Growth hormone therapy

Gamma-Aminobutyric Acid (GABA) Promotes Growth in Zebrafish Larvae by Inducing IGF-1 Expression via GABAA and GABAB Receptors

Insulin-like growth factor-1 (IGF-1) primarily increases the release of gamma-aminobutyric acid (GABA) in neurons; moreover, it is responsible for the promotion of longitudinal growth in children and adolescents. Therefore, in this study, we investigated whether exogenous GABA supplementation activates IGF-mediated growth performance. Zebrafish larvae treated with GABA at three days post fertilization (dpf) showed a significant increase in the total body length from 6 to 12 dpf through upregulation of growth-stimulating genes, including IGF-1, growth hormone-1 (GH-1), growth hormone receptor-1 (GHR-1), and cholecystokinin A (CCKA). In particular, at 9 dpf, GABA increased total body length from 3.60 ± 0.02 to 3.79 ± 0.03, 3.89 ± 0.02, and 3.92 ± 0.04 mm at concentrations of 6.25, 12.5, and 25 mM, and the effect of GABA at 25 mM was comparable to 4 mM β-glycerophosphate (GP)-treated larvae (3.98 ± 0.02 mm). Additionally, the highest concentration of GABA (50 mM) -induced death in 50% zebrafish larvae at 12 dpf. GABA also enhanced IGF-1 expression and secretion in preosteoblast MC3T3-E1 cells, concomitant with high levels of the IGF-1 receptor gene (IGF-1R). In zebrafish larvae, the GABA-induced growth rate was remarkably decreased in the presence of an IGF-1R inhibitor, picropodophyllin (PPP), which indicates that GABA-induced IGF-1 enhances growth rate via IGF-1R. Furthermore, we investigated the effect of GABA receptors on growth performance along with IGF-1 activation. Inhibitors of GABA_A and GABA_B receptors, namely bicuculline and CGP 46381, respectively, considerably inhibited GABA-induced growth rate in zebrafish larvae accompanied by a marked decrease in the expression of growth-stimulating genes, including IGF-1, GH-1, GHR-1, and CCKA, but not with an inhibitor of GABA_C receptor, TPMPA. Additionally, IGF-1 and IGF-1R expression was impaired in bicuculline and CGP 46381-treated MC3T3-E1 cells, but not in the cells treated with TPMPA. Furthermore, treatment with bicuculline and CGP 46381 significantly downregulated GABA-induced IGF-1 release in MC3T3-E1 cells. These data indicate that GABA stimulates IGF-1 release via GABA_A and GABA_B receptors and leads to growth promotion performance via IGF-1R.

Effects of Siwu decoction on chondrocyte proliferation of growth plate in adolescent rats

ETHNOPHARMACOLOGICAL RELEVANCE

According to traditional Korean medicine theory in which children's growth retardation is attributed to blood deficiency, Siwu decoction (SWD), a representative treatment for blood deficiency, was chosen as a sample.

AIM OF THE STUDY

To evaluate the effects of SWD on chondrocyte proliferation of growth plate in adolescent female rats.

MATERIALS AND METHODS

Female adolescent rats were allocated to one of the following four groups; SWD 100 and 300 mg/kg, recombinant human growth hormone, and vehicle for 4 days. Tetracycline was intraperitoneally injected at 48 h before sacrifice to obtain a band exhibiting fluorescence by binding newly formed bone. Bromodeoxyuridine was injected at day 2-4 to mark proliferating chondrocytes. To evaluate possible mechanisms of SWD, expressions of insulin-like growth factor-1 (IGF-1) and bone morphogenetic protein-2 (BMP-2) in the growth plate were examined by immunohistochemistry.

RESULTS

Treatment with SWD significantly increased the number of BrdU-positive chondrocytes and the new bone formation in the proximal growth plate of tibia compared to the vehicle treated control group. SWD also increased the expression of IGF-1 and BMP-2 in the proliferative and hypertrophic zones of the growth plate.

CONCLUSIONS

SWD 300 mg/kg stimulates chondrocyte proliferation and new bone formation in the growth plate. Immunohistochemical studies indicate that the effects of SWD may be due to upregulation of local IGF-1 and BMP-2 expression in the growth plate, which may be considered as a GH-dependent paracrine-autocrine pathway.

Effects of Phlomis umbrosa Root on Longitudinal Bone Growth Rate in Adolescent Female Rats

This study aimed to investigate the effects of Phlomis umbrosa root on bone growth and growth mediators in rats. Female adolescent rats were administered P. umbrosa extract, recombinant human growth hormone or vehicle for 10 days. Tetracycline was injected intraperitoneally to produce a glowing fluorescence band on the newly formed bone on day 8, and 5-bromo-2'-deoxyuridine was injected to label proliferating chondrocytes on days 8-10. To assess possible endocrine or autocrine/paracrine mechanisms, we evaluated insulin-like growth factor-1 (IGF-1), insulin-like growth factor binding protein-3 (IGFBP-3) or bone morphogenetic protein-2 (BMP-2) in response to P. umbrosa administration in either growth plate or serum. Oral administration of P. umbrosa significantly increased longitudinal bone growth rate, height of hypertrophic zone and chondrocyte proliferation of the proximal tibial growth plate. P. umbrosa also increased serum IGFBP-3 levels and upregulated the expressions of IGF-1 and BMP-2 in growth plate. In conclusion, P. umbrosa increases longitudinal bone growth rate by stimulating proliferation and hypertrophy of chondrocyte with the increment of circulating IGFBP-3. Regarding the immunohistochemical study, the effect of P. umbrosa may also be attributable to upregulation of local IGF-1 and BMP-2 expressions in the growth plate, which can be considered as a GH dependent autocrine/paracrine pathway.

Stories of experiences of care for growth hormone deficiency: the CRESCERE project

AIMS

Growth hormone deficiency therapy is demanding for patients and caregivers. Teams engaged in the clinical management of growth hormone deficiency therapy need to know how families live with this condition, to provide an adequate support and prevent the risk of withdrawal from therapy.

METHODS

Using Narrative Medicine, testimonies from patients, their parents and providers of care were collected from 11 Italian centers. Narrations were analyzed throughout an elaboration of recurring words and expressions.

RESULTS

Although care management and outcomes were considered satisfying in the 182 collected narratives, recurring signals of intolerance among adolescents and the worry of not being well informed about side effects among parents are open issues.

CONCLUSION

Narratives found that communication issues could decrease adherence and influence the physicians' clinical practice.

Response of Indian growth hormone deficient children to growth hormone therapy: association with pituitary size

OBJECTIVE

To ascertain the impact of pituitary size as judged by Magnetic Resonance Imaging (MRI), on response to Growth Hormone (GH) therapy in GH deficient children.

METHODS

Thirty nine children (9.1 ± 2.7 y, 22 boys) with non-acquired GH deficiency (21 Isolated GH deficiency and 18 Combined pituitary hormone deficiency) were consecutively recruited and followed up for one year. Clinical, radiological (bone age and MRI) and biochemical parameters were studied.

RESULTS

Children with hypoplastic pituitary (pituitary height < 3 mm) had more severe height deficit (height for age Z-score -6.0 vs. -5.0) and retardation of skeletal maturation (bone age chronological age ratio of 0.59 vs. 0.48) at baseline as compared to children with normal pituitary heights (p < 0.05 for both). After one year of GH therapy, height for age Z scores and percentage change in height for age Z scores were significantly higher in children with hypoplastic pituitaries (13.8 ± 3.6 and 28.7 % vs. 11.2 ± 4.1 and 21.4 %). Significant co-relation was observed between pituitary height and height for age Z-scores at baseline (r = 0.39, p < 0.05). The predicted adult height using Tanner Whitehouse-2 equations improved from 140.8 to 152.3 cm in children with hypoplastic pituitary when compared to an increase from 145.8 to 153.5 cm observed in children with normal pituitary height (p < 0.05).

CONCLUSIONS

Indian growth hormone deficient children with hypoplastic pituitary respond better to therapy with GH in short term.

Adherence to growth hormone therapy: a practical approach

BACKGROUND

Early detection of suspected poor adherence to growth hormone (GH) therapy is crucial to achieve normal final height in GH-deficient (GHD) patients.

PATIENTS

106 children (73 M, 33 F) with a median age of 10.47±3.48 years (mean±standard deviation score (SDS)) exhibited short stature (-1.76±0.64 SDS) and a delayed bone age (8.68±3.42 years). Severe GHD was found in 28, while partial GHD was seen in 78 cases, with low IGF-I values. Recombinant human GH was administered by daily subcutaneous injection at a dosage of 21 µg/kg in prepubertal and 25 µg/kg in pubertal patients.

RESULTS

Poor adherence was suspected in a number of patients, but clearly demonstrated in only 4 cases with persistent reduced height velocity in spite of a corrected therapeutic regimen. These patients admitted incomplete adherence to GH injections and clinical and anthropometric measurements revealed their poor response to therapy.

CONCLUSIONS

To efficaciously improve adherence in GHD patients, it is mandatory to regularly interview patients; a non-aggressive approach might be utilized to ensure effective communication with patients and their parents.

Effect of one-year growth hormone therapy on body composition and cardio-metabolic risk in Indian children with growth hormone deficiency

Growth hormone (GH) deficiency in children manifests as short stature but is also associated with metabolic disturbances. Paucity of GH is also likely to be associated with increased intima media thickness. Data on body composition (BC) and carotid intima media thickness (cIMT) in children with growth hormone deficiency (GHD) from developing countries are very scarce. Therefore, objectives of present study were to assess effect of 1 year of rhGH therapy on (i) BC and lipid profile (LP) in a cohort of Indian GHD children and (ii) effect on atherosclerotic markers - cIMT in subsample. Anthropometry, BC [% body fat (BF), % lean body mass (LBM), bone mineral content (BMC)] (DXA) and LP were measured in 49 pre-pubertal GHD-children (9.3 ± 3.1 years) at baseline and after 1 year of rhGH therapy. On subset of 20 children, cIMT of right common carotid artery was also measured. Baseline BC parameters were compared with age-gender matched healthy controls (n = 49). At baseline % BF was 23 ± 9 %, LBM was 9 ± 3 kg and BMC was 0.306 ± 0.15 kg in GHD- children; BF was comparable, while lean and bone were less than controls (p < 0.05). Post therapy, significant reduction in fat (15%), and cIMT (7%) and increase in LBM and BMC by 40% and 44%, respectively (p < 0.05) was seen. Our cohort of untreated GHD children had abnormal BC and cIMT as compared to controls. rhGH therapy for 1 year had beneficial effect on BC and cardiovascular risk factors.

The benefits of growth hormone therapy in patients with Turner syndrome, Noonan syndrome and children born small for gestational age

This review will summarize the effects of growth hormone (GH) on height, body composition, bone and psychosocial parameters in children with Turner syndrome or Noonan syndrome and those born small for gestational age. The safety of GH treatment in children with these diagnoses is also reported. Despite the reported efficacy and safety of GH in these indications, however, not all children achieve their target height potential, due in some part to poor adherence to GH therapy regimens; indeed up to 50% of children are less than fully compliant with treatment. With this in mind the present and future administration of GH therapy is discussed with respect to advances being made in the presentation of GH for injection and advances in GH injection devices. It is hoped that such progress, aimed at making the administration of GH easier and less painful for the patient will improve treatment adherence and outcome benefits.

Ease of use and acceptability of a new pen device for the administration of growth hormone therapy in pediatric patients: an open-label, uncontrolled usability test

BACKGROUND

Recombinant human growth hormone (GH) is used for the treatment of several conditions associated with growth retardation and metabolic dysfunction. These patients are typically diagnosed and treated from childhood, and treatment adherence in children might be problematic. To potentially improve treatment adherence in children who self-inject GH, it is important that devices for the administration of GH are simple to learn to use, simple to use, and well accepted by patients and their parents or guardians.

OBJECTIVE

This study compared the usability and acceptability of the Norditropin FlexPro pen and NovoFine needles (Novo Nordisk A/S, Bagsvaerd, Denmark) for the administration of GH in pediatric patients with GH deficiency (GHD).

METHODS

Patients aged 10 to <18 years with GHD and who were receiving daily treatment with selfinjectable GH were included in this open-label, uncontrolled usability test. Patients used the Norditropin FlexPro pen and NovoFine G32 needles to inject test medium into an injection pad; this test was repeated. For the assessment of patients' acceptance of the device, patients completed a 21-item questionnaire regarding pen performance before and during injection.

RESULTS

Seventy patients participated in the study (mean age, 14 years; 67% male; 23% left-handed). No significant differences in demographic characteristics (age, sex, duration of treatment with GH, current device used, and left- or right-handedness) were found between boys and girls, younger and older children, or children who had been receiving short-term (months) or long-term (years) GH treatment. Sixty-eight patients (97%) rated attachment of the needle, priming the device, dialing up the dose, and reading the scale on the device as very easy or quite easy. A total of 99% of patients rated injection of their usual dose and of a 4-mg dose as very easy or quite easy, and pushing the dose button as very easy or quite easy as well as very comfortable or quite comfortable. All of the patients rated hearing the click while performing the injection as very easy or easy. Overall, 64% of patients indicated a preference for the Norditropin FlexPro pen over the device they were currently using.

CONCLUSIONS

In this preliminary usability test in pediatric patients, the Norditropin FlexPro pen was perceived as reliable and easy to use and was well accepted. There was also a high level of comfort that GH had been injected properly and that the correct dose had been delivered among the children and adolescents with GHD who participated in the study.

Impact of Absorption and Transport on Intelligent Therapeutics and Nano-scale Delivery of Protein Therapeutic Agents

The combination of materials design and advances in nanotechnology has led to the development of new therapeutic protein delivery systems. The pulmonary, nasal, buccal and other routes have been investigated as delivery options for protein therapy, but none result in improved patient compliances and patient quality of life as the oral route. For the oral administration of these new systems, an understanding of protein transport is essential because of the dynamic nature of the gastrointestinal tract and the barriers to transport that exist.Models have been developed to describe the transport between the gastrointestinal lumen and the bloodstream, and laboratory techniques like cell culture provide a means to investigate the absorption and transport of many therapeutic agents. Biomaterials, including stimuli-sensitive complexation hydrogels, have been investigated as promising carriers for oral delivery. However, the need to develop models that accurately predict protein blood concentration as a function of the material structure and properties still exists.

Observations of nonadherence to recombinant human growth hormone therapy in clinical practice

BACKGROUND

The effectiveness of all prescribed treatments is contingent on patient adherence. The reported levels of adherence to recombinant human growth hormone (r-hGH) therapy are highly variable, but it has been suggested that nonadherence might be as high as 36% to 49%.

OBJECTIVES

This commentary discusses the factors that affect long-term adherence to injection treatment, of which r-hGH therapy is a particular challenge. It also explores potential strategies to improve adherence to injection treatments in clinical practice.

METHODS

The opinion of the authors was validated and supported by published literature. A PubMed literature search was conducted in November 2006, identifying English-language articles containing key terms growth hormone, adherence, and compliance.

RESULTS

This study found that factors associated with poor adherence to injection treatments include patients' lack of understanding of their disease, patient age, chronicity of the disease, complex treatment regimens, and insufficient information on the implications of nonadherence. Strengthening the patient-physician relationship by providing the patient with a clear understanding of his/her disease and the benefits of adherence, making improvements in injection devices, and eliminating subjective illness concepts, might increase adherence to SC injection treatments, thereby reducing increasing health care costs associated with nonadherence.

CONCLUSIONS

Poor adherence to r-hGH therapy has a dual effect, in that it leads to reduced efficacy out-comes and increased health care costs. Implementing strategies to improve adherence with injection treatment might be of particular clinical benefit to patients undergoing r-hGH therapy.

The herbal medicine Tokishakuyakusan increases fetal blood glucose concentrations and growth hormone levels and improves intrauterine growth retardation induced by N(omega)-nitro-L-arginine methyl ester

N(omega)-Nitro-L-arginine methyl ester (L-NAME) induces a pre-eclampsia-like syndrome in pregnant rats. We have previously reported the anti-hypertensive effects of several Japanese traditional (Kampo) medicines in this model, and one of these, Tokishakuyakusan (TS), also improved intrauterine growth retardation (IUGR). In the present study, we characterized the effect of TS on IUGR. TS administration reversed the decrease in fetal body weight and fetal blood glucose concentration induced by the infusion of L-NAME. Growth hormone (GH) levels in the fetal blood, which were decreased by L-NAME infusion, were also significantly elevated by TS; however, levels of GH releasing hormone (GHRH) and insulin-like growth factor I (IGF-I) were unchanged and only slightly changed, respectively. Treatment with L-NAME with or without TS had no apparent effect on GH, GHRH, and IGF-I levels of dams. In an immunocytochemical study, the number of GH-positive cells in the fetal pituitary gland was significantly increased in TS-treated rats. These data suggest that enhanced proliferation of somatotrope cells of the pituitary gland and the resultant increase in GH secretion in the fetus may be involved in the improvement of IUGR by TS.