SEARCH · Search PubMed

Results for “Different developmental stages”

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.

SourceResearch connectionFrom yearThrough year

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

At least 37 records · Page 2Linked to original sources

PubMed1978

[Effectiveness of antigens from various developmental stages of Ascaris suum in the deomonstration of the migratory phase of experimental ascariasis in pigs].

Tests of the efficiency of antigens prepared from different developmental stages of Ascaris suum in indirect haemagglutination test in the course of proving the migration phase of experimental ascariasis in pigs show that the antigens prepared by ultrasound from the invasive larval stage of A. suum in comparison with antigens of sexually mature stages have higher serological activity. By using this antigen it is possible to prove specific antibodies in experimentally invaded pigs from 6 to 120 days after invasion as opposed to the other tested antigens (the detectability of antibodies from the 7th-8th day to the 64th day after invasion).

Animals↗

PubMed1977

Ultrastructure of N-dibutylnitrosamine-induced tumors of the urinary bladder in European hamsters.

European hamsters were treated sc with 0.025 the median lethan dose of N-dibutylnitrosamine. The induced neoplasms of the urinary bladder (transitional cell carcinomas and squamous cell carcinomas) were examined electron microscopically. Their ultrastructure indicated these tumors to be different developmental stages of the same type of tumor rather than two fundamentally different types of neoplasm.

Animals↗

PubMed1978

Histochemical studies on the peroxidase localization in the rat ovary and uterus during various reproductive stages.

A histochemical study has been made of peroxidase changes in rat ovary and uterus during different developmental stages of the normal and pregnant rats. The peroxidase was found to be present in the corpus luteum of the ovary of both normal and pregnant rats as well as in the allantochorionic placenta, while the growing follicles in the immature and mature rat ovary showed no activity. The possible physiological significance of the peroxidase changes in relation to luteal steroidogenesis has been discussed.

Age Factors↗

PubMed1978

Secretory kinetics in the follicular cells of silkmoths during eggshell formation.

Procedures for quantitative autoradiography were used for studying the process of secretion of eggshell (chorion) proteins in the follicular epithelium of silkmoths. The method was based on photometric measurements of the reflectance of vertically illuminated autoradiographic silver grains. Results were analyzed and plotted by computer. Secretory kinetics were also determined by analysis of labeled proteins in physically separated epithelium and chorion. Rapid accumulation of radioactivity into "clumps" visualized by light microscope autoradiography and evidence from preliminary electron microscope autoradiography indicate that, within 2 min from the time of synthesis, labeled chorion proteins move to Golgi regions scattered throughout the cytoplasm. The proteins begin to accumulate in the apical area 10-20 min later and to be discharged from the cell. The time for half-secretion is 20-25 min, and discharge is essentially complete 30-50 min after labeling. At the developmental stages examined, the kinetics of secretion appear to be similar for all proteins. Within the chorion the proteins rapidly assume a characteristic distribution, which varies for different developmental stages. Two relatively slow steps have been identified in secretion, associated with residence in Golgi regions and in the cell apex, respectively. By contrast, translocation of proteins across the cell and deposition of discharged proteins in the chorion are rapid steps.

Animals↗

PubMed2026

Multi-omics analysis reveals stage-associated differences in gut immunity and microbiota between juvenile and adult common carp (Cyprinus carpio).

In vertebrates, the development of intestinal immunity is closely associated with dynamic changes in the gut microbiota. However, stage-associated differences in intestinal immunity and gut microbial communities remain poorly characterized in teleost fish. In this study, transcriptomic analysis combined with 16S rRNA gene sequencing was employed to characterize intestinal immunity and gut microbial communities in juvenile and adult common carp (Cyprinus carpio). Transcriptomic profiling revealed marked developmental differences in intestinal immune function. Juvenile carp exhibited a predominantly innate immune phenotype, characterized by elevated expression of pro-inflammatory cytokines, antimicrobial peptides, and lysozyme-related genes. This immune profile was accompanied by enhanced mucosal barrier function and a relatively pro-inflammatory intestinal environment. In contrast, adult carp displayed increased expression of genes associated with adaptive immunity, suggesting that adult common carp exhibit relatively stronger adaptive immune characteristics than juvenile fish. Gut microbiota analysis demonstrated significant stage-dependent differences in microbial diversity and community composition. Juvenile fish were enriched with bacterial taxa potentially associated with innate immune activation, whereas adult fish harbored distinct microbial communities linked to intestinal homeostasis and barrier maintenance. Furthermore, correlation analyses identified significant associations between specific microbial taxa and innate immune-related gene expression, suggesting a close association between gut microbiota composition and intestinal immune characteristics in juvenile and adult common carp. Collectively, these findings reveal stage-associated differences in intestinal immunity and gut microbial communities between juvenile and adult common carp, thereby providing insights into intestinal immune characteristics at different developmental stages in teleost fish.

Animals↗

PubMed1976

Proteins of chick duodenal brush borders during developmental changes.

Duodenal brush border membrane proteins were studied in chicks at different developmental stages. The protein pattern obtained from polyacrylamide gels with 2-day-old chick preparations was distinctly different from that obtained with 20-day embryos. The most remarkable changes were seen in the region of a protein with an Rf of 0.25, an area with high sucrase and maltase maltase activity, and in the region of a protein with an Rf of 0.28, which was characterized by alkaline phosphatase activity. These proteins reacted strongly with carbohydrate stain after hatching.

Alkaline Phosphatase↗

PubMed1977

Cell wall formation in zoospores of Allomyces arbuscula. III. Carbohydrate composition of cell walls during development from meiospores to hyphae.

Carbohydrate composition was determined in isolated cell walls of meiospores of Allomyces arbuscula after incubation for 15 min (encysted meiospores: cysts), 150 min (germlings: cysts + rhizoids) and 24 h (cysts + rhizoids + hyphae). The principal constituent in all cell wall samples is chitin, accounting for about 75% of the recovered carbohydrates. In addition, cell walls of all stages examined contain polysaccharides which release galactose, glucose, mannose, arabinose, xylose, fucose, and rhamnose on acid hydrolysis. While different developmental stages show minor quantitative changes in chitin, the ratio of galactose to glucose decreases sharply during differentiation of ungerminated cysts into germlings with rhizoids and hyphae. The increase in glucose is accompanied by a decrease in the amount of xylose and/or fucose and of galactose.

Carbohydrates↗

PubMed1979

The development of the hippocampus and dentate gyrus in normal and reeler mice.

The histogenesis, the time of origin and the pattern of migration of the cells in the hippocampus and dentate gyrus, have been studied in normal and reeler mice. The earliest indication of a defect in the reeler hippocampus is seen on the fifteenth embryonic day (E15) which is at least 24 hours after the first indication of a defect in the neocortex. It is not until E18, that the dentate gyrus shows signs of its incipient abnormality. It appears then, that in both the hippocampus and the dentate gyrus the gene defect first manifests itself at the stage at which the definitive cellular layers are assembled. Experiments involving the injection of 3H-thymidine (3H-TdR) at different developmental stages have confirmed that the site and rate of cellular proliferation in the reeler hippocampus and dentate gyrus are normal, as is the initial pattern of cell migration. However, in the reeler dentate gyrus, most postnatal cell proliferation occurs ectopically and in the hippocampus the normal "inside-out" sequence of neurogenesis is reversed, the earliest pyramidal cells generated coming to lie superficially within the stratum pyramidale and the later formed cells being added at progressively deeper levels. There is no discernible gradient in the time of origin of the granule cells in the radial dimension of the reeler dentate gyrus, whereas there is an obvious "outside-in" gradient in the normal animal. The characteristic gradients in cell proliferation seen in the transverse and longitudinal dimensions of the normal dentate gyrus are, however, also evident in the reeler mouse. Taken together, these observations suggest that the reeler gene exerts its effect on neuronal position only in the radial dimension, and does so at a stage of development subsequent to the proliferation and initial migration of the relevant neurons. Timm's sulfide silver preparations indicate that the characteristic staining patterns seen in the dentate gyrus and hippocampus appear at the same time, and mature at the same rate in normal and reeler mice.

Animals↗

PubMed1976

The development patterns of lysosomal enzyme activities during Ca2+-induced sporangium formation in Achyla bisexualis. III. Ribonucleases.

The present paper describes intracellular changes in ribonuclease specific activity during Ca2+-induced sporangium formation in the water mold Achyla bisexualis. The enzymes undergo a decrease in activity prior to crosswall formation followed by an increase in activity during spore cleavage. As spore discharge occurs the RNase activity again decreases. A large percentage of the nuclease activity is associated with a lysosomal-like fraction of the cell, but there is also considerably activity associated with nuclear and microsomal fractions. Addition of cycloheximide or actinomycin D at various times during development prevents further decrease or increase in the enzyme activity. Mixing of cell extracts from different developmental stages provides evidence that inhibitors or activators of the enzyme activity are not responsible for the activity levels evident at the different stages. There is a change in the total levels of presumptive mRNA during Ca2+-induced sporangial formation which appears to be associated with the patterns of RNase activity. Utilizing total cellular RNA and Poly(A)+ RNA with the crude ribonuclease preparations, no substrate specificity could be ascertained.

Calcium↗

PubMedDate not supplied

Glucuronidation and deglucuronidation reactions in hepatic and extrahepatic tissues during perinatal development.

The relative activities of uridine diphosphoglucuronyltransferase (UDPGT) and beta-glucuronidase (betaG) were measured during perinatal development of hepatic and extrahepatic tissues to determine the balance between glucuronidation and deglucuronidation reactions at different developmental stages. Liver, lung, kidney, intestine, and placenta were studied in guinea pigs and rabbits. In general, betaG activities exceeded those of UDPGT in fetal tissues, whereas the converse was evident in adults. There were significant species and age differences in the onset of betaG and UDPGT activities and the occurrence of developmental peaks. A dramatic betaG developmental peak was observed in fetal guinea pig intestine and newborn rabbit intestine. Both microsomal and lysosomal betaG exhibited similar developmental patterns in all tissues tested. Hepatic nonsteroid UDPGT activities were higher at parturition than in adult animals, whereas no such developmental peak occurred for steroid UDPGT. Triton X-100 activated fetal UDPGT in vitro by approximately the same factor as it did for adult UDPGT.

Aging↗

PubMed1976

Nucleic acid and protein differences in Volvox carteri cell types.

Nucleic acids in Volvox carteri have different radioactive labelling patterns in the two cell types, reproductive (gonidia) and somatic. Incorporation of 32P into DNA is maximum during gonidial division in both whole spheroids and isolated somatic and reproductive cells. The most active period of radioactive incorporation into the rRNA of gonidia and somatic cells is during spheroid enlargement, after which the terminally differentiated somatic cells show a steady, continuous decline. Incorporation into the gonidial rRNA declines markedly during late stages of gonidial division but increases during daughter spheroid growth. Polyarylamide gel electrophoresis profiles of cellular proteins are distinctive for spheroids at different developmental stages and also for the isolated cell types.

Cell Division↗

PubMed1978

Physical properties of Artemia salina ribosomes.

Eukaryotic ribosomes were isolated from the cryptobiotic embryos and from the further-developed free-swimming nauplii of the brine shrimp Artemia salina. Analytical boundary sedimentation and photon correlation spectroscopy yielded, respectively, the standard sedimentation and diffusion coefficients at infinite dilution, s degrees 20,w = 81 +/- 1 S and D degrees 20,w = (1.41 +/- 0.02) x 10(-7) cm2/s, for the unfixed and formaldehyde-fixed ribosomes from different developmental stages and for ribosomes attached to a messenger RNA fragment. Also, the density increment was determined, from which the partial specific volume was derived (0.63 +/- 0.01 cm3/g). Combination of the different measured parameters gives accurate values for the molecular weight (3.8 +/- 0.1) x 106 and for size and solvation parameters. These results are compared with their counterparts for the smaller ribosomes from the prokaryote Escherichia coli.

Animals↗

PubMed1976

Matrix vesicle heterogeneity: possible morphogenetic functions for matrix vesicles.

Extracellular membranous matrix vesicles were localized and described using electronmicroscopy during chondrogenesis, osteogenesis, and dentinogenesis. Evidence indicates that matrix vesicles in each of these specific tissue types function to concentrate and transport ions and enzymes which serve as nucleation sites for the mineralization of hydroxylapatite. We have examined different developmental stages of Meckel's cartilage, alveolar bone and epithelial-mesenchymal interactions associated with tooth formation in newborn mice. These ultrastructural studies indicate matrix vesicle heterogeneity. Whereas most matrix vesicles contain alkaline phosphatase activity during cartilage, bone and dentine mineralization, in earlier developmental stages matrix vesicles contain acid phosphatase activities and little, if any, alkaline phosphatase. Tissue type, specific developmental stage, and ultrastructural criteria indicate various "classes" of matrix vesicles. During epithelial-mesenchymal interactions in tooth development, mesenchymal cells (preodontoblasts) appear to be the source of matrix vesicles as indicated by the complementarity between H-2 histocompatibility alloantigen specificity on the cell surface and that of the matrix vesicle outer surface; matrix vesicles are limited by a trilaminar membrane derived from the mesenchymal cells. Some of the vesicles located adjacent to dividing inner enamel epithelial cells contain RNA's as determined by electron microscopic autoradiography in situ, as well as by direct biochemical assays. We postulate that matrix vesicles have many different and important biological functions, one of which may be to mediate developmental information from mesenchyme to epithelia during "instructive" stages of tooth development.

Animals↗

PubMed1978

Some observations on the development of the human hyoid bone.

Investigations on the human hyoid bone in several developmental stages reveal that with the chondrification of the mesenchymal blastema a typical interzone between the body and the greater cornua is formed. This disc of closely packed blastemal cells, distinct and broad in the earlier stages, is reduced in thickness in the course of further development. In fetuses between 5 and 6 months old and in newborns the formation of joint cavities can be seen in some cases. In other cases, however, a small transverse line of cells persists between the two cartilaginous elements. These findings are interpreted as different developmental stages of a diarthrosis generally formed between the corpus and the cornu majus. The fact that in the adult the lesser horn is connected directly to the cornu majus and not to the body is confirmed by the embryological investigations reported in this study.

Humans↗

PubMed1978

Distribution and accumulation of alkaloids in Catharanthus roseus G. Don during development.

Pattern of the total alkaloids distribution and accumulation in Catharanthus roseus G. Don was investigated during six different stages of flowering and fruiting. The highest concentration of alkaloids (mg perivine/g dry weight) was found in the roots at the start of flowering and the minimum in the stems during full fruiting stage; the rate of alkaloidal accumulation in the leaves, stems and roots tended to decrease during fruit maturation. The most active stage of alkaloidal biosynthesis was at the start of flowering in all vegetative organs. The maximum dry weights of leaves, stems and roots were obtained during the start of fruiting. The weights of flowers and fruits were relatively very small during different developmental stages. Harvesting Catharanthus roseus should best be carried out at the full-flowering stage to obtain the optimum yield of total alkaloidal content of leaves, stems and roots (as mg perivine/total dry weight of each organ per plant).

Plants, Medicinal↗

PubMed1979

Physiological characterization of a biphasic immune response to Trichinella spiralis in the rat.

Secondary infection with Trichinella spiralis in the rat was associated with a host response that prevented approximately 80% of the total number of larvae recovered after primary infection from embedding in the intestine. The host response occurred within 15 min after contract of the parasite with intestinal mucosa and was not associated with acute inflammatory cell infiltrates or with the pathophysiology of the primary infection. Eventual rejection of the residual population of embedded worms occurred between four and eight days after infection and involved tissue changes similar to those attending worm rejection during primary infection. Elimination of enteric stages of T. spiralis in primary infection probably involves a single response aimed at the expulsion of established worms. In contrast, immune rejection of worms in secondary infection involves physiologically and presumably immunologically distinct "early" and "late" responses, with each response having a different developmental stage of the parasite as its target.

Animals↗

PubMed1977

Extracellular matrix synthesis in blastula and gastrula stages of normal and hybrid frog embryos. II. Autoradiographic observations on the sites of synthesis and mode of transport of galactose- and glucosamine-labelled materials.

Pulse-chase labelling experiments and light- and electron-microscopic autoradiography were used to examine the sites of synthesis, mode of transport, and sites of deposition of galactose- and glucosamine-labelled materials in different developmental stages of normal developing Rana pipiens embryos and interspecific hybrid embryos formed by fertilizing the eggs of R. pipiens with the sperm of R. catesbeiana. In both normal and hybrid embryos, after 15-min pulse, grains are closely associated with juxtanuclear and cytoplasmic collections of membrane-bound vesicles which resemble the Golgi apparatus. In normal embryos following a 15-30 min pulse and a 60-min chase, grains are largely cleared from the cytoplasmic vesicles and deposited in the extracellular spaces or along cell surfaces where the extracellular spaces are relatively large. In contrast, arrested hybrid embryos given a 15-30-min pulse and a 60-min chase show a marked accumulation of grains over cytoplasmic structures such as the Golgi apparatus and vesicular elements in the cell cortex. Finally, early gastrula stage normal embryos are most active in the synthesis of galactose-labelled materials in cells above the dorsal lip of the blastopore, where cell migration is initiated.

Animals↗

PubMed1977

[The role of cytochrome P450 in the activation of drugs (author's transl)].

Unspecific microsomal monooxygenases have been found in many organisms of different developmental stages. In higher organisms liver is the main organ of drug metabolism but smaller intestine, lung and skin also show this activity. The corresponding membrane-bound enzyme system could be isolated by modern chromatographic techniques and was found to consist of a reductase and a series of cytochrome P450 enzymes. Each of these cytochromes has a different, but with other forms overlapping substrate specificity. The steady-state concentrations of the various forms is regulated by induction with drugs and foreign compounds. The unspecificity of the systems is also reflected in the varying pattern of metabolites. In general stable and more polar metabolites are formed by the monooxygenation reaction, but reactive and unstable products may also appear, e.g. N-hydroxy compounds, 1,2-diphenols, epoxides and a new class of compounds which have been characterized as carbenes.

Adult↗