ABSTRACT
Objetivo: demonstrar, por meio de uma revisão de literatura, a utilização do hormônio do crescimento (GH) e concentrados plaquetários e sugerir técnica de associação de uso para odontologia em processos de preservação de osso alveolar. Revisão de literatura: enxertos ósseos são uma necessidade na área da saúde, por diversas razões. A utilização de osso autógeno apresenta grande desvantagem em ter um segundo sítio cirúrgico, entretanto, os substitutos ósseos não possuem as características ideais. Assim, existe a busca por alternativas que otimizem a cicatrização e a incorporação dos substitutos ósseos, dentre elas os concentrados sanguíneos, ricos em fatores de crescimento derivados das plaquetas e o hormônio do crescimento. É possível encontrar uma vasta literatura utilizando os concentrados sanguíneos, inclusive utilizando esses como veículos para outras substâncias. Os concentrados sanguíneos são ricos em fatores de crescimento derivados das plaquetas, como fator de crescimento semelhante à insulina (IGF), Fator de crescimento derivado de plaquetas (PDGF) e outros. Além disso, também é possível encontrar, na literatura, o uso tópico de hormônio do crescimento em enxertos ósseos, fraturas e implantes dentários. Entretanto, o GH possui uma meia-vida de 20 minutos, assim, quando utilizado em conjunto com a I-PRF, espera-se um aumento no tempo de ação local. Considerações finais: é possível otimizar os enxertos ósseos utilizando-se L-PRF/I-PRF e hormônio do crescimento. Porém, são necessárias mais pesquisas.(AU)
Objective: this study aims to show through a literature review the use of the growth hormone and platelet concentrates and to suggest an association technique for dentistry use in alveolar bone preservation processes. Literature review: bone grafts are a health requirement for a number of reasons. The use of autogenous bone has the main disadvantage of a second surgical site, while bone substitutes do not present optimal characteristics. Thus, there is a search for alternatives that optimize the healing and incorporation of bone substitutes, which include blood concentrates that are rich in platelet-derived growth factors and the growth hormone. A vast literature can be found on blood concentrates, including their use as vehicles to other substances. Blood concentrates are rich in platelet-derived growth factors such as IGF, PDGF, and others. Moreover, the literature also shows the topical use of the growth hormone in bone grafts, fractures, and dental implants. However, the growth hormone presents a half-life of 20 minutes; therefore, when combined with I-PRF, an increased time in local action is expected. Final considerations: it is possible to optimize bone grafts by using L-PRF/I-PRF and the growth hormone. However, further research is required.(AU)
Subject(s)
Humans , Growth Hormone/therapeutic use , Alveolar Process/physiopathology , Alveolar Ridge Augmentation/methods , Platelet-Rich Fibrin , Combined Modality TherapyABSTRACT
Growth hormone [GH] is licensed for use in children born small for gestational age (SGA) who fail to catch-up. We retrospectively compared the response of twenty children born SGA (who satisfied the auxological criteria) to growth hormone (Group I) versus randomly selected age and sex matched controls from a group of SGA children with growth related complaints, not treated with GH (Group II). After 2 years of GH therapy the HAZ increased from -2.8 to -1.6 in Group I, compared 2.2 to -1.7 in group II (P-value < 0.05). The percentage of pubertal children rose from 55% to 65% in cases versus 60% to 75% in the controls (P>0.05). GH resulted in increase in growth velocity Z-score during the first year and (4.3±0.5 in Group-I versus - 0.5±0.6 in Group-II, P<0.05) second year of treatment (1.7±0.4 in cases versus -0.6±0.7 in controls, P<0.05).Thus, GH improves height of short SGA children without accelerating pubertal progression.
ABSTRACT
Two active mutations (A 781 G and A 1575 G) in growth hormone (GH) gene, and their associations with litter size (LS), were investigated in both a high prolificacy (Matou, n = 182) and a low prolificacy breed (Boer, n = 352) by using the PCR-RFLP method. Superovulation experiments were designed in 57 dams, in order to evaluate the effect of different genotypes of the GH gene on superovulation response. Two genotypes (AA and AB, CC and CD) in each mutation were detected in these two goat breeds. Neither BB nor DD homozygous genotypes were observed. The genotypic frequencies of AB and CC were significantly higher than those of AA and CD. In the third parity, Matou dams with AB or CC genotypes had significantly larger litter sizes than those with AA and CD (p < 0.05). On combining the two loci, both Matou and Boer dams with ABCD genotype had the largest litter sizes when compared to the other genotypes (p < 0.05). When undergoing like superovulation treatments, a significantly higher number of corpora lutea and ova, with a lower incidence of ovarian cysts, were harvested in the AB and CC genotypes than in AA and CD. These results show that the two loci of GH gene are highly associated with abundant prolificacy and superovulation response in goat breeds.
ABSTRACT
Um número crescente de pesquisas envolvendo a suplementação de aminoácidos isolados sobre o desempenho físico vem sendo realizado, mas os efeitos e os possíveis mecanismos de ação de muitos deles ainda permanecem inconclusivos. Destes, um aminoácido que vem sendo amplamente estudado, e que já faz parte da composição de inúmeros suplementos nutricionais, é a L-arginina pelo seu possível papel na estimulação da secreção do hormônio do crescimento (GH) e da insulina, além de ser um indutor da vasodilatação dependente de óxido nítrico (NO). Diversos estudos indicam que a suplementação de L-arginina pode estimular signifi cativa secreção do GH no repouso e, quando associada ao exercício, pode promover um feedback hipotalâmico negativo com conseqüente diminuição da secreção deste hormônio. A síntese protéica muscular tem sido associado à vasodilatação promovida pela L-arginina o que, em parte, pode ser considerado errôneo pelo fato desta isoladamente não aumentar a disponibilidade de substratos para recuperação muscular. Contudo, estudos que envolvem L-arginina e desempenho esportivo, bem como aqueles investigam dose e tempo de consumo desse aminoácido, são confl itantes e refl etem a escassez de trabalhos nesse contexto. A presente revisão descreve os aspectos metabólicos e possíveis efeitos ergogênicos da suplementação de L-arginina sobre o exercício físico.
A growing number of studies involving isolated aminoacids supplementation on physical performance have been achieved, but the effects and possible mechanisms of action of many of them still remain unclear. Of these, an amino acid that has been widely studied, and that is already part of the composition of many nutritional supplements, is L-arginine for its possible role in stimulating growth hormone (GH) and insulin release, beyond to be a nitric oxide dependent vasodilation inducer (NO). Several studies indicate that L-arginine supplementation can signifi cantly stimulate basal GH release and, when associated with exercise, can promote a negative hypothalamic feedback with consequent attenuation of release. Skeletal muscle protein synthesis has been associated with L-arginine-induced vasodilation which, in part, can be considered erroneous because alone it does not increase substrates availability for muscle recovery. However, studies involving L-arginine and exercise performance, as well as those investigating dose and time of consumption of this aminoacid are confl icting and refl ect the shortage of works in this context. This review describes the metabolic aspects and possible ergogenic effects of L-arginine supplementation on exercise.
Subject(s)
Humans , Amino Acids , Arginine , Athletic Performance , Growth Hormone , Insulin , Nitric Oxide , Performance-Enhancing SubstancesABSTRACT
PURPOSE: Gonadotropin releasing hormone analogue (GnRHa) or growth hormone (GH) improve final height in girls with central precocious puberty. We studied the effect of these agents on adult height in children with advanced puberty. METHODS: We analysed height, bone age, growth velocity, predicted adult height (PAH), and final adult height (FAH) in 61 girls and 19 boys with advanced puberty, who were treated with GnRHa combined GH or GH. RESULTS: In Girls 1) FAH (SDS) of combination group (GnRHa+GH, n=7) was similar to their pretreatment PAH (SDS) [153.9+/-6.0 cm (-1.3+/-1.2) vs 152.8+/-4.7 cm (-1.5+/-0.9)]. In GH group (n=18), FAH was significantly increased [155.7+/-4.9 cm (-0.9+/-1.0) vs 149.9+/-4.6 cm (-2.1+/-0.9)] (P<0.001). 2) PAH (SDS) of combination group increased from 151.5+/-5.9 cm (-1.8+/-1.2) to 157.8+/-7.1 cm (-0.5+/-1.4) and that of GH group increased from 149.5+/-5.9 cm (-2.2+/-1.2) to 155.8+/-5.8 cm (-0.9+/-1.2) (P<0.001). During first year of treatment, growth velocity of GH group was significantly higher than that of combination group (6.6+/-2.1 cm/year vs 9.4+/-2.5 cm/year, P=0.001) In boys 1) In both group (7 boys of combination group and 8 boys of GH group), FAH was similar to their pretreatment PAH and their growth velocity during first year of treatment had no significant difference (7.6+/-2.3 cm/year vs 9.2+/-2.9 cm/year). CONCLUSION: In girls with advanced puberty, GnRHa delayed bone maturation but had no significant effect on FAH. In contrast, GH increased FAH through increment of growth velociy. In boys with advanced puberty, no significant effect of GnRHa or GH.
Subject(s)
Adolescent , Adult , Child , Female , Humans , Gonadotropin-Releasing Hormone , Gonadotropins , Growth Hormone , Puberty , Puberty, PrecociousABSTRACT
Objective To study the preparation and the in vitro and in vivo release profile of GH-Chitosan-Alginate microcapsules.Methods GH-Chitosan-Alginate microcapsules were prepared through impulsive electrostatic technique.The interrelated factors influencing the diameter and sphericity were studied through orthogonal experiments,and finally the statistic analysis made sure the optimum conditions to prepare microspheres.The morphology and size of the microcapsules were observed,and the content,encapsulation efficiency and recovery efficiency of the microcapsules were measured.Moreover,their in vitro and in vivo release experiments were carried out.Results The results showed that the diameter of needle was the most significant factor to the diameter of microspheres.The optimum conditions for the least diameter of microspheres were 450?m diameter of needle,2cm from needle tips to the gelation surfaee,1.5% alginate concentration,8ml/h speed of flowing-liquid and metal containers.The microcapsules had good sphericity morphology and distribution.The size of the microcapsules was in the range of 10-25?m with an average size of 47.93?m.The encapsulation efficiency and GH-load of the microcapsules were 94% and 11.24% respectively.The release kinetics of microcapsules was studied in false gastric and intestines juice.In false gastric juice,the GH of microcapsules was not released;in false intestines juice,it was released well,and TAM was completely released after about 12h.in vivo release profile made sure that the serum GH level of GH microcapsule group was at the highest value(98.59ng/ml) at 8h.The release profile was fitted well in both in vitro and in vivo conditions.Conclusion GH-Chitosan-Alginate Microcapsules have good morphology and sustained release effect.
ABSTRACT
Objective To investigate the relationship between intrauterine growth retardation (IUGR) and en docrine parameters so as to assess the effects of the main endocrine factors on IUGR. The concentrations of growth hormone (GH), insulin, T3, T4 and TSH were measured in umbilical cord blood, amniotic fluid and maternal serum. Methods The samples were collected from 23 pregnant women who were diagnosed as the full term IUGR, 42 normal full term pregnant women with normal infants' weight were taken as control. Growth hormone and insulin were mea sured by radioimmunoassay. T3, T4 and TSH were investigated by micro-radioimmunoassay. Results The concentra tions of growth hormone, insulin and T4 in umbilical cord blood were lower in IUGR than that in control group(GH 4. 63μg/L vs 7.01μg/L, insulin 10. 68μIU/ml vs 31.44μIU/ml, T4 87. 39nmol/L vs 138. 10nmol/L. P ＜0. 05, 0. 05 and 0. 05, respectively). The TSH concentration in umbilical cord blood was higher in IUGR than in control group (10. 84μmIU/L vs 5. 75μmIU/L, P ＜0. 01). The concentration of growth hormone in maternal serum and the concen tration of insulin in amniotic fluid were also lower in IUGR group than in control group(GH 1.77μg/L vs 2.74μg/L, P ＜0. 01, insulin 5. 84μIU/mi vs 15. 64μIU/ml, P ＜0. 01). Conclusion This study confirms that full term neonates with IUGR are abnormal in endocrine factors. The inadequacy of growth hormone may be one of the causes of IUGR. The relative scarcity of growth hormone and insulin seems to be a factor to compromise the fetus' metabolism. Be sides, the early hypothyrosis of infants with IUGR might protect them from unfavorable environment in the uterine.
ABSTRACT
The effects of growth hormone(GH) deficiency and recombinant human GH replacement(0.5IU/kg per week) on bone mineral metabolism in 21GH-deficiency children were studied. All children had significantly reduction of bone density(Z score;-1.4+-0.71). After 1 month of therapy, the levels of serum insulin-like growth factor 1(IGF-1), osteocalcin(OC) and carboxyterminal propeptede of type 1 procollagen(PICP) were significantly elevated. But IGFBP-3 were not shown to change significantly. The changes in serum levels of PICP during the first month of recombinant human GH treatment were positively related to growth velocity, whereas the changes in IGF-1 and OC during the first month of therapy were not. We conclude that the recombinant human GH treatment caused significant modifications of mineral metablism and that the measurement of the changes of biochemical markers of bone metablism espacially PICP may be a useful tool in prediction improved growth velocity during long term GH replacement therpy.