SEARCH · PubMed Health

Results for “Bioactivation”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 721 records · Page 40Linked to original sources

PubMed2003

Deproteinized bovine bone (Bio-Oss) and bioactive glass (Biogran) arrest bone formation when used as an adjunct to guided tissue regeneration (GTR): an experimental study in the rat.

OBJECTIVES: Grafting of deproteinized bovine bone or bioactive glass has been suggested as an adjunct to guided tissue regeneration (GTR) for the treatment of periodontal and peri-implant bone defects but the influence of these materials on bone formation is not clarified. The aim of the study was to examine the long-term influence of deproteinized bovine bone (Bio-Oss) or bioactive glass (Biogran) on bone formation produced by GTR. MATERIAL AND METHODS: Eighteen rats were used. Following incisions along the inferior border of the mandible, muscle-periosteal flaps were raised to expose the mandibular ramus. Rigid, hemispherical, Teflon capsules (6 mm internal diameter and 1 mm peripheral collar) loosely packed with a standardized quantity of either deproteinized bovine bone (test group 1) or bioactive glass (test group 2), or empty capsules (control group) were then placed with their open part facing the lateral surface of the ramus (one capsule per animal). After 1 year, the capsules were removed by a reentry operation, and the animals were sacrificed. Histological specimens of the augmented sites were prepared, and the volumes of (1). newly formed bone, (2). graft particles, and (3). soft connective tissue in the space originally created by the capsule were estimated by a point-counting technique in three to four histological sections, taken by uniformly random sampling. RESULTS: Limited bone formation was observed in the two test groups. The major part of the space originally created by the capsules was occupied by graft particles embedded in connective tissue. The mean volume of newly formed bone occupied only 23% of the total space in the animals grafted with Bio-Oss and 12.6% in those grafted with Biogran. In the control animals, however, 88.2% (p<0.01) of the space was filled with newly formed bone. There were no signs of ongoing bone formation in any of the three experimental groups. CONCLUSION: It is concluded that grafting of Bio-Oss or Biogran as an adjunct to GTR arrests bone formation.

Animals↗

PubMed1991

Bioactivity of skeletal muscle proteolysis-inducing factors in the plasma proteins from cancer patients with weight loss.

We determined the circulating level of bioactivity for skeletal muscle proteolysis-inducing factors (PIF) in the blood samples from cancer patients whose body weight loss was greater than 10%. The level of bioactivity was estimated by measurement of tyrosine release from isolated 1at diaphragm muscles incubated with an ultrafiltered fraction of plasma or serum proteins containing molecules from 0 to 25 kDa in molecular weight. Significant levels of bioactivity were detected in 25 of the 50 cancer samples. No activity was found in 18 of the samples from healthy human blood donors. The ability of 13 of the cancer samples to induce muscle proteolysis was significantly inhibited by incubation of muscles in presence of indomethacin (10 microM). The neutralisation of 12 of the cancer samples with the antibodies to recombinant human interleukin-1 (IL-1), alpha and beta forms, partially abrogated the activity in five samples. These results suggest that the accelerated breakdown of proteins induced by the cancer plasma factors is at least in part mediated by IL-1 in cooperation with other active factors not yet defined. Additionally, we have shown that the increased breakdown of proteins induced by PIF in the crude supernatant derived from activated mouse peritoneal macrophages is prevented by the treatment of muscles with either indomethacin or quin-2 (1 microM). These observations provide indirect evidence for a possible causal relationship between the production of PIF and the body-weight loss of cancer patients.

Adolescent↗

PubMed2005

Bioactive food stimulants of sympathetic activity: effect on 24-h energy expenditure and fat oxidation.

OBJECTIVE: Bioactive food ingredients influence energy balance by exerting weak thermogenic effects. We studied whether the thermogenic effect of a combination of capsaicin, green tea extract (catechins and caffeine), tyrosine, and calcium was maintained after 7-day treatment and whether local effects in the gastric mucosa were involved in the efficacy. DESIGN: The present study was designed as a 3-way crossover, randomised, placebo-controlled, double-blinded intervention. SETTING: Department of Human Nutrition, RVAU, Denmark. SUBJECTS: A total of 19 overweight to obese men (BMI: 28.0+/-2.7 kg/m2) were recruited by advertising locally. INTERVENTION: The subjects took the supplements for a period of 7 days. The supplements were administrated as a simple supplement with the bioactive ingredients, a similar enterocoated version, or placebo. In all, 24-h energy expenditure (EE), substrate oxidations, spontaneous physical activity (SPA), and heart rate were measured in respiration chambers on the seventh day of each test period. RESULTS: After adjustment for changes in body weight and SPA, 24-h EE was increased by 160 kJ/day (95% CI: 15-305) by the simple preparation as compared to placebo, whereas the enterocoated preparation had no such effect (53 kJ/day, -92 to 198); simple vs enterocoated versions (P=0.09). The simple preparation produced a deficit in 24-h energy balance of 193 kJ/day (49-338, P=0.03). Fat and carbohydrate oxidation were equally increased by the supplements. CONCLUSION: A supplement containing bioactive food ingredients increased daily EE by approximately 200 kJ or 2%, without raising the heart rate or any observed adverse effects. The lack of effect of the enterocoated preparation suggests that a local action of capsaicin in the gastric mucosa is a prerequisite for exerting the thermogenic effect.

Adult↗

PubMed2001

Bioactivity of [6R]-5-formyltetrahydrofolate, an unusual isomer, in humans and Enterococcus hirae, and cytochrome c oxidation of 10-formytetrahydrofolate to 10-formyldihydrofolate.

The bio-inactive C-6 isomer, [6R]-5-formyl-tetrahydrofolate (5-HCO-H(4)F), is not found in Nature. An oral dose of 13.5 micromol of [6R]-5-HCO-H(4)F in humans results in the appearance of the naturally occurring [6S]-5-methyl-tetrahydrofolate and relatively large amounts of other bioactive folates in plasma. The removal of the asymmetry at C-6 could account for these results. Two oxidized cytochrome c [cyt c (Fe3+)] molecules oxidize one 10-formyl-tetrahydrofolate (10-HCO-H(4)F) with second-order kinetics and a rate constant of 1.3 x 10(4) M(-1) x s(-1). The folate product of this oxidation reaction is 10-formyl-dihydrofolate (10-HCO-H(2)F), which has no C-6 asymmetric centre and is therefore bioactive. The folate-requiring bacterium, Enterococcus hirae, does not normally biosynthesize cytochromes but does so when given an exogenous source of haem (e.g. haemin). E. hirae grown in haemin-supplemented media for 3 days utilizes both [6R]- and [6S]-5-HCO-H(4)F in contrast to that grown in control medium, which utilizes only the [6S] isomer. Since known chemical reactions form 10-HCO-H(4)F from 5-HCO-H(4)F, the unusually large rate constant for the oxidation of 10-HCO-H(4)F by cyt c (Fe3+) may account for the unexpected bioactivity of [6R]-5-HCO-H(4)F in humans and in E. hirae grown in haemin-containing media. We used an unnatural C-6 folate isomer as a tool to reveal the possible in vivo oxidation of 10-HCO-H(4)F to 10-HCO-H(2)F; however, nothing precludes this oxidation from occurring in vivo with the natural C-6 isomer.

Cytochrome c Group↗

PubMed2002

Conformationally constrained human calcitonin (hCt) analogues reveal a critical role of sequence 17-21 for the oligomerization state and bioactivity of hCt.

Calcitonin (Ct) is a 32-residue peptide hormone that is mainly known for its hypocalcemic effect and the inhibition of bone resorption. Our previous studies have led to potent, side-chain lactam-bridged human Ct (hCt) analogues [Kapurniotu, A. Kayed, R., Taylor, J.W. & Voelter W. (1999) Eur. J. Biochem. 265, 606-618; Kapurniotu, A. & Taylor, J.W. (1995) J. Med. Chem. 38, 836-847]. We have hypothesized that a possibly type I beta turn/beta sheet conformation in the region 17-21 may play an important role in hCt bioactivity. To investigate this hypothesis, analogues of the potent hCt agonist cyclo17,21-[Asp17,Lys21]hCt (1) bearing type I (and II') or II beta turn-promoting substituents at positions 18 and 19 were designed, synthesized and their solution conformations, human Ct receptor binding affinities and in vivo hypocalcemic potencies were assessed. The novel analogues include cyclo17,21-[Asp17,D-Phe19, Lys21]hCt (2), cyclo17,21-[Asp17,Aib18,Lys21]hCt (3), cyclo17,21-[Asp17,D-Lys18,Lys21]hCt (4), corresponding partial sequence peptides containing the lactam-bridged region 16-22, and nonbridged control peptides. Only 1 showed a higher Ct receptor binding affinity than hCt, whereas analogues 2-4 had similar receptor affinities to hCt. In the in vivo hypocalcemic assay, 3 and 4 were as potent as 1, whereas 2 completely lost the high potency of 1, suggesting that type I (and II') beta turn-promoting substituents are fully compatible with in vivo bioactivity. CD spectroscopy showed that analogues 1-4 were markedly beta sheet-stabilized compared to hCt and indicated the presence of distinct beta turn conformeric populations in each of the analogues. Unexpectedly, the D-amino acid- or Aib-containing cyclic analogues 2-4 but not 1 or hCt self-associated into SDS denaturation-stable dimers. Our results demonstrate a crucial role of the conformational and topological features of the residues in sequence 17-21 and in particular of residues 18 and 19 for human Ct receptor binding and in vivo bioactivity and also for the self association state of hCt. These results may assist to delineate the structure-function relationships of hCt and to design novel hCt agonists for the treatment of osteoporosis and other bone-disorder-related diseases.

Amino Acid Sequence↗

PubMed2003

Starch in plasterboard sustains Streptomyces californicus growth and bioactivity of spores.

AIMS: The effects of plasterboard composition on Streptomyces californicus growth and bioactivity of spores were studied. METHODS AND RESULTS: Streptomyces californicus was grown on 13 modified plasterboards under saturated humidity conditions. The total content of fatty acid methyl esters was used for quantifying S. californicus biomass, while the spore-induced cytotoxicity and production of nitric oxide (NO), tumour necrosis factor-alpha, and interleukine-6 (IL-6) in mouse macrophages was used to assess the bioactivity of spores. Removal of starch completely from the plasterboard or only from the core reduced significantly the biomass production and the biological activity of spores in comparison with reference board. The biocide added into the core or on the liner decreased the growth markedly and inhibited the sporulation totally. The biomass production correlated positively with the spore number, cytotoxicity, and production of NO and IL-6. CONCLUSIONS: Streptomyces californicus grew under nutrient limitation on all studied plasterboards. The starch is the major factor enabling S. californicus to grow and to produce biologically active metabolites on plasterboard. SIGNIFICANCE AND IMPACT OF THE STUDY: The composition of building material has an impact on microbial growth and bioactivity of spores which may be involved in complex mechanisms leading to respiratory symptoms in the occupants in moisture damaged buildings.

Carbon↗

PubMed1999

In vitro and in vivo bioactivity of single-chain interleukin-12.

Interleukin-12 is a heterodimeric cytokine with potent immunoregulatory properties, making it a potential vaccine adjuvant and an immune response modulator. The study of its function is confounded by its heterodimeric structure. In order to facilitate the study of interleukin-12 in both in vitro and in vivo models, we constructed a single-chain porcine interleukin-12 gene and expressed the recombinant protein in Pichia pastoris. Single-chain porcine interleukin-12 was bioactive in vitro on both human and porcine cells as measured by its ability to induce proliferation of lymphoblasts and interferon-gamma secretion by lymph node cells. In contrast, the p40 subunit of porcine interleukin-12 alone did not induce proliferation or inhibit the activity of the single-chain porcine interkeukin-12. The in vivo bioactivity of single-chain porcine interleukin-12 was demonstrated in an oral immunization model where it increased antigen-specific IgA and IgG in jejunal mucus. These results indicate that binding of interleukin-12 to its receptor and transduction of intracellular signals requires both p40 and p35 subunits. The bioactivity of interleukin-12 expressed as a single polypeptide will facilitate its in vivo delivery and study of its structure and function.

Adjuvants, Immunologic↗

PubMedDate not supplied

[Lysophosphatidic acid: a "bioactive" phospholipid].

Lysophosphatidic acid (LPA) is a "bioactive" phospholipid able to generate growth factor-like activities in a wide variety of normal and malignant cell types. LPA is proposed to play an important role in normal physiological situations such as wound healing, vascular tone, vascular integrity, or reproduction. In parallel, LPA could also be involved in the etiology of some diseases such as atherosclerosis, cancer, or obesity. The bioactivity of LPA is mediated by the activation of specific G-protein coupled receptors (LPA1, LPA2, and LPA3) leading to the activation of a number of intracellular effectors. LPA is present in solution (bound to albumin) in various extracellular fluids (blood, ascites, aqueous humor), and is released in vitro by some cell types such as platelets, cancer cells, or adipocytes. LPA is a rather polar phospholipid, which cannot easily diffuse throughout plasma membrane, and its presence outside the cells requires soluble phospholipases (secreted phospholipase A2 and soluble lysophospholipase D/autotaxin), which synthesize LPA directly in the extracellular milieu, from precursors such as phosphatidic acid and lysophosphatidylcholine. In the future, LPA receptors, as well as the enzymes involved in LPA metabolism, will constitute promising pharmacological and transgenic targets to determine the physiopathological relevance of "bioactive" LPA in vivo.

Animals↗

PubMed2003

Improvements in GORE-TEX vascular graft performance by Carmeda BioActive surface heparin immobilization.

OBJECTIVES: a performance improvement in small-diameter bypass grafts remains a clinical objective. The purpose of the present investigation was to evaluate the potential of enhancing the thromboresistance of ePTFE grafts using a bioactive heparinized graft luminal surface in a canine model. MATERIAL AND METHODS: this study investigated the utility of heparin immobilization onto expanded polytetrafluoroethylene using Carmeda BioActive Surface technology (CBAS-ePTFE) as a means of improving vascular graft thromboresistance. Graft luminal surfaces were covered uniformly with the stably bound, end-point immobilized heparin. RESULTS: acute canine (5 greyhounds) interposition experiments comparing CBAS-ePTFE grafts to control ePTFE grafts showed that CBAS-ePTFE grafts remained patent and had significantly greater thrombus-free luminal surface (p<0.05). In a chronic canine (16 greyhounds) interposition experiment, significantly improved patency (p<0.05) was observed with CBAS-ePTFE grafts compared to controls. Long-term in vivo heparin bioactivity was demonstrated on CBAS-ePTFE grafts explanted between 1 and 12 weeks. On all CBAS-ePTFE grafts, heparin activity levels ranged from 15-25pmol/cm(2) and did not differ significantly (p>0.05). DISCUSSION: these results support the conclusion that a stable, CBAS-ePTFE surface provides improved thromboresistance and improved patency in canine interposition models. Maintenance of heparin catalytic activity on the graft surface in vivo likely contributes to this outcome and holds promise for the utility of this graft surface for clinical applications.

Analysis of Variance↗

PubMed2006

Homologous and heterologous carboxyl terminal peptide (CTP) linker sequences enhance the secretion of bioactive single-chain bovine LH analogs.

Single chain variants of the heterodimeric gonadotropins were engineered by tethering the genes of the individual subunits into one polypeptide. In tethered human (h) gonadotropins, the carboxyl terminal peptide (CTP) of the choriogonadotropin (CG) beta subunit serves as an effective linker to enhance the secretion of the analogs compared to variants lacking the CTP. The gonadotropin subunits of non-primate, non-equid species lack a CTP domain that precludes the use of a homologous CTP in tethered analogs in many species. Here we used the bovine LH as a model to examine the impact of the CTP domain of the hCGbeta subunit (denoted as huCTP) and of a previously untranslated CTP-like sequence decoded from the bovine LHbeta gene on the secretion and bioactivity of tethered analogs. This cryptic CTP (designated boCTP) was incorporated into the bovine LHbeta reading frame by deletion frame-shift mutations analogous to these that presumably occurred in primates and equids. We genetically engineered single chain variants in which the beta and alpha subunit domains were linked directly or via the heterologous huCTP or the homologous boCTP sequences and expressed them in CHO cells. The data suggest that the tethered analogs were expressed and N-glycosylated, but unlike the huCTP, the boCTP appears as devoid of mucin O-glycans. The incorporation of the boCTP or huCTP linkers enhanced by about 3fold the rate and efficiency of secretion from the transfected cells. The tether variants were bioactive, as estimated by induction of steroid production in immortalized granulosa cells expressing the rat LH receptor. Furthermore, the variants were about equally potent, as judged by their EC50s (0.7-0.9 ng/ml). Thus, the hCGbeta CTP maintains pro-secretory determinants without inhibiting receptor activation when applied as a linker in tethered bovine LH, implying that these CTP features are preserved when the domain is incorporated into non-primate single chain analogs. The study suggests that the boCTP and huCTP domains are advantageous for the secretion of tethered bovine gonadotropins, and also demonstrates strategies for the design of bioactive LH analogs in ruminant species.

Amino Acid Sequence↗

PubMed2006

Integrated in silico tools for exploiting the natural products' bioactivity.

Whereas computational methods for molecular design are well established in medicinal chemistry research, their application in the field of natural products is still not exhaustively explored. This article gives a short introduction into both the potential for the application of computer-assisted approaches, such as pharmacophore modelling, virtual screening, docking, and neural networking to efficiently access the bioactive metabolites, and the requirements and limitations related to this specific field. The challenge is which selection criteria and/or multiple filtering tools to apply for a target-oriented isolation of potentially bioactive secondary metabolites. Application examples are provided where in silico tools and classical methods used by natural product scientists are used in an effort to maximize their efficacy in drug discovery. Thus, integrated computer-assisted strategies may help to process the huge amount of available structural and biological information in a reasonably short time for a straightforward search of bioactive natural products.

Computer-Aided Design↗

PubMed1994

Existence of a rhamnogalacturonan II-like region in bioactive pectins from medicinal herbs.

Unusual component sugars such as 2-methylfucose (2-Me-Fuc), 2-methylxylose (2-Me-Xyl), apiose (Api), and aceric acid (AceA) are contained in the bioactive pectins from Bupleurum falcatum, Glycyrrhiza uralensis, and Angelica acutiloba, but not in the other bioactive pectic heteroglycans and arabinogalactans from Chinese and Japanese herbs tested. Each pectin was digested with endo-alpha-(1-->4)-polygalacturonase, and gave two enzyme-resistant fractions, PG-1 (rhamnogalacturonan core with neutral sugar side-chains) and PG-2, and an oligogalacturonide fraction (PG-3) by gel filtration on Bio-gel P-30. The PG-2 fractions commonly consisted of unusual sugars such as 2-Me-Fuc, 2-Me-Xyl, Api, AceA, 3-deoxy-D-lyxo-heptulosaric acid (Dha), and 3-deoxy-D-manno-2-octulosonic acid (Kdo) in addition to Rha, Fuc, Ara, Xyl, Man, Gal, Glc, GalA, and GlcA. Lithium degradation of each PG-2 gave a pentosyl-->6-deoxyhexosyl-->6-deoxyhexosyl-->pentitol fragment as a major oligosaccharide in addition to some neutral di- to trisaccharide alditols. Methylation analysis of the lithium degradation products from each PG-2 also indicated that these oligosaccharide alditols mainly consisted of terminal Rha, Araf, Fuc, Xyl, and Gal, 4-linked Rha, 3-linked Fuc, and 3'-linked Api. HPLC analysis showed that PG-2 had molecular heterogeneity. These results indicate that the bioactive pectins from medicinal herbs commonly consist of the minor KDO-containing region which resembles the rhamnogalacturonan II in plant cell walls.

Carbohydrate Sequence↗

PubMed1999

Inhibitory effect of luteolin 4'-O-glucoside from Kummerowia striata and other flavonoids on interleukin-5 bioactivity.

Interleukin (IL)-5 is a chemotactic factor of eosinophils, and promotes the growth and survival of eosinophils, which plays an important role in the eosinophilia-associated allergic inflammation. In this study, luteolin 4'-O-glucopyranoside was identified as the IL-5 inhibitor from Kummerowia striata Thunb. (Leguminosae) by activity-guided fractionation followed by structural analysis compared with reported spectral data. The flavone compound exhibited dose-dependent inhibitory effect on IL-5 bioactivity with 95% inhibition at 30 microM, 79% at 15 microM, 60% at 7.5 microM, 54% at 3.8 microM and 29% at 1.9 microM, where 50% of inhibition (IC50) value was shown at the concentration of 3.7 microM. Furthermore, the inhibitory effect on IL-5 bioactivity by other flavonoid compounds available was estimated. In view of the IC50 values, the inhibitory potency on IL-5 bioactivity was in order of luteolin 4'-O-glucopyranoside > cosmosiin (14.2 microM) approximately equal to apigenin (16.4 microM) approximately equal to luteolin (18.7 microM) > quercimeritrin (27.3 microM) approximately equal to kaempferol (30.0 microM).

Animals↗

PubMed1992

Bioactive and immunoactive prolactin levels after TRH-stimulation in the sera of normal women.

The availability of an improved microbioassay for lactogenic hormone measurement has enabled comparison of basal and dynamic prolactin bioactivity (BA) and immunoactivity (IRMA) in normal human serum. Serum from 16 normal females aged 22-74 years was assayed and revealed a mean BA/IRMA prolactin ratio of 1.6 for basal and 1.8 for peak TRH-stimulated levels. Basal prolactin levels in postmenopausal women measured by bioassay were lower than in premenopausal women showing a relative and absolute decrease in prolactin bioactivity with age, but there was no significant difference in dynamic levels. There was also no significant difference in BA or IRMA levels following the stress of venepuncture. These findings indicate that, as previously described for basal levels, there is a good correlation between dynamic prolactin bioactivity and immunoactivity in human serum.

Adult↗

PubMed1991

Serum bioactive and immunoreactive follicle stimulating hormone during chronic treatment with gonadotropin releasing hormone agonist in elderly men.

Chronic administration of GnRH agonists "down regulates" the pituitary and decreases LH and FSH serum levels. Changes in the bioactivity of FSH have not been adequately assessed under such treatment, for lack of a proper test. We examined serum changes under GnRH agonist treatment among 12 healthy elderly men suffering only from benign prostatic hypertrophy, for up to one year, using a modification of a granulosa cell bioassay for the determination of FSH bioactivity. While radioimmunoassay-FSH decreased, we noticed a significant increase in the bioactivity of this hormone. The clinical importance of this increase is discussed.

Aged↗

PubMed2000

Influence of bioactive glass on changes in alveolar process dimensions after exodontia.

BACKGROUND: Preservation of the alveolar process after tooth extraction is desirable because it facilitates placement of endosseous implants and minimizes adverse esthetic results associated with fixed partial dentures. The purpose of this study was to evaluate the clinical effectiveness of bioactive glass used as a graft material combined with calcium sulfate used in the form of a mechanical barrier in preserving alveolar ridges after tooth extraction. METHODS: Sixteen patients who required extraction of 2 anterior teeth or bicuspids participated in the study (split mouth design). After tooth extraction and elevation of a buccal full-thickness flap, experimental sockets were filled with bioactive glass, which in turn was covered with a layer of calcium sulfate. Control sites did not receive any graft or calcium sulfate. Titanium pins served as fixed reference points for measurements. No attempt was made to advance the flap to cover the socket areas on control or experimental sites (open socket approach). Reentry surgeries were performed at 6 months. RESULTS: Reentry surgeries showed that experimental sites presented with (1) significantly more internal socket bone fill (6.43 +/- 2.78 mm vs 4.00 +/- 2.33 mm on control sites), (2) less (although not statistically significantly less) resorption of alveolar bone height (0.38 +/- 3.18 mm vs 1.00 +/- 2. 25 mm on control sites), and (3) similar degree of horizontal resorption of the alveolar bony ridge as compared with controls (3. 48 +/- 2.68 mm vs 3.06 +/- 2.41 mm on control sites). CONCLUSIONS: This study suggests that treatment of extraction sockets with a combination of bioactive glass and calcium sulfate is of some benefit in preserving alveolar ridge dimensions after tooth extraction.

Adult↗

PubMed2002

Grafting mandibular third molar extraction sites: a comparison of bioactive glass to a nongrafted site.

OBJECTIVE: The purpose of this study was to evaluate the effectiveness of bioactive glass used as a graft material for regeneration of bone after the removal of impacted third molars. The healing distal to the second molars was followed, with documentation of the level of radiographic osseous fill and measurement of the changes in clinical attachment levels. METHODS: Fourteen (5 male and 9 female) patients completed the study at 1 year. After surgical removal of bilateral impacted third molars, one site was grafted with bioactive glass particles (BioGran, Orthovita, Malvern, Penn). The patients were followed up at 1 and 2 weeks after surgery for signs or symptoms of infection or any other complications that may have been related to the surgical procedures. At 3, 6, and 12 months, the clinical attachment levels distal to the second molars were assessed. At 6 and 12 months, radiographs were obtained to assess the amount of osseous fill distal to the second molars. RESULTS: A split-mouth design was used to test the efficacy of the grafting materials. Clinical attachment levels in the grafted sites were significantly higher than in the nongrafted sites. There was not a significant increase in bone formation when comparing the 2 sides at 1 year. CONCLUSION: This study suggests that treatment of third molar extraction sites with bioactive glass does significantly alter the clinical attachment level but not the level of osseous fill distal to the second molars after 1 year.

Adult↗

PubMed1996

ACTH-like bioactivity and immunoactivity in fetal lamb pituitaries at 0.65 and 0.95 gestation.

We wished to determine if the concentration of bioactive ACTH-like activity increased during development and if there was heterogeneity in ovine fetal anterior pituitary ACTH activity as measured by bioassay and radioimmunoassay (RIA). We obtained anterior pituitaries from eight sheep fetuses (four at 0.65 and four at 0.95 gestation; term 145 +/- 5 days) and extracted and homogenized them in ice-cold 5N acetic acid, 0.3% phenylmethanesulfonyl fluoride (PMSF) and 0.2% BSA. Fractionation of each pituitary extract was performed by size-exclusion chromatography using Sepadex G-50. The ACTH-like immunoactivity (ALI) profile for each pituitary showed two well-defined peaks. One eluted with human ACTH1-39 and the other eluted with the high molecular weight fraction in the void volume. Four fractions from the first peak representing the high molecular weight forms of ACTH activity and four fractions from the second peak representing the low molecular weight forms of ACTH activity were pooled separately. These two pools were subjected to reverse-phase chromatography (RPC) on a C-8 column using a linear gradient of 70% acetonitrile in 0.8% trifluoroacetic acid over a 60 min period. Based upon the RIA, the high molecular weight forms of ACTH from the G-50 column were resolved into three main fractions, one eluting similar to the standard ACTH1-39 and the remaining two eluting after that. The low molecular weight forms of ACTH from the G-50 column were resolved into three peaks, before, with, and after the standard. We used collagenase-dispersed rat adrenal cells to test the ACTH-like bioactivity (ALB) of the crude extracts and of the different fractions obtained from the RPC of the high and low molecular weight material. The concentration of ACTH-like bioactivity in the crude extracts was similar at the two stages of gestation. However, there was a trend for the low molecular weight peak to have more peptide eluting with human ACTH1-39 and higher ratios of ALB/ALI than did the high molecular weight peak. These results suggest that multiple ACTH molecular forms with different ALB/ALI ratios are present in the ovine fetal pituitary and that there is no selective increase in ACTH1-39 concentration in the fetal pituitary in late gestation.

Adrenocorticotropic Hormone↗