with IFN-gamma, poly(I:C), a cocktail of cytokines (IL-1beta, IL-6 and tumor necrosis factor-alpha) with prostaglandin E(2) and lipopolysaccharide. A major concern, however, is whether DC, that have already produced high amounts of IL-12p70 during the maturation step, are still capable of secreting IL-12p70 after in vivo administration at the time of interaction with the targeted T cells. To mimic that situation, mature DC generated by those methods were compared for their ability to secrete IL-12p70 in the absence of IFN-gamma, using sCD40L. We observed a second consistent secretion of bioactive IL-12p70 upon subsequent sCD40L stimulation only when poly(I:C) was used as the maturating agent. Our data suggest that, for clinical use, poly(I:C) may be one of the most appropriate agents to generate stable mature DC. These mature DC might generate in vivo effective immune responses after injection, because they retain the ability to secrete bioactive IL-12 after CD40 ligation.

Antigens, Surface↗

PubMed1987

An in-vitro comparison of the intraphagocytic bioactivity of erythromycin and roxithromycin.

The binding to human polymorphonuclear leucocytes and the intracellular bioactivity of the macrolide antibiotics erythromycin and roxithromycin on Legionella micdadei, Listeria monocytogenes and Staphylococcus aureus were investigated in vitro by the combination of a fluorochrome microassay and a radioassay. Polymorphs with intact or absent membrane-associated oxidative metabolism were used to investigate the interactions which may occur between the intrinsic oxygen-dependent antimicrobial systems of human polymorphs and the test antibiotics, in the elimination of intracellular microbial pathogens. Elimination of O2-dependent antimicrobial systems with retention of phagocytic activity was achieved by using polymorphs from children with chronic granulomatous disease NaF-pulsed normal polymorphs. Both antimicrobial agents were actively concentrated by polymorphs. Erythromycin was concentrated ten-fold and roxithromycin approximately thirty-fold above extra cellular levels. Both agents possessed intracellular bacteriostatic activity for all three test microbial pathogens. Depletion of polymorph O2-dependent intrinsic antimicrobial systems interfered with the intracellular bioactivity of both antibiotics. This emphasizes the importance of interactions between cell-associated antibiotics and phagocyte antimicrobial systems in the elimination of intracellular microbial pathogens. Like erythromycin, roxithromycin is concentrated by human phagocytes and is bioactive intracellularly.

Bacteria↗

PubMed1999

10-Formyl-dihydrofolic acid is bioactive in human leukemia cells.

The bioactivity of 10-formyl-7,8-dihydrofolic acid and 10-formyl-folic acid was determined in human leukemia (CCRF-CEM) cells grown in a folate-depleted medium containing methotrexate. Excess 10-formyl-7,8-dihydrofolic acid, (but not 10-formyl folic acid) supported the growth of these cells, but it was less potent than5-formyl-5,6,7,8-tetrahydrofolic acid (a control). 10-formyl-7, 8-dihydrofolic acid (not 10-formyl folic acid) was active as substrate for aminoimidazole carboxamide ribotide transformylase and dihydrofolate reductase. This is the first experimental evidence that 10-formyl-7,8-dihydrofolic acid is a bioactive folate in mammalian cells. These experiments and several other lines of evidence in the literature suggest that 10-formyl-folic acid must be metabolized to bioactive folate by enteric bacteria before it can be utilized by the vertebrate host.

Analysis of Variance↗

PubMed2003

Use of exfoliated cells from target tissues to predict responses to bioactive food components.

A host of bioactive food components have been proposed to promote health and reduce the risk of disease states. It is clear that not all individuals respond identically to these essential and nonessential food components. Genetic polymorphisms may influence absorption, metabolism and accumulation of bioactive food components, thereby influencing their actions in target tissues. Unfortunately, serum concentrations of bioactive food components may not correlate with tissue concentrations and may therefore under- or overestimate the response in target tissues. Exfoliated cells may be useful to assess the actions of nutrients in specific tissues. Although not extensively examined, evidence already suggests the usefulness of these cells in predicting changes in gene expression, DNA methylation, DNA damage, protein expression and accumulation of dietary components. Although there are limitations on the collection of exfoliated cells, the inaccessibility of tissues they can represent raises intriguing possibilities for their ability to predict the outcome of nutritional intervention studies.

Biological Products↗

PubMed2004

Bioactive properties of milk proteins with particular focus on anticariogenesis.

Beyond nutrition, there is an increasing amount of data and information to demonstrate a bioactive role for dairy components in adults including a role in prevention of dental caries. Specifically, the casein fraction and hydrolysates thereof have been the focus of researchers investigating cariogenicity prevention. Tooth enamel is a polymeric substance consisting of crystalline calcium phosphate embedded in a protein matrix. Dental caries develop by acidic demineralization (calcium and phosphorus solubilization) of tooth enamel. Demineralization occurs directly (acidic food consumption) or indirectly (by fermentation products of dental plaque odontopathogenic bacteria growing on residual food particles between teeth or adhering to the plaque). Research efforts with milk derived bioactive peptides have focused on inhibition of cariogenic, plaque-forming bacteria, inhibition of tooth enamel demineralization, and subsequent enamel remineralization. Caseinophosphopeptides (CPP) and glycomacropeptide (GMP) have been patented for use in common personal hygiene products to prevent dental caries. Research has shown CPP and GMP to be growth inhibitory to the cariogenic bacteria Streptococcus mutans and other species. Additionally, CPP forms nanoclusters with amorphous calcium phosphate (AMP) at the tooth surface to provide a reservoir of calcium and phosphate ions to maintain a state of super saturation with respect to tooth enamel. This would buffer plaque pH, and also provide ions for tooth enamel remineralization. Glycosidic structures attached to GMP are important to numerous bioactive properties of the peptide including anticariogenicity. Like CPP, GMP has shown inhibitory activity to enamel demineralization and promotes tooth enamel remineralization.

Amino Acid Sequence↗

PubMed2004

Molecular targets for bioactive food components.

Mounting evidence points to dietary habits as an important determinant of cancer risk and tumor behavior. Although the linkages with diet are intriguing, the literature is also laden with inconsistencies. The reasons for these inconsistencies are likely multi-factorial, but probably reflect variations in the ability of bioactive constituents to reach or affect critical molecular targets. Fluctuations in the foods consumed not only influence the intake of particular bioactive components, but may alter metabolism and potentially influence the sites of action of both essential and nonessential nutrients. Genetic polymorphisms are increasingly recognized as another factor that can alter the response to dietary components (nutritional transcriptomic effect) by influencing the absorption, metabolism, or sites of action. Likewise, variation in DNA methylation patterns and other epigenetic events that influence overall gene expression can be influenced by dietary intakes. Furthermore, variation in the ability of food components to increase or depress gene expression (nutrigenomic effect) may account for some of the observed inconsistencies in the response to dietary change. Because a host of food components are recognized to influence phosphorylation and other posttranslational events, it is also likely that these and other proteomic modifications account for at least part of the response and variation that is reported in the literature. Collectively, it is clear that bioactive food components can influence a number of key molecular events that are involved in health and disease resistance. As the era of molecular nutrition unfolds, a greater understanding of how these foods and components influence cancer will surely arise. Such information will be critical in the development of effective tailored strategies for reducing cancer burden. Just as important, however, is that as this information unfolds it is utilized within a responsible bioethical framework.

Animals↗

PubMed2005

Nutritional "omics" technologies for elucidating the role(s) of bioactive food components in colon cancer prevention.

Evidence continues to implicate dietary components and genetic susceptibilities as important determinants of cancer risk and tumor behavior. Variation in cancer incidence among and within populations with similar dietary patterns suggests that an individual's response may reflect interactions with genetic factors, which may modify gene, protein, and metabolite expression patterns. Nutrigenomics, defined as the interaction between nutrition and an individual's genome, will likely provide important clues about responders and nonresponders. In this symposium, the role of bioactive food components in colon cancer susceptibility was used to exemplify the application of "omic" technologies for cancer prevention. Topics that were addressed included dietary changes and gene polymorphisms (nutrigenetics), DNA methylation (nutritional epigenomics), gene expression (nutritional transcriptomics), altered formation or bioactivation of proteins (proteomics), and characterizing how the quantity and timing of exposure influence small molecular weight cellular constituents (metabolomics). The final presentation focused on exfoliated cells as a surrogate sample for the evaluation of bioactive food components in cancer prevention. The goal of the symposium was to provide an example of each of the "omic" technologies as they relate to nutrition, cancer risk, and tumor behavior, and to help the participants understand that an integrated framework that simultaneously examines all of the "omic" technologies is needed.

Colonic Neoplasms↗

PubMed2005

Sorting out bioactivity in flavonoid mixtures.

Natural polyphenolic compounds, including flavonoids, which are synthesized by plants, have repeatedly been linked to multiple health benefits, but specific bioactive compounds or individualized roles have been difficult to interpret or to assign. This limitation has prevented the development of robust dietary recommendations. This paper describes a plant-cell-culture production approach that provides uniform yields of abundant natural mixtures of flavonoids from small molecules to high molecular weight oligomers and polymers. The flavonoids correspond to compounds produced in nature by the same plant genotypes; but, through elicitation tactics, the levels and the profiles of the flavonoid yield can be enhanced, and isolation from cell cultures is more rapid and streamlined than isolation from in vivo plant tissues. Introduction of (14)C sucrose to the cell-culture medium enabled the recovery and the identification of biolabeled flavonoid mixtures, which could be easily tracked in serum of rats after gavage. The biolabeled materials are now being investigated to determine tissue localization, structures of bioactive components, and the interactions between flavonoid components that contribute to bioactive potential.

Animals↗

PubMed2006

The stimulatory role of human cytochrome b5 in the bioactivation activities of human CYP1A2, 2A6 and 2E1: a new cell expression system to study cytochrome P450-mediated biotransformation (a corrigendum report on Duarte et al. (2005) Mutagenesis 20, 93-100).

This corrigendum report describes the study of the comparison of human cytochrome b(5) (b(5)) with rat b(5) when coupled with human cytochrome P450 CYP1A2, 2A6 or 2E1. Results indicate a role of the N-terminal part of b(5) in the coupling with CYP. Indeed, the plasmid pLCM-b(5)-RED used in our former study on b(5) [Duarte et al. (2005) Mutagenesis, 20(2), 193-100] erroneously contained rat b(5). Plasmid pLCM-b(5)-RED was corrected with human b(5) and subsequently all experimental work was repeated as was described for the rat b(5) plasmid. Although absolute values of contents and activities were lower, all key-findings as found for rat b(5) could be confirmed using human b(5). The physiological relevant co-expression of the members of the cytochrome P450 complex, CYP, NADPH-cytochrome P450 oxidoreductase (RED) and human b(5) could be demonstrated in the different BTC strains, as was found before. The stimulatory effect of human b(5) on the activity of CYP1A2, CYP2A6 and CYP2E1 was in general similar, when compared with rat b(5), though less quantitatively pronounced. This was both the case when using membrane preparations as well as by the bioactivation of procarcinogens using the bacterial mutagenicity assay. Human b(5) stimulated the bioactivation of all compounds as described for rat b(5), except for CYP1A2 mediated bioactivation of 2-aminoanthracene (2AA), which was not stimulated by human b(5). All other main findings of the effect of rat b(5) were confirmed with human b(5), i.e. for CYP2A6: N-nitrosodiethylamine (NNdEA): approximately 14-fold increase ( approximately 23-fold with rat b(5)) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK): approximately 3-fold ( approximately 9-fold with rat b(5)); for CYP2E1: NNdEA: approximately 1.5-fold increase ( approximately 3-fold with rat b(5)); NNK: no mutagenicity with or without human b(5). Both CYP2A6 and CYP2E1 demonstrated total dependence on the presence of human b(5) for N-nitrosodi-n-propylamine (NNdPA) mutagenicity, as was shown before with rat b(5).

Comparative Study↗

PubMed1987

Decreased bioactivity of circulating prolactin in patients with rheumatoid arthritis.

Growth hormone and prolactin (PRL) were measured by radio-immunoassay in sera of 36 patients with rheumatoid arthritis (24 females and 12 males) and of 50 normal blood donors (25 males and 25 females). The bioactivity of PRL was also determined for both groups, using the Nb2 rat lymphoma proliferation assay. Although no significant difference was found between serum PRL values of patients and controls when determined by radio-immunoassay, the bioactivity of PRL was significantly decreased in patients' sera, when compared to values obtained in age and sex-matched controls. This decreased PRL bioactivity could not be attributed to drug treatments administered to the patients examined.

Arthritis, Rheumatoid↗

PubMed2000

Intranasal instillation of aflatoxin B(1) in rats: bioactivation in the nasal mucosa and neuronal transport to the olfactory bulb.

Aflatoxin B(1) (AFB(1)) may be present in moldy dust. Inhalation of contaminated dust particles may result in high local exposure of the nasal mucosa. The present study was designed to assess bioactivation and toxicity of AFB(1) in the nasal mucosa after intranasal administration of the mycotoxin in rats and also to examine if translocation of the mycotoxin occurs from the nasal mucosa to the brain along olfactory neurons. Female Sprague-Dawley rats were given (3)H-AFB(1) (0.2, 1 or 20 microg) intranasally and were sacrificed at various intervals (1 h to 20 d). Tissues were examined autoradiographically or histopathologically. Quantitative data were obtained by beta-spectrometry in rats given (3)H-AFB(1) intranasally or orally (for comparison). The data indicated that intranasal administration of AFB(1) resulted in formation of tissue-bound metabolites in sustentacular cells, in some cells of Bowman's glands, and in a population of neuronal cells in the olfactory mucosa, whereas in the respiratory nasal mucosa, there was selective bioactivation of AFB(1) in mucous cells. Intranasal instillation of 20 microg AFB(1) resulted in disorganized undulating olfactory epithelium, with injured neuronal and sustentacular cells. In the respiratory epithelium, there was selective destruction of mucous cells. beta-Spectrometry and autoradiography with tape-sections of the head of rats given (3)H-AFB(1) intranasally indicated transport of AFB(1) and/or AFB(1) metabolites along the axons of the primary olfactory neurons to their terminations in the glomeruli of the olfactory bulb. The data indicate that the materials transported in the olfactory nerves represent AFB(1) and/or some of its nonreactive metabolites. It is concluded that application of AFB(1) on the nasal mucosa in rats results in high local bioactivation of the mycotoxin in this tissue and translocation of AFB(1) and/or its metabolites to the olfactory bulb.

Administration, Intranasal↗

PubMed2001

Strain-related differences in bioactivation of vinyl carbamate and formation of DNA adducts in lungs of A/J, CD-1, and C57BL/6 mice.

Inbred strains of mice exhibit differing susceptibilities to formation of lung tumors induced by procarcinogens including ethyl carbamate (EC) and vinyl carbamate (VC). Strain A/J mice are susceptible, whereas C57BL/6 mice are resistant to lung tumor development. In this study, we tested the hypothesis that differential susceptibilities of A/J, CD-1, and C57BL/6 mice to lung tumor development are associated, in part, with their capacities for VC bioactivation and with the extents of DNA adduct formation. Previous studies have shown that the P450 isozyme CYP2E1 and microsomal carboxylesterases are involved in activation and detoxication of VC, respectively. Bioactivation capacity, as estimated by ratios of p-nitrophenol hydroxylase, a CYP2E1 catalytic marker, to carboxylesterase activities, was greater in control A/J (1.32 +/- 0.18 x 10(-6)) and CD-1 (1.25 +/- 0.29 x 10(-6)) mice than in control C57BL/6 (0.69 +/- 0.12 x 10(-6)) mice. The ratios were reduced in all three strains of mice treated with VC. Covalent binding of [(14)C-carbonyl]-VC to lung proteins was time- and dose-dependent, and was significantly higher in A/J and CD-1 mice than in C57BL/6 mice. Experiments using (32)P-postlabeling/thin-layer chromatography showed formation of the DNA adducts 1,N:(6)-ethenodeoxyadenosine and 3,N:(4)-ethenodeoxycytidine in lungs of mice treated with VC. The DNA adducts were detected at 30 min after treatment, peaked at 60 min, and declined thereafter. Levels of 1,N:(6)-ethenodeoxyadenosine and 3,N:(4)-ethenodeoxycytidine were about 70% higher in A/J and CD-1 mice than in C57BL/6 mice. These results indicated that formation of VC metabolites in these murine strains is linked to their bioactivation capacities, and suggested that this attribute may confer differing susceptibilities to lung tumor development.

Animals↗

PubMed2005

Effects of co-medicated drugs on cyclophosphamide bioactivation in human liver microsomes.

The alkylating agent cyclophosphamide (CP) is a prodrug requiring cytochrome P-450-mediated bioactivation to form the active 4-hydroxycyclophosphamide (4OHCP). Modifications in the rate of CP bioactivation may have implications for the effectiveness of CP therapy, especially in high-dose regimens. In this study, agents frequently co-administered with CP in high-dose chemotherapy regimens were tested for their possible inhibition of the bioactivation of CP in human liver microsomes. The Km and Vmax values for the conversion of CP to 4OHCP were 93 microM and 4.3 nmol/h.mg, respectively. No inhibition was observed for aciclovir, carboplatin, ciprofloxacine, granisetron, mesna, metoclopramide, ranitidine, roxitromycin and temazepam. Inhibition was observed for amphotericin B, dexamethasone, fluconazole, itraconazole, lorazepam, ondansetron and thiotepa, with IC50 values of 50, >100, >50, 5, 15, >100 and 1.25 microM, respectively. For all but thiotepa, these IC50 values were higher than the therapeutic drug levels and thus considered of no clinical relevance. We conclude that of the tested co-medicated agents, only thiotepa inhibited metabolism of CP to 4OHCP at clinically relevant concentrations, and may thereby influence therapeutic and toxic responses of CP therapy.

Antifungal Agents↗

PubMed2002

Clinical results of single-level posterior lumbar interbody fusion using the Brantigan I/F carbon cage filled with a mixture of local morselized bone and bioactive ceramic granules.

STUDY DESIGN: A retrospective study to evaluate the results of single-level posterior lumbar interbody fusion (PLIF) using the Brantigan I/F cage (DePuy AcroMed Corp., Raynham, MA) filled with a mixture of local morselized autologous bone and bioactive ceramic granules. OBJECTIVES: To report the clinical and radiologic results of PLIF using the Brantigan I/F cage for lumbar degenerative pathologies with instability. SUMMARY OF BACKGROUND DATA: The Brantigan I/F cage for PLIF was designed to improve the fusion success of interbody fusion by separating the mechanical and biologic functions of PLIF using an implant device and autologous bone from the iliac crest. Although high fusion rates have been reported, donor site morbidity caused by bone harvest from the iliac crest remains a concern. The possibility of accomplishing cage PLIF using a mixture of local morselized bone and a bone extender was studied. METHODS: A total of 25 patients underwent single-level PLIF using the Brantigan I/F cage filled with a mixture of local morselized bone and bioactive ceramic granules. All patients were observed for more than 2 years (average 2 years 7 months) and evaluated by clinical rating and radiograph. RESULTS: Preoperative Japanese Orthopedic Association clinical scores were significantly improved in all patients at the time of follow-up. The average improvement rate was 83.1%. There were no serious complications. Minor complications included two dural tears and two cases of thrombophlebitis. No patient required blood transfusion. All patients achieved radiographic fusion and radiographic stability, although two patients fused in a collapsed position. Regional alignment of the operated segments was restored at surgery and maintained at the time of final follow-up. There were statistical improvements in percent slip and percent posterior disc height in patients with spondylolisthesis. CONCLUSIONS: Posterior lumbar interbody fusion using the Brantigan I/F cage with a mixture of local morselized bone and bioactive ceramic granules can yield a solid union with satisfactory regional alignment and adequate disc height without harvest of iliac crest bone.

Adult↗

PubMed1997

Osteoconductive properties and efficacy of resorbable bioactive glass as a bone-grafting material.

The height of the available bone between the alveolar ridge and the sinus is often insufficient for placing endosseous implants in the posterior maxilla. Subantral augmentation after sinus elevation can be performed using bone-grafting materials such as autogenous bone, allografts, and alloplasts. The properties and performance of a recently developed resorbable bioactive glass (BioGran) were investigated with regard to bioactivity and bone-forming capability. The bioactive glass was grafted into the sinus cavities of 25 patients and biopsies were taken after 7 months. The samples were examined by conventional histologic techniques, elemental composition and distribution assayed by an electron probe microanalyzer, and comparative biomechanical data for BioGran and bone tissue gathered. Histologic and biomechanical examination indicated bone formation in all cases, with biomechanical properties of the regenerated bone close to those of bone tissue. The results of this study suggest that BioGran exhibits osteoconductive properties and efficacy as an alloplastic bone-grafting material.

Biocompatible Materials↗