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Serum levels of type I procollagen C-terminal propeptide, insulin-like growth factor-I (IGF-I), and IGF binding protein-3 in obese children and adolescents: relationship to gender, pubertal development, growth, insulin, and nutritional status.

We measured fasting serum levels of type I procollagen C-terminal propeptide (PICP), insulin-like growth factor-I (IGF-I), and IGF binding protein-3 (IGFBP-3) in obese children and adolescents (obese subjects [OS]) to evaluate their relationship to growth, gender, pubertal stage, and weight excess (WE). The influence of insulin, growth hormone (GH), and weight loss was also studied. The study population consisted of 244 OS and 236 normal-weight subjects (NWS) matched for age, gender, and pubertal stage. At stage I, OS had a higher standard deviation score (SDS) for height than NWS of both genders. During the prepubertal phase, growth velocity (GV) was greater in OS than in NWS of both genders, but it was lower in female OS at stage II and male OS at stage III. PICP increased in puberty, with a more rapid decrease later in female OS and NWS; prepubertal values were higher in OS but were reduced at pubertal stage IV to V in comparison to NWS. Stepwise multiple regression analysis demonstrated that GV was the only anthropological variable correlating with PICP. IGF-I serum values increased significantly in puberty and were higher in OS than in NWS at stage I for both genders. IGFBP-3 values of OS exceeded those of NWS at stages I to III in males and I to II in females. No difference was observed for males versus females in each group, nor was any difference observed for the IGF-I/IGFBP-3 molar ratio between the two groups. Using stepwise analysis, a positive correlation between IGF-1 and IGFBP-3 was observed in prepubertal but not in pubertal NWS. Fasting insulin values correlated with IGFBP-3 in OS, accounting for 24.8% of the variation in prepubertal subjects and 17.1% in pubertal subjects. No such correlation was observed in NWS. In prepubertal NWS, PICP and SDS of body mass index (BMI) correlated with IGF-I, accounting for 12.9% of the variation, and SDS of BMI correlated with IGFBP-3, explaining 27.8% of the variation. In prepubertal OS, no such correlations could be observed, but PICP and SDS of BMI accounted for 14.3% of the variation in the IGF-I/IGFBP-3 molar ratio. A significant reduction of IGFBP-3 and an increase of the IGF-I/IGFBP-3 molar ratio were detected after weight loss in 40 OS. In conclusion, we demonstrated that IGF-I and IGFBP-3 are influenced by age, gender, sexual development, and nutritional status. Also, an influence of insulin on IGFBP-3 serum levels was observed in OS. The relations of IGF-I to PICP in NWS and of the IGF-I/IGFBP-3 molar ratio to PICP in OS support the concept of IGF-I influence on skeletal growth. The increased IGFBP-3 serum values in OS suggest a possible role in controlling the growth stimulus induced by nutritional status.

Adolescent↗

Growth, development, and gene expression by in vivo- and in vitro-produced day 7 and 16 bovine embryos.

The effects of the embryo production system on growth and transcription rate of day 7 and 16 bovine embryos were investigated. In vivo- (controls) and in vitro-produced (IVP) embryos were transferred to female recipients on day 7 of development, and were allowed to develop in a synchronous uterine environment to day 16. Embryonic transcripts for insulin-like growth factors-1 and -2 (IGF-1 and -2), their receptors (IGF-1r and -2r), facilitative glucose transporters-1 and -3 (Glut-1 and -3), and interferon-tau (IFN-tau) were determined by real-time quantitative PCR (TaqMan); gender diagnosis was performed on day 16 concepti only. On day 7, IVP embryos presented lower mRNA levels than controls (P < 0.05), but these differences were generally reduced on day 16. No IGF-1 transcripts were detected on day 7, but a low IGF-1 mRNA level was observed in day 16 embryos. In the IVP group, IFN-tau mRNA levels were lower on day 7 (P < 0.05), but higher than controls on day 16 (P < 0.05). Control embryos showed a temporal decrease in the relative transcription from day 7 to 16 (P < 0.05), except IGF-1 mRNA. On day 16, IVP concepti were shorter and displayed smaller embryonic discs (P < 0.05). Female concepti were generally smaller than males, and IGF-2r mRNA and growth were negatively correlated. The in vitro production of bovine embryos negatively affected the amount of gene expression on day 7 and the rate of development on day 16. Physical traits and transcriptional activity on day 16 were associated with one another, which appeared to be significant for growth and development.

Animals↗

Adipose tissue development, growth, and food consumption in protein-malnourished rats.

Effects of protein malnutrition on adipose tissue development were studied in weanling male Sprague-Dawley rats fed isocaloric diets ad libitum containing either 22% (controls) or 8% (protein-malnourished rats) casein, and in rats pair-fed to the protein-malnourished rats with the 22% casein diet. After 32 days on the diet, protein-malnourished rats were 37% and pair-fed 67% the weight of the controls, while torso length was 37% and 73% of controls, respectively. Food consumption relative to body weight was greatest in protein-malnourished rats. Compared to control rats, the distal epididymal adipocyte number in the protein-malnourished rats was decreased in proportion to the decrease in body size and was more closely related to the protein intake than to the total calories consumed. After 32 days on diet, mean adipocyte number per 2 distal pads was 11.7 x 10(6) in controls and 4.3 x 10(6) in protein-malnourished rats. In pair-fed rats, cell number lagged behind controls at 4 and 11 days, but was normal at 32 days (11.4 x 10(6) cells). The distal epididymal pad adipocyte size and percent lipid were similar in all groups during the first 25 days of dietary treatment. Adipocyte size was increased significantly in controls at day 32 compared to the other two groups. At each time studied through day 25 on diet, epididymal pad weight was related to the adipose cell number rather than the cell size. It is concluded that severe restriction of dietary protein during the postweaning period of growth in rats results in decreased epididymal adipocyte proliferation and/or differentiation concomitant with generalized growth retardation, whereas isocaloric feeding of a diet of normal protein content is associated with only a transient delay in adipose tissue development.

Adipose Tissue↗

Photoreceptor differentiation during retinal development, growth, and regeneration in a metamorphic vertebrate.

To test the hypothesis that growth and regeneration of the adult retina involves a mechanistic recapitulation of retinal development, the patterns of photoreceptor differentiation were investigated in the developing retina, as well as growing and regenerating adult retina, of a metamorphic vertebrate, the winter flounder. Only one opsin, of type RH2 (a "green" cone opsin), was expressed in premetamorphic (developing) retina, and a corresponding middle-wavelength visual pigment was observed. In premetamorphic retinas there was no evidence for any other cone opsins or pigments, rods, rod opsin expression, or rod visual pigment. In contrast, a rod opsin (RH1) and three cone opsins (SWS2, RH2, and LWS) were expressed in postmetamorphic (adult) retina, and these opsins were consistent with the observed repertoire of visual pigments. During postmetamorphic retinal growth and regeneration, cones were always produced before rods, but the different cone types were apparently produced simultaneously, suggesting that cone differentiation mechanisms might change after metamorphosis. The results support the hypothesis that photoreceptor differentiation during growth and regeneration of the adult retina involves a recapitulation of mechanisms that control the sequence of photoreceptor production during retinal development.

Amino Acid Sequence↗

[Puberty and growth development in patients with a 21-hydroxylase defect].

Twenty six females suffering from congenital adrenal hyperplasia due to 21-hydroxylase-deficiency with and without salt wasting were evaluated to determine their growth patterns with special regard to their pubertal growth spurt. 17 patients have been substituted with hydrocortisone 20-25 mg/m2 and if necessary with 9 alpha-fluoro-cortisol 0.025-0.15 mg (group 1), 9 patients have got an additional cyproterone-acetate-therapy during their pubertal development (group 2). Group 1: A pubertal growth spurt was found in 14 females (82.4%) with a peak height velocity of 6.2 +/- 1.6 (SD) cm/yr. At the beginning of puberty the early treated girls showed a progressing retardation of bone age. Therefore the peak height velocity based on advancing bone age was elevated up to 8.7 +/- 1.4 (SD) cm/yr bone age (p = 0.01). Salt wasting (n = 10) did not seem to influence the pubertal growth velocity and the pubertal growth spurt (p = 0.1, p greater than 0.1), but the growth until cessation which was found to be markedly decreased (p less than 0.1). Group 2: Cyproterone-acetate suppressed symptoms of puberty but did not extinguish growth spurt. During 6.3 +/- 1.3 (SD) yrs of treatment bone age advanced only 4.2 +/- 0.7 (SD) yrs. However, in this period height increased by 20.8 +/- 6.4 (SD) cm which corresponds to a mean height velocity of 3.3 +/- 0.8 (SD) cm/yr, and 4.9 +/- 0.8 (SD) cm/yr bone age. Furthermore at puberty peak height velocity results in 4.5 +/- 0.7 (SD) cm/yr and in 10.4 +/- 4.6 (SD) cm/yr bone age.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Studies on growth, development, and infectivity of Philophthalmus hegeneri Penner and Fried 1963 in the chick.

A reinvestigation of the growth curve of Philophthalmus hegeneri in chicks showed rapid growth for the first 17 days after infection. After this, the growth rate declined for multiple infections (two or more worms per eye), and after 20 days, adults in monometacercarial infections ceased appreciable growth and never attained reproductive maturity. These results are similar to those reported by Fried (1962), but here adults were approximately 0.5 mm shorter in all cases and were slower in producing mature eggs. When worms from 28 to 36 days old from monometacercarial infections were transplanted into multiple infections, normal growth occurred. Worms recovered from multiple infections and transplanted singly grew normally for at least 18 days but recovery rates were extremely low. When P. hegeneri adults over 20 days old from monometacercarial infections were transplanted singly with Philophthalmus megalurus adults, growth was not stimulated in either species.

Animals↗

The nuclear hormone receptor coactivator NRC is a pleiotropic modulator affecting growth, development, apoptosis, reproduction, and wound repair.

Nuclear hormone receptor coregulator (NRC) is a 2,063-amino-acid coregulator of nuclear hormone receptors and other transcription factors (e.g., c-Fos, c-Jun, and NF-kappaB). We and others have generated C57BL/6-129S6 hybrid (C57/129) NRC(+/-) mice that appear outwardly normal and grow and reproduce. In contrast, homozygous deletion of the NRC gene is embryonic lethal. NRC(-/-) embryos are always smaller than NRC(+/+) embryos, and NRC(-/-) embryos die between 8.5 and 12.5 days postcoitus (dpc), suggesting that NRC has a pleotrophic effect on growth. To study this, we derived mouse embryonic fibroblasts (MEFs) from 12.5-dpc embryos, which revealed that NRC(-/-) MEFs exhibit a high rate of apoptosis. Furthermore, a small interfering RNA that targets mouse NRC leads to enhanced apoptosis of wild-type MEFs. The finding that C57/129 NRC(+/-) mice exhibit no apparent phenotype prompted us to develop 129S6 NRC(+/-) mice, since the phenotype(s) of certain gene deletions may be strain dependent. In contrast with C57/129 NRC(+/-) females, 20% of 129S6 NRC(+/-) females are infertile while 80% are hypofertile. The 129S6 NRC(+/-) males produce offspring when crossed with wild-type 129S6 females, although fertility is reduced. The 129S6 NRC(+/-) mice tend to be stunted in their growth compared with their wild-type littermates and exhibit increased postnatal mortality. Lastly, both C57/129 NRC(+/-) and 129S6 NRC(+/-) mice exhibit a spontaneous wound healing defect, indicating that NRC plays an important role in that process. Our findings reveal that NRC is a coregulator that controls many cellular and physiologic processes ranging from growth and development to reproduction and wound repair.

Animals↗

Role of neuroendocrine hormones in murine T cell development. Growth hormone exerts thymopoietic effects in vivo.

Growth hormone (GH) and other neuroendocrine mediators have been implicated previously in T cell development. We therefore examined thymic development in DW/J dwarf mice. DW/J mice lack acidophilic anterior pituitary cells and consequently are totally deficient in the production of GH, as well as other neuroendocrine hormones. DW/J dwarf mice had greatly hypoplastic thymi that continued to decrease in size as the mice aged. Characterization of the different T cell subpopulations within the thymi of dwarf mice indicated a deficiency in CD4+/CD8+ double-positive thymocytes. This deficiency of progenitor cells became more complete as the mice aged culminating in the total disappearance of this subpopulation in some dwarf mice > 3 mo of age. Analysis of the lymph nodes indicated that a population of double-positive (CD4/CD8) T cells appeared in some mice concurrent with the disappearance of double-positive cells in the thymus suggesting that these thymocytes may have migrated to the periphery. However, peripheral T cells from dwarf mice did exhibit Ag-specific responses indicating that these mice have functional T cells. Treatment of the mice with recombinant human GH, which binds both murine growth hormone receptors and murine prolactin receptors, or ovine GH, which binds murine growth hormone receptors but not murine prolactin receptors, resulted in an increase in thymic size and the reappearance of the CD4+/CD8+ double-positive cells within the thymus. Additionally, after GH treatment, the double-positive cells disappeared from the lymph nodes. The thymi of mice treated with GH failed to attain normal size but did develop a normal distribution of T cell progenitors. Thus, GH exerts significant thymopoietic effects in vivo. Neuroendocrine hormones may be important for normal T cell differentiation to occur within the murine thymus.

Animals↗

[Biology and physiology of development, growth and reproduction of electric rays. Survey of research since 1965].

Since 1965, various works have pointed to electric rays (chiefly Torpedo marmorata and T. torpedo = T. ocellata) as an interesting material for the biological and physiological research on development (especially that of electric organs), growth and reproduction. In a review of the main published results, attention is called upon several points requiring new studies (buoyancy and its regulation during gestation time, neuroendocrine control of gestation, etc.). T. torpedo, a much abundant species in the Bay of Tunis, seems by far the most well-suited material for this, because of its annual reproductive cycle. New results concerning T. m. are also presented: gestation length, embryo retention, and weight changes of the yolk sacs. The microscopic structure of the female genital tract is illustrated.

Aging↗

Development, growth rate, degree of malignancy, and chromosome pattern of Morris transplantable hepatomas.

A spectrum of chemically induced transplantable adenocarcinomas of the rat hepatocyte was developed in inbred strains of rats. For the most part, the tumors showed remarkable stability in growth rate between 1973 and 1976, as determined by months between transfers. A few tumors were slower-growing in 1976 than in 1973, and a few tumors of intermediate growth rate were somewhat slower-growing in 1973 than in 1976. Percentage distributions of chromosomes of six aneuploid hepatoma are presented. The most homogeneous cell lines were a haploid and a hyperdiploid line. The karyotype of each hepatoma had a consistent number of abnormal chromosomes. Lung metastases were observed in almost all cell lines.

Animals↗