上海市婴幼儿血铅水平与体格发育的关系

目的探讨低水平铅暴露对儿童体格发育的影响。方法在上海市5个区县30所托幼机构,对1969名儿童进行了血铅水平的流行病学调查和体格发育等指标测量,并根据儿童身高、体重、头围和胸围计算其Z标准分,然后与血铅水平进行相关分析和逐步回归分析。结果上海市儿童血铅水平几何均数为0．400μmol／L,≥0．483μmol／L的比例为37．8％,血铅水平的几何均数与儿童身高、体重及头围的Z标准分呈显著的负相关。结论低水平铅暴露对上海市婴幼儿的体格发育可能具有不利影响。     

国产生长激素治疗生长激素缺乏症的疗效观察

了解国产人生长激素（ｈＧＨ）的治疗效果。方法：对１５例未经生长激素治疗的生长激素缺乏症（ＧＨＤ）病人（均经精氨酸和可乐宁两项生长激素激发试验明确诊断,生长激素峰值均小于 １０ μｇ／Ｌ）应用国产分泌型基因重组人生长激素（ｒｈＧＨ）进行治疗,剂量为０．１ｕ／（ｋｇ·ｄ）睡前脐周皮下注射,治疗时间６个月。结果：１５例ＧＨＤ病人６个月身高平均增长（６．３４±０．９４）ｃｍ,生长速度由治疗前的（３．３３±０．４９）ｃｍ／年增加到治疗后的（１２．６８±１．８６）ｃｍ／年。结论：国产人生长激素治疗效果达到国外同类产品水平,而价格仅为进口产品的１／６左右。可安全有效地用于治疗ＧＨＤ身材矮小病人。     

The effect of growth hormone on the growth failure of chronic renal failure

To investigate the effects of growth hormone (GH) on the reversal of growth failure in uremia, recombinant human GH (rhGH) was administered to rats with chronic renal failure (CRF). The dosage of rhGH was 3 IU/day (i.p.) for 13 days after the induction of CRF by 5/6 nephrectomy. Animals were classified into four groups: untreated nephrectomized rats (NX,n=40), GH-treated nephrectomized rats (NX+GH,n=18), sham-operated rats fed ad libitum (SHAMAL,n=27), and sham-operated rats pair-fed with 10 NX rats (SHAMPF,n=10). NX and NX+GH rats developed a similar and moderate degree of CRF, serum urea nitrogen being (mean±SEM) 49±3 and 54±4 mg/dl, respectively, compared with 16±4 and 19±0 mg/dl in SHAMAL and SHAMPF groups. Weight (56.0±3.3 g) and length (3.5±0.1 cm) gains of NX rats were lower than those of SHAMAL rats (94.2±4.0 g,P<-0.0001 and 4.1±0.2 cm,P<-0.01). Growth of the SHAMPF group and the matched NX rats was not significantly different. Weight (56.2±5.0 g) and length (3.4±0.2 cm) gains of NX+GH and NX rats were similar, the beneficial effect of GH therapy on growth being observed in only those animals with more severe degrees of uremia. This growth-promoting action resulted from greater food efficiency and not from stimulated food intake. The hypercholesterolemia seen in NX rats, 81±2 mg/dl versus 55±3 mg/dl in SHAMAL (P0.0001), was not increased in the NX+GH group, 87±3 mg/dl. There was a positive and significant correlation between serum cholesterol and serum urea nitrogen values in NX and NX+GH animals. This study suggests that growth impairment of mild CRF is mainly due to malnutrition and is refractory to GH administration. GH therapy improves the growth rate of animals with advanced CRF without aggravating their lipid abnormalities.     

Body mass index percentiles among adolescent girls living in Edirne, Turkey

BACKGROUND: Body mass index (BMI) is the simplest way to measure obesity; therefore, it is chosen by many authorities as a screening method for adolescent obesity. Body mass index is positively correlated with the complications of childhood and adolescent obesity, such as hypercholesterolemia, insulin resistance, hyper-tension and long-term development of cardiovascular diseases. The aim of the present study was to produce percentile curves for bodyweight, height and BMI in a representative sample of adolescent girls living in urban and rural areas of Edirne, Turkey, and to compare these percentile curves with curves from other countries. METHODS: The present study was a cross-sectional study, including a representative sample of 1687 adolescent girls from rural and urban areas of Edirne, who were evaluated between May and July 2001. Bodyweight and height were measured using standard procedures. Body mass index (kg/m2) was calculated as the ratio of bodyweight to body height squared. Smoothed percentiles for these variables were calculated using polynominal regression models. Crude weight, height and BMI percentile values, as well as smoothed percentile curves are presented. RESULTS: Body mass index, weight and height reference curves for adolescent girls were produced. When we compared the BMI values of subjects in the present study with those of other countries, 85th and 95th percentiles of BMI in the present study were found to be generally lower than those for other ethnicities. CONCLUSION: Our findings show ethnic differences in BMI among adolescent girls. It will be usefull for each country to produce its own BMI percentiles.     

Reference Data of Vertebral Morphometry by X-ray Absorptiometry (MXA) in Argentine Women

Anterior, middle, and posterior heights and A/P and M/P ratios were determined from T5 to L4 in 111 normal Caucasian Argentine women from 20 to 70 years of age using dual energy X-ray absorptiometry (DXA) densitometry (Expert XL). Scanning time was less than 1 minute and the semiautomatic analysis requires ∼5 minutes. The precision error for the measurements ranged from 2.2% to 4.6%. The absolute precision error for heights was 0.6 mm. The vertebral bodies tended to be significantly larger in younger women than older women, especially for anterior and middle heights and the A/P and M/P ratios of the mid-thoracic vertebrae (T6–T10). There were no significant differences between pre- and postmenopausal women in the lumbar vertebral heights. It does not appear that this was a cohort effect because stature was identical in both age groups, and there was no age difference in posterior height. The Expert-XL software normalized the vertebral height based on the average height of the L2-L4 segment in order to minimize the influence of interindividual variation of body size. The average Z-scores for vertebral heights and ratios provided by the software were close to zero indicating that the normalization procedure appropriately corrected for smaller stature in Argentine women. Consequently, the reference values for morphometry X-ray absorptiometry (MXA) were appropriate for our population. In summary, we found that (1) in ``normal' women the anterior heights of the thoracic vertebrae (and therefore the A/P ratio) were higher in premenopausal than in postmenopausal women; and (2) the normalization approach corrected for differences of vertebral height and allowed utilization of the manufacturers software in our population. Received: 28 June 1999 / Accepted: 2 November 1999     

Effect of central precocious puberty and gonadotropin-releasing hormone analogue treatment on peak bone mass and final height in females

To evaluate the effect of central precocious puberty (CPP) and its treatment with gonadotropin-releasing hormone (GnRH) analogues on final height and peak bone mass (PBM), we measured lumbar bone mineral density (BMD) in 23 girls at final height. Patients were distributed in two groups. Group 1: 14 patients with progressive CPP were treated with GnRH analogues; seven patients received buserelin (1600 μg/daily), subsequently switched to depot triptorelin (60 μg/kg/26–28 days); seven patients were treated with depot triptorelin (60 μg/kg/26–28 days); mean age of treatment was 6.2 years (range 2.7–7.8 years); the treatment was discontinued at the mean age of 10.1 years (range 8.7–11.3 years); final height was reached at the mean age 13.4 years (range 12.0–14.9 years). Group 2: 9 patients (mean age 6.5 years, range 4.8–7.7 years) with a slowly progressing variant of CPP were followed without treatment; final height was reached at the mean␣age␣13.6 years (range 12.5–14.8 years). Lumbar BMD (L₂-L₄ by dual energy X-ray␣absorptiometry) was measured in all patients at final height. In group 1, final height␣(158.9 ± 5.4 cm) was significantly greater than the pre-treatment predicted height (153.5 ± 7.2 cm, P < 0.001), but significantly lower than mid-parental height (163.2 ± 6.2 cm, P < 0.005). Subdividing the girls of group 1 according to the bone age at discontinuation of therapy (i.e. ≤11.5 years, n = 5, or ≥12.0 years, n = 9), the former patients had a final height significantly higher than the latter (163.7 ± 3.9 cm vs 156.5 ± 4.6 cm, P < 0.02). In group 2, final height (161.8 ± 4.6 cm) was similar to the pre-treatment predicted height (163.1 ± 6.2 cm, P = NS) and was not significantly different from mid-parental height (161.0 ± 5.9 cm). BMD values (group 1: 1.11 ± 0.14 g/cm², group 2: 1.22 ± 0.08 g/cm²) were not significantly different from those of a control group (1.18 ± 0.10 g/cm²; n = 20, age 16.3–20.5 years) and the patients' mothers (group 1: 1.16 ± 0.07 g/cm², n = 11, age 32.9–45.1 years; group 2: 1.20 ± 0.08 g/cm², n = 7, age 33.5–46.5 years). In group 1, the girls who stopped therapy at a bone age ≤11.5 years had significantly higher BMD (1.22 ± 0.10 g/cm²) compared to those who discontinued therapy at a bone age ≥12.0 years (1.04 ± 0.12 g/cm², P < 0.05). Conclusion In girls with progressive CPP, long-term treatment with GnRH analogues improves final height. A subset of patients with CPP does not require treatment because good statural outcome (slowly progressing variant). In CPP, the abnormal onset of puberty and the long-term GnRH analogue treatment do not impair the achievement of PBM. In GnRH treated patients, the discontinuation of therapy at an appropriate bone age for pubertal onset may improve both final height and PBM. Received: 5 June 1997 / Accepted in revised form 21 November 1997     

Breast cancer in Australian women under the age of 40

Objectives: A case-control-family study of breast cancer in women under the age of 40 was carried out in Melbourne and Sydney, Australia, from 1992 to 1995 to determine the risk factors for these women. Subjects included 467 incident cases identified by state cancer registries and 408 population-based controls. Methods: All participants completed a structured risk-factor questionnaire and family pedigree during an in-person interview. Where possible, cancers in first- and second-degree relatives were verified. Results: Multiple logistic regression analysis showed that the strongest risk factor for breast cancer was a family history of the disease - having at least one affected first-degree relative trebled the risk (relative risk [RR] = 3.3, 95 percent confidence interval [CI] = 1.9-5.8). Risk increased with height by three percent (standard error [SE] of one percent) per cm, and after adjusting for height, there was evidence for a decreased risk in women weighing 73 kg or more. There was an increased risk of breast cancer after the first full-term birth (RR = 1.8, CI = 1.0-3.5) but this risk fell by 30 percent (SE = 11 percent) with each subsequent livebirth. Conclusions: The effects of other reproductive factors and oral contraceptive use, although not nominally significant, were in accord with published findings from similar studies in young women. This study of Australian women has indicated that some risk factors for breast cancer in women under age 40 differ from those reported for older women either in direction (e.g., weight) or relative importance (e.g., family history).     

Depression of long term potentiation in gerbil hippocampus following postischemic hypothermia

To investigate the mechanism of chronic cell death following postischemic hypothermia, the change of N-methyl- -aspartate receptor (NMDAR) were examined by immunohistochemistry of NMDAR1 and long-term potentiation (LTP) in the CA1 subfield of the gerbil hippocampus. At 1 week following postischemic hypothermia (32°C×4 h), all CA1 neurons survived; however, immunoreactivity of NMDAR1 increased in neuronal perikarya whereas decreased in dendrites in the CA1 neurons. The abnormality was still observed in remaining CA1 neurons at 1 month after hypothermia. LTP was also significantly depressed at 1 week after hypothermia. These results suggest that some abnormalities in the glutamate receptor may be caused by ischemia; such abnormality would persist in spite of hypothermia treatment, resulting in the depression of LTP.     

Modulation of dihydroxyphenylacetaldehyde extracellular levels in vivo in the rat striatum after different kinds of pharmacological treatment

We recently identified the direct product of dopamine (DA) by monoamine-oxidase (MAO) activity, dihydroxyphenylacetaldehyde (DOPALD) in the trans-striatal dialysate. Based on these findings, in this work, we directly measured the variations in DOPALD levels after various kinds of pharmacological treatment in rat striatal extracellular fluid. Using both reversible and irreversible MAO inhibitors, we found that MAO-A inhibition suppressed, whereas MAO-B inhibition did not modify DOPALD levels in the dialysate. The vesicular DA uptake blocker Ro 4-1284 led to an increase in extracellular DA and DOPALD, whereas the increase in extracellular DA obtained after administration of the plasma membrane DA uptake blocker GBR-12909 occurred without concomitant changes in DOPALD extracellular levels. Microinfusions of DA through the dialysis probe or systemic administration of L-DOPA increased striatal DOPALD to a greater extent compared with other DA metabolites, both in intact and in 6-hydroxydopamine (6-OHDA)-lesioned striatum. This study indicates that the direct product of MAO activity within the rat striatum derives from the activity of the isoenzyme MAO-A. The assay of DOPALD, together with DOPAC, represents a reliable tool to measure directly, in freely moving animals, DA oxidative metabolism. As recent studies have shown that microinfusions of exogenous DOPALD might induce cell death, pharmacological modulation of DOPALD levels might also be relevant for an understanding of the mechanisms involved in DA neurotoxicity.     

郑州市初中矮身材学生致矮因素分析

目的分析矮身材儿童的致矮因素,为开展针对性干预措施、降低矮身材发生率提供依据.方法对郑州市4所中学初中生3 240名进行身高测量,筛选出92例矮身材儿童为研究对象,将正常身高儿童1∶1与之配对,进行问卷调查、体格测量、骨龄判定、血清激素及头发微量元素测定.结果矮身材检出率为3.21%;病例与对照组间父母身高、骨龄差异有显著性(P<0.001),出生方式、出生体重差异有显著性(P值分别<0.05和0.01);矮身材儿童偏食者多、缺乏体育活动,两组差异有显著性(P值分别<0.05和0.01);矮身材组血清睾酮均值低于对照组(P<0.001),睾酮与身高、骨龄之间存在正相关性.结论矮身材发生与父母身材矮小、难产、低出生体重、偏食、体育活动少、血清睾酮水平偏低等因素有关;儿童少年矮身材多为体质性生长发育迟缓.