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PubMed1995

In vitro maturation of equine oocytes obtained from different age groups of sexually mature mares.

Oocytes were harvested from mare ovaries obtained at slaughter and were divided into 3 groups based on the age of the donor. The age groups consisted of young (2 to 7 yr), middle-aged (8 to 14 yr) and aged (>or=15 yr) mares. There were no differences between age groups in the proportions of follicles available for examination or the proportions of normal, abnormal or total oocytes collected. After 24 h of culture, the overall maturation rate to the second metaphase (MII) was 52.7%. Maturation rates for oocytes obtained from young and middle-aged mares were similar, but oocytes from aged mares were only approximately 25% as likely to reach MII and they were 3 times more likely to remain at metaphase I. Twelve oocytes had chromosome spreads suitable for counting; 6 were haploid, 2 were hyperhaploid and 4 were hypohaploid. Insufficient numbers of readable spreads precluded comparisons of chromosome complements between age groups.

Journal Article↗
PubMed2006

In vitro effects of insulin-like growth factors and insulin on oocyte maturation and maturation-inducing steroid production in ovarian follicles of common carp, Cyprinus carpio.

In vitro germinal vesicle breakdown (GVBD) in Cyprinus carpio oocytes was induced by recombinant human insulin-like growth factor-I and -II (IGF-I and IGF-II) and bovine insulin (b-insulin). Treatment of postvitellogenic ovarian follicles with IGF-I and b-insulin increased concentration of maturation-inducing hormone (MIH), 17alpha,20beta-dihydroxy-4-pregnane-3-one (DHP) in the medium. IGF-I and IGF-II both and b-insulin induced GVBD in denuded oocytes. IGF-I analogue R3 IGF-I was more potent than IGF-I in inducing GVBD of postvitellogenic follicles suggesting that ovarian IGF binding proteins may inhibit IGF-I action. Vitellogenic follicles, which were immature for oocytes to complete GVBD in response to DHP or HCG, underwent GVBD by IGF-I, not by b-insulin. IGF-I was also able to stimulate DHP production in such follicles. Addition of DHP and HCG to the culture of vitellogenic follicles containing IGF-I or b-insulin did neither potentiate the stimulation of GVBD induced by IGF-I nor initiate the same in response to b-insulin. Incubation of postvitellogenic follicles with trilostane (3beta-HSD inhibitor) had no inhibitory effects on IGF-I- and b-insulin-induced GVBD but attenuated the same under HCG stimulation. Trilostane, however, strongly inhibited DHP production induced by all these effectors. Induction of GVBD by IGF-I and b-insulin was not altered in the presence of actinomycin D. However, it significantly blocked the HCG-induced GVBD. Cycloheximide was shown to inhibit the induction of GVBD and DHP production by IGF-I, b-insulin and HCG. Both actinomycin D and cycloheximide were found to inhibit DHP production stimulated by all the three effectors. Collectively, these observations indicate that IGF-I and b-insulin can induce GVBD via MIH- and transcription-independent pathway. Incubation of the follicles with gap junction uncouplers, 1-heptanol or 1-octanol, had no effect on IGF-I- and b-insulin-induced GVBD, but attenuated the same induced by HCG. These uncouplers, however, inhibited DHP production induced by IGF-I, b-insulin and HCG. This result suggests that both IGF-I and b-insulin can induce oocyte maturation without coupled gap junction between oocytes and granulosa cells, while homologous gap junctions are required for DHP production. Inhibitors of phosphatidylinositol-3 kinase (PI-3 kinase), wortmannin and LY294002 inhibited GVBD by IGF-I and b-insulin. These two inhibitors also attenuated HCG-induced GVBD. These data suggest that PI-3 kinase activity is required for IGF-I, b-insulin and HCG induction of GVBD in C. carpio.

Androstadienes↗
PubMed2005

Exposure to chemokines during maturation modulates antigen presenting cell function of mature macrophages.

Macrophages generated with macrophage-colony stimulating factor (M-CSF) are defective in antigen presenting cell (APC) function, although they do express major histocompatibility (MHC) class II molecules, numerous accessory molecules, and intercellular adhesion molecules. In the present study, we show evidence that the acquisition of APC function is influenced significantly by microenvironmental condition of development. Macrophages generated from bone marrow progenitor cells with M-CSF and interleukin (IL)-6 were defective in APC function as determined by their ability to induce anti-CD3 monoclonal antibody (mAb)-primed T cell proliferation. Macrophages generated in the presence of some of the CC chemokines such as leukotactin-1, macrophage inflammatory protein (MIP)-1alpha, and RANTES together with M-CSF and IL-6, however, induced proliferation of anti-CD3 mAb-primed T cells. Maximum level of APC function was obtained when developing macrophages were exposed with the chemokines at the late stage of maturation. Enhanced APC function of the macrophages appeared to be correlated with the expression of co-stimulatory molecules and the ability to produce cytokines. These results suggest that the acquisition of APC function of mature macrophage is modulated significantly by the microenvironmental condition during development.

Animals↗
PubMed1991

Marketing to the mature population, Part 1: Evaluating the attractiveness of the mature population.

The mature population represents a major market force for the 1990s and the 21st century. Individuals age 65 and older make up a sizable percentage of the population and spend billions of dollars on health-related products and services. Despite the size and apparent attractiveness of this market, it may not be an easy one to penetrate. Pharmacists must recognize the vast differences within this group in terms of what its members want and expect from pharmacies. Only by understanding the unique attributes of the specific subgroups can pharmacists develop an effective marketing plan to serve their needs profitably. Specific marketing techniques for attracting segments of the mature population are described in Part 2.

Aged↗
PubMed2006

The Escherichia coli cytochrome c maturation (Ccm) apparatus can mature cytochromes with an extra cysteine within or adjacent to the CXXCH motif.

c-Type cytochromes are characterized by covalent attachment of haem to protein through thioether bonds between the vinyl groups of the haem and the thiols of a Cys-Xaa-Xaa-Cys-His motif. Proteins of this type play crucial roles in the biochemistry of the nitrogen cycle. Many Gram-negative bacteria use the Ccm (cytochrome c maturation) proteins for the post-translational haem attachment to their c-type cytochromes. The Ccm system can correctly mature c-type cytochromes with CCXXCH, CCXCH, CXCCH and CXXCHC motifs, even though these are not found naturally and the extra cysteine might, in principle, disrupt the biogenesis proteins. The non-occurrence of these motifs probably relates to the destructive chemistry that can occur if a free thiol reacts with haem iron to generate a radical.

Amino Acid Motifs↗
PubMedDate not supplied

Maturation-related changes in distribution of lectin receptors in baboon (Papio anubis) spermatozoa during epididymal maturation.

Changes in distribution of surface glycoproteins in baboon sperm were studied by lectin blotting techniques. In baboon, several changes in sperm surface occur during epididymal passage. These changes include increased staining of band that was observed with the WGA binding glycoproteins of 140, 80, 52, and 46 kDa; Con A bands of 66, 37, and 26 kDa; and the PNA binding glycoprotein of 114 kDa. A second change was the loss of preexisting band that was observed with RCA binding glycoproteins of 120, 80, 58, 53, 46, and 37 kDa; and the Con A band of 80 kDa. A final change was noted with Con A binding in which six bands of 8, 9, 12, 14, 18, and 21 kDa were added as the sperm matured through the cauda epididymis. These findings present new information on the changes in distribution of surface glycoproteins in baboon sperm during epididymal passage. There was some reorganization of the molecular structure of the sperm during epididymal maturation.

Animals↗
PubMed1994

Maturation in Douglas-fir: II. Maturation characteristics of genetically matched Douglas-fir seedlings, rooted cuttings and tissue culture plantlets during and after 5 years of field growth.

Seedlings, rooted cuttings from juvenile stock plants, and cotyledon-derived tissue culture plantlets were propagated from several coastal Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) full-sib families so that the rooted cuttings and plantlets were clonally identical. The stock types (seedlings, rooted cuttings and plantlets) were planted in the field in spring 1987. In fall 1991, after five complete growing seasons, the plants were measured and these values compared to maturation "markers" identified for Douglas-fir in the companion paper (Ritchie and Keeley 1994). Nodal branch lengths and nodal branch diameters decreased in the order seedlings > rooted cuttings > plantlets. The decreases were about 21% for nodal branch lengths and 24% for nodal branch diameters. Seedlings carried significantly more total branches (nodal + internodal) than the other two stock types. Height growth was similar for the three stock types, but plantlet height increment was beginning to decrease during the fourth year. We conclude that vegetative propagules of Douglas-fir exhibited traits of mature trees. These were particularly marked in the cotyledon-derived plantlets.

Journal Article↗
PubMed1980

Head maturation pathway of bacteriophages T4 and T2. V. Maturable epsilon-particle accumulating an acridine-treated bacteriophage T4-infected cells.

A maturable head-related particle of bacteriophage T4 has been identified and characterized. This epsilon-particle has the same size as the prehead, but its shell is made of the cleaved product of gene 23 (gp23*). It contains internal matter, most likely the processed core proteins, which is lost or modified by experimental manipulations. It accumulates, together with partially filled ("grizzled") heads, in T4 infected cells that are treated with 9-aminoacridine. On sections of "well-preserved" cells the epsilon-particles are not identifiable with certainty; a more or less empty breakdown product of them becomes visible when cytoplasmic leakage is induced. The number of particles per cell is then in agreement with the biochemically and with the number of particles counted in lysates. Morphologically and biochemically, the isolated epsilon-particles closely resemble the empty small particles of 17- -infected cells described in previous papers of this series. Both are composed of gp23* and are still unexpanded, so that they are not yet able to bind the minor head proteins soc and hoc. We discuss the possibility of the epsilon-particle being an intermediate on the normal T4 wild-type head maturation pathway.

Aminacrine↗
PubMed2002

Phenotypes and phosphatidylinositol glycan-class A gene abnormalities during cell differentiation and maturation from precursor cells to mature granulocytes in patients with paroxysmal nocturnal hemoglobinuria.

To define the phosphatidylinositol glycan-class A (PIG-A) gene abnormality in precursor cells and the changes of expression of glycosylphosphatidylinositol-anchored protein and contribution of paroxysmal nocturnal hemoglobinuria (PNH) clones with PIG-A gene abnormalities among various cell lineages during differentiation and maturation, we investigated CD59 expression on bone marrow CD34(+) cells and peripheral granulocytes from 3 patients with PNH and the PIG-A gene abnormalities in the CD59(-), CD59(+/-), and CD59(+) populations by nucleotide sequence analyses. We also performed clonogeneic assays of CD34(+)CD59(+) and CD34(+)CD59(-) cells from 2 of the patients and examined the PIG-A gene abnormalities in the cultured cells. In case 1, the CD34(+) cells and granulocytes consisted of CD59(-) and CD59(+) populations and CD59(-), CD59(+/-), and CD59(+) populations, respectively. Sequence analyses indicated that mutation 1-2 was in the CD59(+/-) granulocyte population (20 of 20) and the CD34(+)CD59(-) population (2 of 38). In cases 2 and 3, the CD34(+) cells and granulocytes consisted of CD59(+) and CD59(-) cells. Sequence analyses in case 3 showed that mutation 3-2 was not in CD34(+)CD59(-) cells and was present in the CD59(-) granulocyte population. However, PIG-A gene analysis of cultured CD34(+)CD59(-) cells showed that they had the mutation. This analysis also revealed that there were some other mutations, which were not found in CD34(+)CD59(-) cells and CD59(-) or CD59(+/-) granulocytes in vivo, and that sometimes they were distributed specifically among different cell lineages. In conclusion, our findings suggest that PNH clones might contribute qualitatively and quantitatively differentially to specific blood cell lineages during differentiation and maturation of hematopoietic stem cells.

Aged↗
PubMed1996

Influence of realimentation of mature cows on maturity, color, collagen solubility, and sensory characteristics.

Cull beef cows (n = 80) that had consumed similar grassland diets were assigned to one of four feeding periods (0, 28, 56, and 84 d) and subdivided into two groups fed either a high-energy, high-protein diet or a high-energy, low-protein diet. Treatments were designed to examine the effect of time on feed, dietary protein, and electrical stimulation on carcass traits, composition, shear force, sensory profile, collagen characteristics, and myoglobin state. Within 1 h of slaughter, the right side of each carcass was electrically stimulated, and the left side served as the control. The only trait influenced by protein level was longissimus muscle area, for which a high-protein diet resulted in larger (P < .05) longissimus muscle areas. Increased time on a high-energy diet increased USDA yield grade and sensory ratings; however, metmyoglobin and reduced myoglobin values decreased between 0 and 28 d on feed. Electrical stimulation improved lean color, shear force values, and sensory attributes. Electrical stimulation decreased shear force by 2.8 kg for 0-d carcasses. With subsequent days on feed, shear force values continued to decrease, but this effect was minimal in electrically stimulated carcasses. However, protein level did not significantly influence palatability and quality attributes. The greatest (P < .05) improvement in marbling score was observed in electrically stimulated carcasses from cows fed for 84 d. Additionally, feeding a high-protein diet for 84 d resulted in a slightly lower maturity score. Even though values for palatability and quality traits were improved by antemortem and postmortem treatments, the magnitude of improvement may not be great enough for steaks from mature fed cows to be considered as acceptable as steaks from young fed beef.

Aging↗
PubMed2000

Identification of maturation-inducing steroid in a freshwater perch Anabas testudineus and differential responses of intact follicles and denuded oocytes to cyclic AMP in oocyte maturation.

Postvitellogenic follicles of freshwater perch Anabas testudineus incubated with [(3)H]pregnenolone as exogenous precursor produced several metabolites, including 17 alpha, 20 beta-dihydroxy-4-pregnen-3-one (DHP) and 5 beta-pregnane-3 alpha, 17 alpha,20 beta-triol (5 beta-3 alpha,17 alpha,20 beta-P). These were identified by chromatography, microchemical reactions, and crystallization to constant specific activity. Following stimulation with fish (perch) pituitary extract (FPE) there was significant high production of DHP and 5 beta-3 alpha,17 alpha,20 beta-P, concomitant with a high percentage of germinal vesicle breakdown (GVBD). Inhibitor of steroidogenesis (trilostane) and inhibitors of protein synthesis (cycloheximide and actinomycin-D) completely blocked FPE-induced pregnenolone metabolism and oocyte maturation. The effectiveness of various C(21) steroids in inducing GVBD was examined. Results indicate that DHP was the most potent inducer of GVBD than other structurally related C(21) steroids. In intact follicles, FPE-stimulated production of DHP was shown to be mediated through the adenylate cyclase-cAMP pathway. Addition of IBMX or forskolin, which increases the endogenous cAMP level, as well as directly supplementing dbcAMP to the incubation medium, had no inhibitory effect on DHP-induced GVBD in the intact follicles. But all these agents were shown to inhibit GVBD in fully denuded oocytes. This study provides evidence that DHP, produced by postvitellogenic follicles through the adenylate cyclase-cAMP pathway, is the maturation-inducing steroid in freshwater perch and that the role played by cAMP in the induction of GVBD in intact follicles is different from that in the denuded oocytes. J. Exp. Zool. 287:294-303, 2000.

1-Methyl-3-isobutylxanthine↗
PubMed1992

Alteration of folate analogue transport inward after induced maturation of HL-60 leukemia cells. Molecular properties of the transporter in an overproducing variant and evidence for down-regulation of its synthesis in maturating cells.

Studies are described examining further the decline in folate analogue influx mediated by the one-carbon reduced-folate transport system in HL-60 cells following induction of maturation by cytodifferentiation agents. To facilitate the investigation of the underlying basis of this phenomenon, we derived a variant (HL-60/LCV) with 4-5-fold elevated influx capacity (Vmax) for folate analogues. A commensurate increase in the putative transporter for this system was documented by affinity labeling of these cells with N-hydroxysuccinimide-[3H]aminopterin. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the affinity labeled plasma membrane in HL-60/LCV cells delineated a protein peak at Mr = 75,000-80,000. This was substantially greater than the analogous transporter (Mr = 45,000-47,000) we had delineated (Yang, C.-H., Sirotnak, F.M., and Mines, L.S. (1988) J. Biol. Chem. 263, 9703-9709) with the same methodology in the L1210 cell plasma membrane. In addition, the rate of translocation of the Mr = 75,000-80,000 transporter in HL-60 and HL-60/LCV cells was 2-fold lower than the rate of translocation determined for the Mr = 45,000-47,000 transporter in L1210 cells. During induced maturation of HL-60/LCV cells toward the granulocyte pathway, [3H]methotrexate (MTX) influx capacity and the amount of the affinity labeled transporter decreased rapidly in a parallel fashion. The decrease in [3H]MTX influx and in affinity labeling and in the amount of the Mr = 75,000-80,000 transporter was 5-fold following exposure to 210 mM dimethyl sulfoxide (Me2SO) for 5 days during growth in culture. Moreover, during cycloheximide treatment, the decay in [3H]MTX influx at 37 degrees C and in amount of affinity labeled transporter was the same (t1/2 = 144-155 min) for both control and Me2SO-treated HL-60/LCV cells. These results, which reveal no difference in metabolic turnover for control and Me2SO-treated cells, suggest that the decline in folate analogue influx in HL-60/LCV influx cells is a very early event in the program of differentiation and probably occurs by down-regulation of synthesis of the transporter for the one-carbon reduced-folate transport system.

Affinity Labels↗
PubMed1979

Maturation of bursal stem cells within allogeneic or syngeneic bursal microenvironment: acquisition of postbursal maturity.

Differentiation of bursal stem cells in an allogeneic or syngeneic bursal microenvironment was compared. Bursal stem cells were transplanted into CY-treated 4-day-old recipients and permitted to differentiate in these hosts for 6 weeks. Their maturity degree was thereafter assessed by transplanting them into secondary recipients by using morphologic and functional criteria. As the secondary recipients 4-day-old CY-treated or CY-treated and surgically bursectomized chicks were used. The results obtained demonstrate that bursal stem cells develop to mature postbursal cells also within an allogeneic bursa. They also indicate that although the interaction of different lymphoid cells requires histocompatibility, the interaction between stromal cells in the bursa and lymphoid progenitors is not genetically restricted.

Animals↗
PubMed1985

An antibody binding to human neutrophils demonstrates antigenic heterogeneity detected early in myeloid maturation which correlates with functional heterogeneity of mature neutrophils.

An IgG1 mouse monoclonal antibody (31D8) labels a subpopulation of human peripheral neutrophils. Heterogeneous binding to granulocyte precursors is seen in the bone marrow as early as the myelocyte stage of maturation. 31D8 binding is not affected by the in vitro stimulation or incubation of neutrophils. We demonstrate that the cells which bind 31D8 strongly (31D8-bright) are the same cells which depolarize, reduce nitroblue tetrazolium, and migrate chemotactically when stimulated with the chemoattractant N-formylmethionylleucylphenylalanine. Treatment with cytochalasin B modulates functional activity so that all cells depolarize or reduce nitroblue tetrazolium in response to this chemoattractant, but the heterogeneous binding of 31D8 does not change. The stable binding of 31D8 at 37 degrees C and during activation permitted characterization of the functional capacity of the two populations. These results demonstrate neutrophil heterogeneity early in myeloid maturation and correlate antigenic with functional heterogeneity. 31D8 will make it possible to study the significance of neutrophil heterogeneity in a variety of clinical situations.

Antibody Specificity↗
PubMed1985

[Mechanisms regulating ovulation rate and oocyte maturation. Maturation induction and superovulation].

The follicular growth takes longer in most mammals than it does in rodents: (4 to 15 days between the antral stage and ovulation in rodents, versus 65 days in women). The ovulation rates typical of animal species are mainly regulated during two critical periods: antrum formation and a few days before ovulation. The FSH level appears to be determinant, but in the animal species or races whose ovulation rate is near one, a dominant follicle is involved in the atresia of others. Increasing the level of gonadotrophins, especially of FSH, results in superovulation. However, the results are often irregular, with prolonged maturations and ovulations and oocytes of uncertain quality. Using pituitary gonadotrophins instead of placental or urinary hormones considerably increases the number of oocytes available and improves the development of embryos if the FSH/LH ratio of pituitary gonadotrophins is adjusted to the species involved. Thus, the main problem concerns the quality of the oocyte. At the present time, no criterion allows a prediction of the quality of the oocyte, and the complexity of the mechanisms involved in its intrafollicular maturation do not foreshadow a simple and rapid solution. However, appreciable improvements in our techniques are possible on the basis of current knowledge.

Animals↗
PubMedDate not supplied

The prediction of fetal maturity: a comparison between the bubble stability test and cytological evaluation of maturity.

Amniotic fluid from fifty women soon to be delivered, or already in labour, was analysed in the Obstetric unit of University Teaching Hospital, Lusaka. A Bubble Stability Test (Clements et al, 1972) and cytological screening for maturity (Sharma & Trussell, 1970) was carried out on each specimen. The latter test has been routinely used in the Obstetric unit for three years. The intent was to discover which test was the most useful indicator of fetal maturity.

Amniotic Fluid↗
PubMed1983

Differentiation and maturation of thy-1 negative bone marrow cells. I. Effects of the thymus and radioresistant helper functions on the maturation of precursor cells specific for heterologous erythrocytes.

The effects of adult thymectomy (ATx) and preimmunization on the differentiation of cells responsible for delayed footpad reaction (DFR), plaque forming cells (PFC) and cell mediated lympholysis (CML) were examined in lethally irradiated and thy-1 negative bone marrow cell reconstituted C57BL/6 recipients. ATx reduced the degrees of immune responses in irradiated and reconstituted mice. When the recipients had been preimmunized, all of DFR, PFC and CML became detectable even in irradiated and reconstituted ATx mice. Preimmunization also evoked early maturation of precursor cells for CML. Therefore, it was suggested that radioresistant helper effects, presumably in the presence of antigens, could promote the differentiation and maturation of T cell precursors in bone marrow in the absence of the thymus. We also demonstrated differences in restoration periods of such responses after lethal irradiation and reconstitution. One or two weeks following irradiation and reconstitution, DFR was first detectable. On the other hand, the generation of PFC was detected later than 2 weeks after bone marrow cell reconstitution, and it took over 4 weeks for thy-1 negative bone marrow cells to raise CML. T cells responsible for DFR may have lower dependency on the thymus than those for PFC and CML.

Allergy and Immunology↗
PubMed1984

[Recent findings on follicle and oocyte maturation. 1. Development of follicles and maturation of follicles].

A review is given of the present knowledge of the development of follicles and oocytes, especially in the human. The first report deals with the course of development of follicles from the beginning in the fetal ovary to the mature Graafian follicle in the adult women. Questions of terminology, functional morphology and important aspects of the regulation of follicular growth are discussed. The last part of the paper summarizes the present day possibilities in monitoring growth and maturation of ovarian follicles in clinical practice.

Androstenedione↗