Endocrine effects on the growth, development and function of the eye

A cohort of hormonal signals affects the function of the eye in providing eyesight. From the early days of growth, endocrine mechanisms guide the young eye's development. Later on in life, hormonal interactions play an important role in maintaining proper vision and continue to affect the eyes in pregnancy, as well as in aging. The purpose of this article is to review the effects of the endocrine system on the eye. Current knowledge about hormonal interactions that play a role in the growth and development of the eye will be discussed separately for each of the hormones known to be involved.     

Neonatal hypoxia in the rat: effects on exocrine pancreatic development

BACKGROUND: Glucocorticoids profoundly affect pancreatic development during the suckling period. Increases in circulating glucocorticoids during exposure to hypoxia may alter the normal pattern of pancreatic enzyme development. METHODS: Rats were exposed to hypoxia from birth to 7 days (suckling) or from 28 to 35 days of age (weaned at day 21). RESULTS: Hypoxia in neonatal rats (0-7 days) led to decreased pancreatic weight, and trypsin, lipase, and amylase activity compared with normoxic controls. In contrast, rats exposed to hypoxia from 28 to 35 days of age had decreased lipase activity but no change in other pancreatic parameters. Two weeks after hypoxia (0-7 days) pups were returned to normoxia, and their body weights remained smaller than the age-matched, previously normoxic controls. Pancreatic enzyme activities were decreased in the group recovering from hypoxia compared with controls. Recovery of enzyme activities was observed 3 weeks after hypoxic rats were returned to normoxia. Normoxic pups were given dexamethasone to simulate the hyperglucocorticoid state in hypoxia at 7-day olds. Dexamethasone administration led to decreased body weight, but increased pancreatic weight and enzyme activity compared with normoxic, age-matched controls. CONCLUSIONS: Hypoxia in newborn rats delays the maturation of pancreatic exocrine enzymes. The mechanism is not related to increased serum glucocorticoids.     

生长激素和胰岛素样生长因子与小儿免疫系统发育的研究

目的研究生长激素（ＧＨ）和胰岛素样生长因子（ＩＧＦｓ）对小儿免疫系统发育的调节作用及其机制。方法采用放射受体竞争结合、核酸分子杂交、免疫组化等方法，从蛋白质和（或）基因表达水平系统观察了ＧＨ及其受体（ＧＨＲ）、ＩＧＦ多肽（ＩＧＦＩ、Ｉ）、受体（ＩＧＦＩＲ、ＩＲ）和结合蛋白（ＩＧＦＢＰ１６）在小儿外周血淋巴细胞（ＰＢＬ）、胸腺和淋巴结的表达、分布与调节。结果ＧＨＲ在ＰＢＬ的表达呈年龄相关的变化；胸腺、淋巴结和ＰＢＬ都有ＧＨ合成细胞，且ＧＨ缺乏患儿与正常人无异；ＩＧＦｓ多肽、受体和结合蛋白基因在儿童胸腺和淋巴结均有不同水平的表达，提示它们在免疫器官局部以自分泌或旁分泌的形式产生和发挥作用。结论ＧＨＩＧＦ对于影响和调节小儿免疫系统发育具有重要意义     

Serum concentrations of the type I and III procollagen propeptides as biochemical markers of growth velocity in healthy infants and children and in children with growth disorders

The reproducibility and specificity of a new, rapid, simple RIA for measuring the concentration of the soluble carboxypropeptide of type I procollagen (PICP) in serum was confirmed. Serum PICP was determined in 442 healthy Caucasian subjects ranging in age from 3 wk to 18 y. Highest PICP values (mean +/- SD: 2200 +/- 350 micrograms/L) occurred in infants less than 3 mo of age, falling by 70% at 2 y and by an additional 10% at 4 y. There was no significant change in serum PICP between 4 and 16 y of age (330 +/- 130 micrograms/L), but a decrease to adult levels of less than 160 micrograms/L occurred by 18 y. In 76 children with growth disorders, serum PICP was related to linear growth velocity (p less than 0.001), although there were no significant differences in PICP among the 38 children with growth hormone insufficiency, the 21 short children with no endocrinologic abnormality, or the 17 tall children. All 15 prepubertal children treated with growth hormone for 3 mo showed significant increases in both growth velocity and serum PICP, with a significant relationship (p less than 0.01) between the degree of increases. The rise in serum PICP at 3 mo (but not baseline PICP values) predicted the increase in growth velocity after 1 y of treatment. Similar changes were observed in the concentration of the aminopropeptide of type III procollagen, except that serum aminopropeptide of type III procollagen showed a definite increase during puberty and a wider spread of values in growth disorders. We conclude that measuring serum PICP by the new, reproducible assay reflects height velocity in prepubertal children and may be a useful biochemical means of monitoring growth rates.     

A possible role of prolactin on growth and maturation of the gut during development in the rat

The growth and maturation of the gastrointestinal tract during development is influenced by diverse genetic and growth factors. Since prolactin is abundant in amniotic fluid and breast milk, we hypothesized that it may also affect gut development. The effect of prolactin on thymidine incorporation and tissue alkaline phosphatase, maltase and lactase activity was studied on jejunal explants from fetal, newborn and 2 week-old rats. The results were compared with the effects of epidermal growth factor (EGF) under identical experimental conditions. Prolactin induced a significant increase in proliferation and a two- to threefold increase in maltase and alkaline phosphatase activity of the newborn explants. The effect of prolactin in this group compared to that of EGF was significantly greater with respect to proliferation, and almost identical with respect to the hydrolases studied. These results suggest that prolactin might have a role in the process of growth and maturation of the gut mucosa during ontogeny.     

产前感染对新生大鼠肺发育的影响

目的 动态观察产前炎症暴露后新生大鼠肺形态及炎症细胞表达变化,探讨产前感染对新生大鼠肺发育影响的病理机制.方法 Wistar孕鼠按照随机数字表分为实验组和对照组,分别于孕19d和20d腹腔注射脂多糖(lipopolysaccharide,LPS)2.5mg/kg和等量生理盐水,足月自然分娩后,于日龄1d、3d、7d、14d、21 d及28 d两组分别取8只新生鼠,麻醉处死后取肺组织,以髓过氧化物酶(myeloperoxidase,MPO)和CD68作为中性粒细胞及巨噬细胞标志物,计数炎症细胞数量、图像分析测定肺泡数量、肺泡面积占组织面积比例、肺泡间隔厚度.结果 随日龄增加,新生鼠肺泡数量、肺泡占组织面积比例逐渐增加,肺泡间隔变薄,实验组炎症细胞数量逐渐减少.日龄1d、3d、7d及14d,实验组平均肺泡数量(88、89、102、127,单位:个/mm2)明显少于同日龄对照组(105、109、123和156,单位:个/mm2),P分别为0.024、0.009、0.013和0.004;日龄1d、3d和7d,实验组肺泡占组织面积比例(0.552、0.603和0.533)明显大于同日龄对照组(0.478、0.485和0.404),P分别为0.003、0.001和0.000;日龄1d及3d,实验组肺泡间隔厚度(12.30和10.75,单位:μm)明显小于同日龄对照组(17.13和16.13,单位:μm),P分别为0.000和0.000.日龄1d、3d、7d及14d,实验组中性粒细胞数量(681、582、393和379,单位:个/mm2)明显多于同日龄对照组(164、211、145和179,单位:个/mm2),P分别为0.000、0.000、0.000及0.003;日龄1d、3d及7d,实验组巨噬细胞数量(613、578和337,单位:个/mm2)明显多于同日龄对照组(170、182和127,单位:个/mm2),P分别为0.000、0.000和0.000.结论 产前炎症暴露使新生大鼠肺泡增大,数量减少,炎症细胞增多.随着新生鼠日龄的增加,肺泡发育接近正常.     

Influence of epidermal growth factor on fetal rat lung development in vitro

Epidermal growth factor (EGF) has been shown to enhance cell multiplication or differentiation in a number of developing tissues. We have examined the effects of this growth factor on the biochemical development of explants of fetal rat lung, cultured in serum-free medium for 48 h. EGF enhanced the rate of choline incorporation into phosphatidylcholine and disaturated phosphatidylcholine in a dose dependent fashion. Half maximal stimulation occurred at a concentration of 1.0 nM, similar to the Kd for EGF binding to rat lung cell membranes. There was also significant stimulation of acetate incorporation into all phospholipids, particularly phosphatidylglycerol (539%), and increased distribution of radioactivity from acetate in this phospholipid fraction. Exposure to EGF stimulated PC synthesis in 18- and 19-day explants (term is 22 days) whereas maximal enhancement of DNA synthesis occurred after this time. This sequence differs from that observed during early embryonic development when EGF initially enhances cell multiplication. An additive interaction with regard to enhancement of PC synthesis was observed with EGF and thyroid hormone, but not EGF and dexamethasone. EGF had no effect on the activity of the enzymes of the choline incorporation pathway of phosphatidylcholine synthesis or on the activity of enzymes involved with acidic phospholipid synthesis. Fetal lung EGF content and EGF binding capacity were not increased by glucocorticoid treatment and similarly glucocorticoid binding capacity was not increased by EGF. These data indicate that EGF enhances fetal rat lung phospholipid synthesis in a dose-dependent manner and suggest that this is a direct effect on the lung tissue mediated by specific receptors.     

Perinatal development of the rat kidney: apoptosis and epidermal growth factor

ABSTRACT  Localization of apoptotic cells in the kidney of perinatal rats was examined by the terminal deoxynucleotidyl transferase–mediated d–UTP–biotin nick end labeling (TUNEL) method and electron microscopy. Perinatal changes in the percentage of kidney cells with DNA fragmentation were determined by flow cytometric analysis. Through observation of two successive sections, the relationship between the localization of the epidermal growth factor receptor (EGFR) positive cells and TUNEL positive cells in the kidney was determined. From fetal day 18 to neonatal day 5, TUNEL positive cells were noted in immature glomeruli, collecting ducts and interstitium. Electron microscopically, chromatin condensed nuclei and apoptotic bodies were seen in the same tissue component as the TUNEL positive cells. The percentage of DNA fragmented cells significantly increased from fetal days 18 to 20 and significantly decreased from fetal days 20 to 22, while they still remained low in the neonatal period. The TUNEL positive cells in immature glomeruli and collecting ducts were not reactive to the EGFR antibody. The TUNEL positive cells were not observed in the proximal tubular cells, which were positive to EGFR antibody. These results indicate that apoptotic cells are present in the kidney throughout the perinatal period in the rat and that EGF plays an important role in perinatal development of the rat kidney.     

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??Abstract?? Objective??To evaluate the value of biochemical markers in the diagnosis of biliary atresia ??BA?? and neonatal intrahepatic cholestasis caused by citrin deficiency ??NICCD??. Methods??Totally 77 infants in hospital with infantile hepatitis syndrome ??IHS?? were enrolled from December 1?? 2008 to March 31?? 2009. Totally 27 patients were diagnosed as having BA and 11 with NICCD. Biochemical markers were compared between groups including alanine transaminase ALT?? aspartate transaminase AST ?? alkaline phosphatase ALP?? γ-glutamyl transpeptidase γ-GT?? total bilirubin TB?? direct bilirubin DB?? total bile acid TBA?? total cholesterol TC??to compute ALT/AST??ALP/γ-GT and glucose GLU?? lactic acid LAC?? total protein TP?? albumin ALB in the NICCD group. The data were analyzed by T test and ROC curve with SPSS10.0. Results??γ-GT was significantly elevated in the infants with BA when compared to non-BA group ??P = 0.003???? cut-off point was 332.5U/L. ALP/γ-GT was significantly lower in the patients with BA??and cut-off point was 1.93. The infants with NICCD had significantly different biochemical markers including GLU?? LAC?? TP?? ALB?? ALT/AST and γ-GT. Conclusion??Biochemical markers could be considered as complementary diagnosis of BA and NICCD for differentiating infants with IHS.     

Ciprofloxacin treatment in preterm neonates in Bangladesh: lack of effects on growth and development

BACKGROUND: Quinolone-induced arthropathic toxicity in weight-bearing joints observed in juvenile animals during preclinical testing has largely restricted the routine use of ciprofloxacin in the pediatric age group. As histopathologic, radiologic and magnetic resonance imaging monitoring evidence has gathered supporting the safety of fluoroquinolones in children, many pediatricians have started to prescribe quinolones to some patients on a compassionate basis. OBJECTIVE: The objective of this study was to ascertain the safety of ciprofloxacin in preterm neonates <33 weeks gestational age treated at Dhaka Shishu (Children) Hospital in Bangladesh. METHODS: Long-term follow up was done to monitor the growth and development of preterm infants who were administered intravenous ciprofloxacin in the neonatal period. Ciprofloxacin was used only as a life-saving therapy in cases of sepsis produced by bacterial agents resistant to other antibiotics. Another group of preterm neonates with septicemia who were not exposed to ciprofloxacin, but effectively treated with other antibiotics and followed up, were matched with cases for gender, gestational age and birth weight and included as a comparison group. Forty-eight patients in the ciprofloxacin group and 66 patients in the comparison group were followed up for a mean of 24.7 +/- 18.5 months and 21.6 +/- 18.8 months, respectively. RESULTS: No osteoarticular problems or joint deformities were observed in the ciprofloxacin group during treatment or follow up. No differences in growth and development between the groups were found. CONCLUSIONS: Ciprofloxacin is a safe therapeutic option for newborns with sepsis produced by multiply resistant organisms.     

Vitamin A and biochemical development. I. Effect of postnatal excess vitamin-A administration on lipogenesis in various organs of the rat

The effect of the administration of an excessive dose of vitamin A (1,000 IU) to rat pups on the 4th, 6th, 8th and 10th days of age was studied on the contents of saponifiable (total fatty acids) and non-saponifiable (cholesterol) lipids. Lipogenesis and cholesterogenesis was studied with the help of sodium-1-14C-acetate incorporation. The heart, liver and lung showed impaired lipogenesis while in the brain only cholesterogenesis was affected.     

Bone mass, biochemical markers and growth in children with chronic kidney disease: a 1-year prospective study

AIM: This study was designed to investigate bone mineral density (BMD), growth parameters and biochemical markers in children with chronic kidney disease (CKD). METHODS: Sixteen patients, 4-18 years, with CKD were prospectively followed for 1 year. Auxological data, body composition, BMD by dual-energy X-ray absorptiometry, bone age, bone turnover markers, vitamin D, parathyroid hormone (PTH), leptin, osteoprotegerin, insulin-like growth factor-I (IGF-I) and IGF binding protein-3 were measured. A questionnaire regarding bone health and diet was also performed. RESULTS: Delayed bone age was observed (n = 11) and the BMD Z-scores for total body were below zero in seven patients. However, total body BMD (TBBMD) increased in 12 patients. Most patients had increased osteocalcin and carboxy-terminal telopeptide of type I collagen, but normal alkaline phosphatase, type I procollagen intact amino-terminal propeptide and tartrate-resistant acid phosphatase 5b. Ten patients had increased PTH. Most children had normal levels of leptin, osteoprotegerin, IGF-I and IGFBP-3. Leptin, at baseline, correlated with differences in TBBMD over 1 year. CONCLUSIONS: Only seven (44%) had negative Z-scores and TBBMD increased over 1 year. Bone markers at baseline did not predict the longitudinal changes in BMD.     

Perinatal development of the rat kidney: proliferative activity and epidermal growth factor

The immunolocalization of proliferating cell nuclear antigen (PCNA), epidermal growth factor (EGF) and its receptor (EGFR) was examined in the perinatal rat kidney. As the index of proliferative activity, PCNA-positive cell ratios in glomeruli and proximal tubules were determined. The PCNA-positive ratios in both glomeruli and proximal tubules decreased significantly during the perinatal period and tended to decrease as the glomerular developmental stage proceeded as well. PCNA-positive cells were seen predominantly in the nephrogenic zone of the kidney throughout the period examined. They were noted in the collecting ducts of the nephrogenic zone and were rarely seen in those of the central zone of the kidney. On the other hand, PCNA-positive cells were noted in the straight portion of the proximal tubules and were rarely seen in the convoluted one. EGF-positive cells were seen in the proximal tubules, distal tubules and collecting ducts, though EGF-positive cells in the proximal tubules decreased after birth. EGFR-positive cells were seen along the entire length of the proximal tubules and collecting ducts as well as in immature glomeruli, not in mature ones. These results indicate that marked cell proliferation occurs in the collecting ducts in the peripheral area and in the proximal tubules in the central area of the kidney, that the proliferative activity decreases with age during the perinatal days and that EGF plays an important role in the proliferation of glomerular cells, and in both proliferation and maturation of the cells in the proximal tubules and collecting ducts.