人参皂甙对小脑生长锥影响的体外培养观察

自吉林人参根部制备的总皂甙(Rx),按每毫升培养液含50,100,200μg的浓度,对新生(P-O)B_6C_3小鼠的小脑进行Maximow器官——组织型培养,总数达120片。在体外培养第2,3,5天分别在相差显微镜下进行活体观察,对生长锥的长度和密度作进一步的观察和测量,同时结合神经染色和扫描电镜的观察与记录,结果显示实验组在生长锥的生长趋势较对照组明显,尤以100μg/ml组最为显著,具有统计学意义。本研究结果提示人参皂甙对神经组织的生长和神经网络的建立具有促进作用。     

Growth characteristics of human lens epithelial cells in culture

The effect of different concentrations of fetal calf serum (FCS) on the proliferative capacity of human and bovine lens epithelial cells in culture was evaluated. The effect of donor age on the maximum number of passages achieved using thirty eight individual cultures was also studied. The donor ages ranged from 1–88 years. Fifteen percent FCS was found to be the optimum concentration for both human and bovine cells. The two cell types demonstrated very similar responses across the spectrum of concentrations used. Correlation analysis revealed a significant (p < 0.05) negative correlation between donor age and maximum number of cell passages achieved.     

Alcohol Inhibits Epidermal Growth Factor-Stimulated Progesterone Secretion from Human Granulosa Cells

In this study, luteinized human granulosa cells (GC) obtained during in vitro fertilization procedures were used as a model system to evaluate the effects of ethanol (EtOH), a well-known reproductive toxin, on epidermal growth factor (EGF) and gonadotropin-stimulated steroidogenesis. Our results demonstrate that the basal progesterone (P₄) and estradiol (E₂) secretion by human GC in vitro was dependent on the ovarian stimulation protocol. EGF significantly enhanced P₄, but not E₂, secretion in human GC from clomiphene citrate (CC), human menopausal gonadotropin (hMG), and hMG/gonadotropin-releasing hormone agonist (GnRH-a)-treated patients. The effects of EGF plus luteinizing hormone (LH) were additive in cells from the CC group, but less than additive in hMG and hMG/GnRH-a groups. EtOH at 20 mM or more inhibited EGF stimulated P₄ secretion in human GC from all three patient groups. EtOH inhibited P₄ secretion stimulated by EGF and LH cotreatment in the CC and hMG/GnRH-a groups, but not in human GC from the hMG-treated patients. These results suggest that basal and EGF or LH-stimulated P₄ secretion by human GC, as well as the effects of EtOH, are profoundly influenced by the follicle's hormonal milieu.     

Follow up of growth and steroids in premature adrenarche

In a follow up study of 34 patients with premature adrenarche we examined serum adrenal androgen levels and growth. The majority (28/34) showed an upward bend in the growth curve which, at the mean age of 2.3 years, preceded other signs of adrenarche on average by 3.8 years. Pubertal growth spurt was missing or reduced in 50% of the patients (8/16), however, final height did not differ from that expected from parental heights. Adrenal androgens did not remain elevated at adolescence. The mean age at menarche for all the girls was 0.5 years younger than in the general population.Conclusion Our findings imply that premature adrenarche may start earlier than previously recognized. Compared to ordinary growth these children seen to use a greater part of their potential for adult height already at that early age.     

Ask the expert

I am following a boy who, 5 years after transplantation, is growing reasonably, but well below the third percentile. He is 10 years old, has a serum creatinine of 80 mol/l, and is moderately hypertensive (well controlled by atelonol). His parents accept his growth retardation, as does he, apparently. Should I start this boy on growth hormone or can I wait?     

Growth hormone and renal osteodystrophy: a case report

A 14-year-old male with end-stage renal disease on hemodialysis was treated with recombinant growth hormone for growth retardation. He developed severe renal osteodystrophy, which responded only to the discontinuation of growth hormone. Received January 24, 1997; received in revised form August 19, 1997; accepted August 22, 1997     

An approach to protein restriction in children with renal insufficiency

Children with mild to moderate renal insufficiency may be at an increased risk for developing glomerulosclerosis and subsequent renal failure. Low protein diets (LPD) have been shown to delay the progression of renal insufficiency in laboratory animals and may be of benefit in adult humans. The nutritional costs of a LPD in adults are reportedly minimal. We review the protein and caloric requirements of growing children and discuss the potential harmful effects and benefits of an LPD in this population. We also discuss dietary adherence and the difficulty of designing an LPD for children. We conclude that the protein content of a typical American diet can safely be reduced to, but not below, the recommended daily allowance for protein if diets are carefully planned, patients and their parents extensively counseled, and if dietary supplements are given to help meet the caloric and vitamin-mineral nutrient needs of growing children. In addition, ongoing nutritional assessment, counseling, and frequent monitoring of growth, diet and biochemical indicators of protein status are essential for maintaining the health of these children.     

Mechanism of action of parathyroid hormone-induced proteoglycan synthesis in the growth plate chondrocyte

In the growth plate chondrocyte, parathyroid hormone (PTH) stimulates phosphoinositol 4,5 bisphosphate (PIP2) degradation, which results in the rapid production of inositol (1,4,5) triphosphate (IP3). IP3 induced the release of calcium from an intracellular store, which caused a rapid increase in the cytosolic ionized calcium concentration. Parathyroid hormone also induced a 30-50% increase in proteoglycan synthesis. Phorbol esters, which pharmacologically activate protein kinase C, resulted in a 70-80% increase in proteoglycan synthesis. Treatment of the chondrocytes with retinoic acid (0.2 microM) inhibited the parathyroid hormone and phorbol ester-induced increase in intracellular ionized calcium and the increase in proteoglycan synthesis. From this data we postulate that the stimulation of proteoglycan synthesis in growth plate chondrocytes by PTH is mediated by the breakdown of membrane phosphoinositides, which results in the production of IP3 and an increase in ionized intracellular calcium. It is suggested that the degradation of membrane phosphoinositides also results in production of diacylglycerol and, thereby, an activation of protein kinase C, which has a large stimulatory effect on proteoglycan synthesis. The increase in cytosolic calcium most likely acts synergetically with diacylglycerol to activate protein kinase C. Retinoic acid blocks the effect of PTH and phorbol ester-induced proteoglycan synthesis and may act through the inhibition of protein kinase C. The overall effect of PTH on the growth plate chondrocyte appears to be a stimulation of proteoglycan synthesis that is mediated by the degradation products of membrane phosphoinositides.     

Modulation of TNF-α mRNA production in rat C6 glioma cells by TNF-α, IL-1β, IL-6, and IFN-α: In vitro analysis of cytokine-cytokine interactions

Cytokines regulate the expression of other cytokines in the centrally derived rat C6 glioma cell line. However, the modulation of tumor necrosis factor-α (TNF-α, a pivotal proinflammatory cytokine) in C6 cells is unknown. Here we investigated the expression of TNF-α mRNA in C6 glioma cells in response to TNF-α, interleukin-1β (IL-1β), IL-1 receptor antagonist (IL-1Ra), interleukin-6 (IL-6), and interferon-α (IFN-α). The data show that (1) IL-1β induced a significant upregulation of TNF-α mRNA; (2) the effect of IL-1β on TNF-α mRNA expression was completely blocked by the concomitant application of IL-1Ra, which suggests specificity of IL-1β action through the IL-1 signaling receptor; (3) no detectable modulation of TNF-α mRNA expression was observed with the individual applications of TNF-α, IL-6, or IFN-α; (4) the concomitant treatments of TNF-α + IL-1β or TNF-α + IL-1β + IL-6 strongly upregulated TNF-α mRNA expression, whereas the concomitant application of TNF-α + IL-6 or IL-1β + IL-6 induced a moderate increase; and (5) IFN-α significantly attenuated induction of TNF-α mRNA by TNF-α + IL-1β + IL-6. Thus, IL-1β, TNF-α and IL-6 interact to upregulate TNF-α mRNA expression synergistically, and IFN-α acts as an inhibitory cytokine in C6 glioma cells. These findings also suggest that the rat C6 glioma cell line may be used as an in vitro model to characterize cytokine-cytokine interactions.     

The influence of growth hormone monotherapy and growth hormone in combination with oxandrolone or testosterone on thyroxid hormone parameters and thyrxine binding globulin in patients with Ullrich- Turner syndrome

 Administration of human growth hormone (GH) has yielded conflicting results concerning its role on thyroid function in patients with Ullrich-Turner syndrome. Therefore, we investigated the course of thyroid hormone parameters and thyroxin binding globulin in relation to GH therapy, IGF-I and additional oxandrolone-(Ox) or testosterone (T) treatment in 20 patients with Ullrich-Turner syndrome. During the 1st year the patients received only GH. There was no change in T4, fT4, and TSH levels, T3 increased significantly (P <  0.01) after 6 and 12 months, resulting in a higher T3/T4 ratio. TBG (P < 0.05) and IGF-I (P < 0.01) increased after 6 months and remained elevated at 12 months. A significant positive correlation was found between the change of T4 and TBG after 6 months (r = 0.47, P < 0.05) and after 12 months (r = 0.69, P < 0.005). Thirteen patients were further investigated after addition of an anabolic compound; 7 received Ox (0.0625 mg/kg/day po) and 6 low dose T (5 mg i.m. every 14 days). Chronological age was comparable in these groups (10.7 ±  2.7 vs 10.7  ± 3.6 years). After 6 months of combination therapy with Ox, T4, T3 and TSH decreased. As T4 and T3 showed a parallel decrease the T3/T4 ratio remained elevated. TBG declined after 6 and 12 months (P < 0.05), while IGF-I showed a further increment (P < 0.05). There was no correlation between the changes in T4 and IGF-I, TSH and TBG, respectively. In the T-treated group only IGF-I increased (P < 0.05) to the same extent as in the Ox-treated patients, whereas the thyroid parameters did not change. Conclusion The observed changes in thyroid hormone and TBG levels in the Ox group were not mediated by GH or IGF-I. The Ox-induced TBG decrease might be linked to altered pancreatic functions regulating carbo-hydrate metabolism. Received: 22 April 1996 / Accepted: 1 August 1996