Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Maturation”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

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

At least 127 records · Page 7Linked to original sources
PubMed1988

Pubertal maturation and cognitive maturity in adolescents.

To determine the relationship between puberty and cognitive development, 135 students, ages 11 through 19 years, were studied. The participants were 73% white, 55% female, and of predominantly middle-class backgrounds with a mean Hollingshead score of 37.1 +/- 16.3. Measures of general intelligence (IQ), cognitive complexity (conceptual level), and cognitive style (perceptual field dependence-independence) were administered. Students rated their own level of sexual maturity (Tanner stage). Mean Tanner stage of 4.0 +/- 0.9 was consistent with the mean age of 14.2 +/- 2.2 years. General intelligence was average (105 +/- 18.2). Most did not demonstrate the use of mature cognitive processes, as reflected in low conceptual level scores (1.19 +/- 0.5) and a more field-dependent cognitive style (7.9 +/- 4.9). Older adolescents (r = 0.377; p less than 0.001), females (r = 0.217; p less than 0.005), and those with a higher IQ (r = 0.329; p less than 0.001) were cognitively more complex. Using an analysis of covariance to control for colinearity of variables, differences in conceptual level and cognitive style as functions of levels of sexual maturity were compared. Once the statistically significant colinear effects of age, gender, and IQ (p less than 0.0001) were removed, no statistical contribution was left attributable to the level of sexual maturity. In other words, when the effects of age were controlled, more advanced Tanner stage was not a predictor of more mature cognitive processes. Physical growth and development during puberty do not appear to affect cognitive development.

Adult↗
PubMed1987

Carp maturational-ovulatory gonadotropin but not carp vitellogenic gonadotropin or salmon maturational-ovulatory gonadotropin stimulates testosterone production by rat Leydig cells in vitro.

Carp (Cyprinus carpio) maturational-ovulatory gonadotropin, prepared from the fraction of pituitary extract adsorbed on Con A-Sepharose (Con A II) and subsequently adsorbed on CM-cellulose (Whatman CM-52), stimulated testosterone production by isolated rat Leydig cells. The fraction of carp pituitary extract unadsorbed on the immobilized lectin (Con A I) with a mol. wt of 30,000, which had previously been shown to contain vitellogenic gonadotropin, was devoid of steroidogenic activity. Salmon (Oncorhynchus keta) pituitary Con A I and Con A II fractions containing vitellogenic and maturational-ovulatory gonadotropin respectively did not enhance steroidogenesis in the same assay system. The results indicated that carp maturational-ovulatory gonadotropin resembled mammalian luteinizing hormone (LH) in its chromatographic behavior on Con A-Sepharose and CM-cellulose and also in its steroidogenic activity in rat Leydig cells. However, not all teleost maturational-ovulatory gonadotropins are LH-like: the salmon hormone is a notable exception. The data further supports the distinctiveness of carp vitellogenic gonadotropin and maturational-ovulatory gonadotropin.

Animals↗
PubMed1998

An endodermal sinus tumor arising from a mature cystic teratoma in the retroperitoneum in a child: is a mature teratoma a premalignant condition?

We herein report an 18-month-old girl who presented with a retroperitoneal mature teratoma that later developed into an endodermal sinus tumor. Her symptoms included an expanding abdominal girth. The serum levels of alpha-fetoprotein were moderately elevated. The excised specimen was a benign mature cystic retroperitoneal teratoma measuring 18 x 11 x 8 cm in size. A hemorrhagic focus measuring 4 cm in diameter was present, which proved to be the focus of an endodermal sinus tumor histologically. The retroperitoneal mature teratoma observed in this case showed malignant germ-cell differentiation. The above case is thought to be extremely rare, but these findings also suggest the possibility of a mature teratoma presenting as a premalignant condition. The sequence of "mature teratoma--germ-cell malignancy" is thus considered to represent a new potential pattern of early phase of carcinogenesis in teratomas.

Chorionic Gonadotropin↗
PubMed2002

A computer algorithm describing the process of vessel formation and maturation, and its use for predicting the effects of anti-angiogenic and anti-maturation therapy on vascular tumor growth.

We put forward an algorithm describing the three principal interconnected sub-processes that influence tumor and vasculature dynamics: (i) tumor cell proliferation (ii) angiogenesis, that is, the formation and regression of immature vessels (IV), and (iii) maturation, i.e., the formation and destabilization of mature vessels (MV). This algorithm takes account of the crucial quantitative interactions of these sub-processes, occurring across the molecular, cellular and organ levels. Implementing this complex algorithm in a computer model, one can evaluate the correlations between various factors influencing angiogenesis and their influence on tumor progression at any given moment. Moreover, the computer simulations enable analysis of the versatile effects of drugs on the growth and decay of both the tumor and the immature and mature blood vessels, as well as on the induction of an array of relevant growth factors such as angiopoietin-1 (Ang1), angiopoietin-2 (Ang2), vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF). Simulation results suggest that vessel maturation and destabilization of MV drive the otherwise non-linearly growing system into a very dynamic region, having irregular, scale-invariant, fluctuations, around certain asymptotic values of all the involved quantities. Destabilization itself adequately explains the experimentally observed eventual decrease of tumor growth, with no need to implicate additional assumptions, such as a new tumor growth inhibitory, or anti-angiogenic, factors. Our results further suggest that mono-therapy alone can slow tumor growth, but is not capable of eliminating it altogether. In contrast, the combined treatment of anti-angiogenic and anti-maturation drugs causes prolonged suppression of tumor growth and a significant linear decrease in average tumor size. Laboratory experiments are warranted for validating our predictions and for providing in vivo evaluated parameters.

Algorithms↗
PubMed1997

Morphological subtyping of acute myeloid leukemia with maturation (AML-M2): homogeneous pink-colored cytoplasm of mature neutrophils is most characteristic of AML-M2 with t(8;21).

Morphologic and cytochemical features of 30 acute myeloid leukemia subtype M2 (AML-M2) patients with t(8;21) were compared with those of 50 AML-M2 patients without t(8;21). It was disclosed that irregular nuclear shape, Auer bodies, and at least 90% myeloperoxidase positivity in blast cells, and pseudo-Pelger-Huët anomaly of the nuclei and homogeneous pink-colored cytoplasm of mature neutrophils were observed in 90-100% of the t(8;21)+ patients. The percentages of patients showing these features were significantly (P < 0.01) lower in the t(8;21)- group. Among these morphological features, homogeneous pink-colored cytoplasm of mature neutrophils is most characteristic of t(8;21)+ AML-M2, because it was seen in 90% of the t(8;21)+ patients but in only 2% of the t(8;21)- patients. Conversely, pale-colored cytoplasm without any granules in mature neutrophils or dyserythropoietic features was observed in 84% of the t(8;21)- patients, but in none of the t(8;21)+ patients. These data suggest that it is possible to subtype AML-M2 patients morphologically by the recognition of homogeneous pink-colored or pale-colored cytoplasm of mature neutrophils and dyserythropoietic features. Thus, the morphologic subtyping of AML-M2 can be utilized alone or in combination with chromosomal or molecular subtyping for biological and clinical studies of AML with maturation.

Adolescent↗
PubMedDate not supplied

Influence of maturation culture period on the development of canine oocytes after in vitro maturation and fertilization.

The objective of this study was to determine an optimum maturation period of canine oocytes for the development in vitro after in vitro fertilization (IVF). Canine oocytes larger than 110 micrometers in diameter, which were collected from ovaries at the follicular phase of the reproductive cycle, were cultured for each time (48, 72 and 96 h) in TCM 199 medium supplemented with 10% canine serum, fertilized, and then cultured in vitro for 8 days. Significantly more oocytes reached metaphase II (MII) in the 72-h culture group than in the 48-h culture group (25.6% vs. 41.0%). The percentages of oocytes that reached MII or beyond after maturation culture did not differ significantly between the 72- and 96-h culture groups, but the percentage of parthenogenetically activated oocytes in the 96-h culture group was significantly higher than that in the 72-h culture group. The percentages of cleaved embryos after IVF were significantly higher in the 48- and 72-h culture groups than in the 96-h culture group. In the 48-h culture group, 3.9% of fertilized oocytes developed to the 16-cell stage or beyond, but none of the cleaved embryos in the 72- and 96-h culture groups developed to the same stage. These results indicate that full nuclear maturation of oocytes collected from ovaries at the follicular phase occurs after 72 h of in vitro culture. However, an optimum maturation period (48 h) for the in vitro development of canine oocytes after IVF may be different from the period necessary to reach the maximal oocyte maturation rate, when based on the developmental stage of the cleaved embryos.

Animals↗
PubMed2004

The immunoglobulin family member dendrite arborization and synapse maturation 1 (Dasm1) controls excitatory synapse maturation.

In the developing mammalian brain, a large fraction of excitatory synapses initially contain only N-methyl-D-aspartate receptor and thus are "silent" at the resting membrane potential. As development progresses, synapses acquire alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPA-Rs). Although this maturation of excitatory synapses has been well characterized, the molecular basis for this developmental change is not known. Here, we report that dendrite arborization and synapse maturation 1 (Dasm1), an Ig superfamily member, controls excitatory synapse maturation. Dasm1 is localized at the excitatory synapses. Suppression of Dasm1 expression by using RNA interference or expression of dominant negative deletion mutants of Dasm1 in hippocampal neurons at late developmental stage specifically impairs AMPA-R-mediated, but not N-methyl-D-aspartate receptor-mediated, synaptic transmission. The ability of Dasm1 to regulate synaptic AMPA-Rs requires its intracellular C-terminal PDZ domain-binding motif, which interacts with two synaptic PDZ domain-containing proteins involved in spine/synapse maturation, Shank and S-SCAM. Moreover, expression of dominant negative deletion mutants of Dasm1 leads to more immature silent synapses. These results suggest that Dasm1, as a transmembrane molecule, likely provides a link to bridge extracellular signals and intracellular signaling complexes in controlling excitatory synapse maturation.

Animals↗
PubMed1998

Comparison between the natural postnatal maturation and the spermine-induced maturation of the rat intestine.

In the suckling rats, orally provided spermine induced structural and biochemical changes in the intestine, which are characteristics of the postnatal maturation. This induced maturation was compared to that occurring spontaneously. Eight mumol spermine were administered orally once a day, for one or three days, to suckling rats which were 11 days old at the beginning of the experiment. The animals were killed 0, 2, 4, 6, 8, 10 hours or 3 days after the first treatment. Control rats from the same litter were treated in the same way but received only the vehicle. In order to complete the study of the naturally occurring maturation, another group of rats was killed when they were 12, 13, 15, 16, 17, 18, 19, 20, 21 or 30 days old. Animal and intestine weights were measured. Disaccharidase specific activity, and protein, DNA and RNA contents were estimated in the small intestine. Histological and ultrastructural aspects of the intestinal mucosa were examined. For all these parameters, the maturation induced by spermine ingestion appeared close to that occurring naturally at weaning. Consequently, dietary spermine induces all the morphological and biochemical modifications characterizing the intestinal postnatal maturation in the suckling rat suggesting a role of the polyamines in the naturally occurring processes.

Animals↗
PubMed2005

Fertilization, cleavage and blastocyst development according to the maturation timing of oocytes in in vitro maturation cycles.

BACKGROUND: This study was to examine the developmental capacity of oocytes collected from an in vitro maturation (IVM) programme according to their maturation time. METHODS: The study included 47 IVM cycles that underwent blastocyst transfer. The patients (n = 38) were primed with 10 000 IU HCG 36 h before their oocyte retrieval. The oocytes were classified into three groups: group 1 (n = 139) where oocytes were matured on day of oocyte collection; group 2 (n = 627) where oocytes were matured on day 1 after IVM; group 3 (n = 163) where oocytes matured on day 2 after IVM. Fertilization, cleavage and blastocyst formation were compared between three groups. RESULTS: Rates of cleavage and blastocyst development in group 3 (72.2%, 96/133; 19.0%, 15/133) were significantly lower than those of group 1 (100%, 108/108; 58.3%, 63/108) and group 2 (91.5%, 487/532; 50.4%, 268/532) respectively (P < 0.01). The number of freezable good quality blastocysts among blastocysts developed from group 1 (52.4%, 33/63) was significantly higher than those from group 2 (35.4%, 95/268) and group 3 (6.7%, 1/15) (P < 0.01). There were 24 clinical pregnancies (51.1%, 24/47) after transfer of the blastocysts and 29 healthy babies were delivered. CONCLUSION: These results suggest that oocytes reaching metaphase II faster in an IVM programme have better embryonic developmental competence.

Adult↗
PubMed2001

Involvement of ethylene in the maturation of black spruce embryogenic cell lines with different maturation capacities.

To examine the possible relationship between ethylene and the capacity of embryogenic cell lines to produce mature somatic embryos of black spruce (Picea mariana (Mill.) B.S.P.), two embryogenic cell lines which exhibit different maturation capacities were used to analyse ethylene biosynthesis and that of its immediate precursor, 1-aminocyclopropane-1- carboxylic acid (ACC). Several compounds known to alter ethylene metabolism were also evaluated for their effect on the number of mature somatic embryos produced. The results showed that in the high capacity cell line, ethylene production and endogenous ACC pools were less than in the low capacity cell line. It was also demonstrated that limiting ethylene biosynthesis by adding inhibitors of ethylene biosynthesis or its physiological action to the maturation medium promoted somatic embryo production for the low capacity cell line. Conversely, lowering ethylene biosynthesis reduced the number of somatic embryos in the high capacity cell line. These results were further substantiated by the finding that the effects of amino-oxyacetic acid (AOA), an inhibitor of ethylene biosynthesis, were partially reversed by adding ethylene to both embryogenic cell lines. It is concluded that ethylene is implicated in somatic embryogenesis of black spruce and that the low capacity cell line had excess, i.e. supraoptimal, ethylene production, whereas the high capacity cell line had nearly optimal ethylene production. The relationship between ethylene and other phytohormones, and the possible effects of the interaction between ethylene and polyamines on the maturation of the somatic embryos are discussed.

Amino Acids, Cyclic↗
PubMed1994

Conditioned media produced by follicular shells of different maturity affect maturation of pig oocytes.

The objective of this study was to further test the hypothesis that follicular secretions produced by follicular cells with different maturity affect oocyte cytoplasmic maturation differently. A group of nine gilts were slaughtered on Day 17 of the estrous cycle and another group of ten were slaughtered on Day 20. The five largest and five smallest follicles were selected from the fifteen largest healthy follicles dissected from each pair of ovaries and categorized as large and small follicles, respectively. The five follicular shells in each category were pooled and cultured in 10 ml of modified TCM 199 supplemented with 2.5 micrograms FSH/ml for 48 h with use of a mobile culture system. Afterwards, conditioned media were collected and used for maturing immature porcine oocytes. Each of six replicated experiments consisted of two culture dishes for each conditioned medium: Day 17 small (S17) and Day 17 large (L17), and Day 20 small (S20) and Day 20 large (L20) follicular shells. After 47 h culture, oocytes were inseminated with boar spermatozoa and were fixed 11 h post-insemination to examine fertilization. The average diameters of follicles used were 4.4, 5.7, 6.2, and 7.5 mm for S17, L17, S20, and L20, respectively. Nuclear maturation was slightly higher in oocytes matured in conditioned media produced by large follicular shells than in those produced by small follicular shells (97.0 vs. 93.5%, p = 0.045). Penetrability of oocytes was not affected by treatments.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1997

Amino acids in maturation medium and presence of cumulus cells at fertilization promote male pronuclear formation in porcine oocytes matured and penetrated in vitro.

The present study was conducted to examine the ability of porcine oocytes to achieve male pronuclear (MPN) formation when they are matured and penetrated in vitro under various culture conditions. When cumulus-enclosed oocytes were cultured for 24-48 h in modified Whitten's medium (pH 7.4) supplemented with 10% porcine follicular fluid, 10 IU eCG/ml, and 10 IU hCG/ml (designated mWM-FG), nuclear maturation of oocytes reaching metaphase II was completed by 36 h after the start of culture. However, there were no differences in the proportions (94-95%) of oocytes penetrated in vitro by cryopreserved ejaculated spermatozoa or in the rates (35-45%) of MPN formation between oocytes cultured for 36 and 48 h. When cumulus-enclosed oocytes were cultured for 36 h in mWM-FG supplemented with 2% (v:v) minimal essential medium (MEM) essential amino acids (EAA) with the addition of 0.1 mM glutamine and/or 1% (v:v) MEM nonessential amino acids (NEAA) and inseminated in vitro, 93-97% of oocytes were penetrated regardless of the presence of amino acids during maturation, but the rates of MPN formation were higher in the presence (79-84%) than in the absence (51%) of any amino acids. The addition of EAA+NEAA and/or 0.57 mM cysteine to mWM-FG also did not affect sperm penetration in vitro, while it promoted MPN formation (76-83%) in penetrated oocytes as compared with those matured in the absence of amino acids and cysteine (53%). When oocytes were freed from cumulus cells after culture in mWM-FG, sperm penetration rates were not different between cumulus-enclosed (100%) and cumulus-free (92%) oocytes, but the rate of MPN formation was higher in cumulus-enclosed (53%) than in cumulus-free (28%) oocytes. When EAA+NEAA+cysteine was added to mWM-FG, MPN formation was not improved in cumulus-free oocytes but was much improved (78%) in cumulus-enclosed oocytes. These results indicate that MPN formation in porcine oocytes is promoted by the addition of amino acids and/or cysteine in simple maturation medium and by the presence of cumulus cells at fertilization in vitro.

Amino Acids↗
PubMed1999

Activin stimulation of zebrafish oocyte maturation in vitro and its potential role in mediating gonadotropin-induced oocyte maturation.

Activin plays important roles in the regulation of vertebrate reproduction. Using zebrafish, Danio rerio, as a model, the present study aimed at investigating the role of activin in the regulation of final oocyte maturation. Administration of recombinant goldfish activin B significantly increased the rate of oocyte maturation in vitro in a dose- and time-dependent manner. The effect of activin seemed to be additive to the effects of gonadotropin (hCG) and 17alpha,20beta-dihydroxyprogesterone, a potent maturation-inducing hormone in teleosts. The specificity of the activin action was confirmed by coincubation with recombinant human follistatin, which completely abolished the stimulatory effect of activin B. Interestingly, follistatin also significantly inhibited hCG-induced oocyte maturation, suggesting that endogenous activin may be a downstream mediator of gonadotropin actions. No effect of activin B was observed in the presence of actinomycin D, indicating that the action of activin may involve changes in transcriptional activity. These results, together with the demonstration that activin and its type II receptor are expressed in the zebrafish ovary, strongly suggest a paracrine/autocrine role for activin in the controlling of final oocyte maturation.

Activin Receptors, Type II↗
PubMed2004

Calcium signaling through phospholipase C activates dendritic cells to mature and is necessary for the activation and maturation of dendritic cells induced by diverse agonists.

Calcium is an important second messenger in the phospholipase C (PLC) signal transduction pathway. Calcium signaling is involved in many biological processes, including muscle contraction, cellular activation, and cellular proliferation. Dendritic cell (DC) maturation is induced by many different stimuli, including bacterial lipopolysaccharide (LPS), bacterial toxins, inflammatory cytokines, prostaglandins, as well as calcium mobilization. In the present study, we determined the role of the PLC signal transduction pathway in the activation and maturation of human monocyte-derived DCs (MDDCs) induced by diverse agonists. We found that signaling through PLC activates MDDCs to mature and is necessary for LPS, cholera toxin, dibutyryl-cyclic AMP, prostaglandin E2, and the calcium ionophore A23187 to induce MDDC maturation. The results of the present study along with the results of other studies indicate that multiple signaling pathways are involved in the activation of DCs and that inhibition of any of these pathways inhibits the maturation of DCs.

Bucladesine↗
PubMed1988

Neuroblastoma: incomplete differentiation on the way to maturation or morphological alteration resembling maturity?

The following study was performed to investigate whether antitumor agents can induce maturation of advanced neuroblastoma (NB). Of 56 NB patients (1970-1987), 13 in stage III or IV underwent resection of the primary tumor (11 abdominal, 2 mediastinal) following complete or partial response to preoperative chemotherapy (11 conventional cytotoxic chemotherapy, 2 conventional cytotoxic chemotherapy combined with intraarterial infusion of prostaglandin E1 and oral papaverine). Histological examinations, performed on these 13 NB patients before and after chemotherapy, showed (1) differentiation of the NB to ganglioneuroblastoma (GNB) with predominance of mature atypical ganglion cells, development of stromal components and a few immature malignant cells in 10 of 13 and (2) differentiation of the NB to a more mature form than was seen histologically before treatment in the remaining 3. Our results indicate that the morphological differentiation of immature NB in advanced stage to more mature GNB can be induced by conventional cytotoxic chemotherapy with or without so-called 'maturation-inducing' agents. However, the chemotherapy-induced morphological differentiation did not correlate with the prognosis of the patients.

Alprostadil↗
PubMed1976

Meiotic maturation of mouse oocytes in vitro: inhibition of maturation at specific stages of nuclear progression.

In vitro studies of meiotic maturation of mouse oocytes have been carried out in the presence of several drugs. The individual steps of nuclear progression, including dissolution of the nuclear (germinal vesicle) membrane, condensation of dictyate chromatin into compact bivalents, formation of the first metaphase spindle, and extrusion of the first polar body, are each susceptible to one or more of these drugs. Germinal vesicle breakdown, the initial morphological feature characteristic of meiotic maturation, is inhibited by dibutyryl cyclic AMP. However, even in the presence of dibutyryl cyclic AMP, the nuclear membrane becomes extremely convoluted and condensation of chromatin is initiated but aborts at a stage short of compact bivalents. Germinal vesicle breakdown and chromatin condensation take place in an apparently normal manner in the presence of puromycin, Colcemid, or cytochalasin B. Nuclear progression is blocked at the circular bivalent stage when oocytes are cultured continuously in the presence of puromycin or Colcemid, whereas oocytes cultured in the presence of cytochalasin B proceed to the first meiotic metaphase, form an apparently normal spindle, and arrest. Emission of a polar body is inhibited by all of these drugs. The inhibitory effects of these drugs on meiotic maturation are reversible to varying degrees dependent upon the duration of exposure to the drug and upon the nature of the drug. These studies suggest that dissolution of the mouse oocyte's germinal vesicle and condensation of chromatin are not dependent upon concomitant protein synthesis or upon microtubules. On the other hand, the complete condensation of chromatin into compact bivalents apparently requires breakdown of the germinal vesicle. Failure of homologous chromosomes to separate after normal alignment on the meiotic spindle in the presence of cytochalasin B suggest that microfilaments may be involved in nuclear progression at this stage of maturation. Cytokinesis, in the form of polar body formation, is blocked when any one of the earlier events of maturation fails to take place.

Animals↗
PubMed2004

Faith maturity and doctrinal orthodoxy: a validity study of the faith maturity scale.

This study investigated the factor structure of the 12-item Faith Maturity Scale and the association of Protestant Faith Maturity and Doctrinal Orthodoxy. The sample was taken from 207 urban evangelical church members in southern California. Analysis indicated the Faith Maturity Scale incorporates two factors and Faith Maturity has a weak, positive association with Doctrinal Orthodoxy as tapped by the Christian Doctrinal Orthodoxy Scale. Protestant faith maturity seems to be more independent of doctrinal orthodoxy than generally thought.

Adult↗
PubMed1993

Estimates of maturing rates and masses at maturity for body components of sheep.

Weight data for fleece-free empty body, carcass and offal components, and their chemical constituents (protein, water, lipid, and ash) were collected via serial slaughter techniques. Rams sired by a sheep breed of high genetic merit for growth were slaughtered from birth through 48 mo of age. Approximately six rams were killed at each of 13 slaughter ages. The data were fit with a nonlinear function Yt = A(1-Be-kt) to provide estimates of rates of maturing (k) and weight at maturity (A) for components of interest. Except for the testes, all tissues met the convergence criterion. The proportion of offal components relative to empty BW was greatest at birth and steadily declined after this time. Rates of maturing for visceral organs (except for the heart) and the protein constituent of the offal were of greater magnitude than the carcass and nonprotein constituents of both the offal and carcass. Estimated maturing rate and weight at maturity for lipid of the carcass exceeded corresponding estimates of the offal lipid. Evidence was provided suggesting that the developmental patterns of body components may be established by functional demand.

Animals↗