Comparison between radial bone mineral density measured by single photon absorptiometry and histomorphometric bone mass parameters measured on iliac crest biopsies

Summary Bone mineral density (BMD) measured by single photon absorptiometry (SPA) with a Moolsgard 1100^® device on the distal and proximal part of the radius was compared with histomorphometric parameters measured on iliac crest biopsies in 37 patients suffering from various bone disorders. In the whole population, a good correlation was observed between the cancellous bone volume (Cn-BV/TV) measured on iliac crest biopsies and BMD from both the proximal part of the radius (r=0.76, p < 0.001) and the distal part of the radius (r=0.73, p < 0.001). Significant, although weaker correlations, were also found between the cortical width and the BMD from the distal part (r=0.37, p < 0.001) and the proximal part (r=0.44, p < 0.001) of the radius. In the 14 untreated osteoporotic patients, only a significant Spearman correlation was observed between the iliac Cn-BV/TV and the proximal radial BMD (r=0.69, p < 0.05). It is thus not clear, whether radial proximal BMD correctly indicates cortical bone density in osteoporotic patients or not. The large internal variability of each of the two investigated methods and the small group of osteoporotic patients might explain the lack of correlation between the two methods in this group.     

Accumulation and effects of lead and cadmium on wood ducks near a mining and smelting complex in Idaho

A study of wood ducks (Aix sponsa) was conducted along the Coeur d'Alene River system in northern Idaho in 1986 and 1987. Most of this area has been subjected to severe contamination from lead and other metals from mining and smelting since the 1880s. In 1986, a preliminary study of wood duck nesting was conducted in the contaminated area; incubating hens captured in nest boxes were bled and weighed. Blood samples were used to determine lead and cadmium concentrations and physiological characteristics. In 1987, an intensive study of wood ducks involved trapping and monitoring nest boxes in the contaminated area. Blood and tissue samples were also taken from wood ducks from a reference area without known contamination from metals. Lead levels in blood and tissues of most wood ducks from the contaminated area frequently exceeded those considered hazardous to birds; maximum levels (wet weight) of lead were 8 g g^–1 in blood and 14 g g^–1 in liver. Changes in physiological characteristics constituted the only evidence of potentially adverse effects from lead. In the contaminated area, nesting success (55% unadjusted, 35% Mayfield estimate) was less than in other areas where predation was low and nest boxes were used; but lead concentrations and physiological characteristics of blood were similar in successful and unsuccessful hens.Values of ALAD, hemoglobin, and body mass were negatively correlated with blood concentrations of lead, whereas protoporphyrin was positively correlated with lead levels in the blood. Some of the protoporphyrin values (1,091 g dl^–1 in a male and 756 g dl^–1 in a female) equalled those associated with lead toxicosis in experimental birds. ALAD activity was low in most birds from the contaminated area; values of 0 were obtained from 11 birds. Lead levels in blood, ALAD, protoporphyrin, and hemoglobin were significantly different between birds from the contaminated and reference areas. Concentrations of lead in ingesta of wood ducks ranged from 0.9 to 610 g g^–1 in the contaminated area and 0.2 to 0.6 g g^–1 in the reference area. Levels of cadmium in kidneys of wood ducks ranged from 1g g^–1 to 20 g g^–1 in the contaminated area and from only to 0.1 g g^–1 to 1 g g^–1 in the reference area. Cadmium concentrations were less than known effect levels.     

Regional alterations of brain biogenic amines and GABA/glutamate levels in rats following chronic lead exposure during neonatal development

Wistar rat pups were administered either a high dose of lead acetate (400 g lead/g body weight/day) or a low dose (100 g lead/g body weight/day) by gastric intubation, from 2 days through 60 days of age. The rats on both these doses exhibited statistically significant decreases in body and brain weights throughout the lead treatment period. A group of rats on high dose was also rehabilitated by discontinuing the lead from 60 days of age. In these rats, at 160 days of age, the body weight but not the brain weight recovered to normal levels. During the lead intake, the rats on high dose revealed significant elevations in the levels of noradrenaline (NA) in the hippocampus (HI), cerebellum (CE), hypothalamus (HY), brainstem (BS), and accumbens-striatum (SA). The elevated levels in all the above regions except in the HY persisted even after rehabilitation. The dopamine (DA) levels changed significantly in opposite directions in HY (elevation) and BS (reduction) during the lead treatment, and the HY recovered after rehabilitation. Under lead, the serotonin (5HT) levels were elevated significantly in the HI, BS and MC (motor cortex), while after rehabilitation the abnormality persisted only in the MC. Low dose lead treatment was also effective on the same areas of brain. In the low dose group, estimation of the levels of GABA and glutamate were also done, and a significant decrease of GABA in CE and glutamate in MC was observed. The differences observed in the neurotoxic effects (none or significant) of lead in the different regions for each of the transmitters (NA, DA, 5HT) supports the interesting conclusion that the vulnerability of the axon terminals of any given type is dependent on some regional factors, although the projections of the different regions originate from an apparently similar category of neurons in the brain stem.     

单链构象多态性分析技术检测结核杆菌利福平耐药基因

目的：研究本地区临床分离结核杆菌ｒｐｏＢ基因突变与利福平（ＲＦＰ）耐药性的关系。方法：对３６株ＲＦＰ敏感株和４４株ＲＦＰ耐药株ｒｐｏＢ基因的３２８ｂｐ的ＰＣＲ扩增产物进行单链构象多态性（Ｓｉｎｇｌｅ－ｓｔｒａｎｄ ｃｏｍｆｏｒｍａｔｉｏｎｐｏｌｙｍｏｒｐｈｉｓｍ,ＳＳＣＰ）分析。结果：３６株ＲＦＰ敏感株的ＳＳＣＰ带谱均与参考株Ｈ３７Ｒｖ相同,４４株ＲＦＰ耐药株中,２５株高度ＲＦＰ耐药株和１１株低度ＲＦＰ耐药株的ＳＳＣＰ带谱与Ｈ３７Ｒｖ带谱有差异;另８株低度ＲＦＰ耐药株的ＳＳＣＰ带谱与Ｈ３７Ｒｖ带谱相同。结论：ＳＳＣＰ分析可检测出ｒｐｏＢ基因突变,该基因突变与本地区临床分离结核杆菌对ＲＦＰ耐药有关。     

Children's Health and the Environment—The First Herbert L. Needleman Award Lecture

Children today are exposed extensively to toxins in the environment. Prominent among these are exposures to over 70,000 synthetic chemicals, all newly developed in the past 50 years and largely untested for their hazards to children's health. Children are uniquely vulnerable to toxins, and with increasing incidence they are developing chronic, disabling, life-threatening diseases known or suspected to be of environmental origin–asthma, endocrine disruption, cancer, and the diseases caused by tobacco. Pediatricians need to consider toxic etiologies in the differential diagnosis of childhood illness.     

In vivo labeling of sigma receptors in mouse brain with [3H]4-phenyl-1-(4-phenylbutyl)piperidine

4-Phenyl-1-(4-phenylbutyl)piperidine(4-PPBP) is a very potent ligand for σ (Sigma) receptors. The present study was undertaken to evaluate [³H]4-PPBPas a radioligand for in vivo labeling of cerebral σ receptors. After intravenous administration of [³H]4-PPBP to mice, there is high uptake of radioactivity in the brain. The regional distribution of radioactivity in the brain 2 h after intravenous injection of [³H]4-PPBP parallels the in vitro binding of the radioligand in rat brain (pons/medulla > cerebellum ≥ prefrontal cortex ≥ parietal cortex > hypothalamus > olfactory tubercle ≥ thalamus > hippocampus > striatum). Pretreatment with haloperidol (2 mg/kg) significantly decreases the radioactivity measured in the brain 30–120 min after injection of [³H]4-PPBP. Pretreatment with unlabeled 4-PPBP or ifenprodil also significantly decreases radioactivity in the brain 2 h after injection of [³H]4-PPBP, in a dosedependent manner. The in vivo binding of [³H]4-PPBP in the brain also is significantly inhibited by SL 82.0715, BMY 14802, 1,3-di-o-tolylguanidine (DTG), and (+)-enantiomers of pentazocine, SKF 10,047, and 3-PPP, but not by the corresponding (?)-enantiomers, consistent with stereoselectivity of inhibition obtained in in vitro binding studies. In contrast, pretreatment with dizocilpine and spiperone does not inhibit in vivo binding of [³H]4-PPBP. The results indicate that [³H]4-PPBP would be a suitable radioligand for in vivo labeling of σ receptors in brain. © 1995 Wiley-Liss, Inc.

1 This article is a US Government work and, as such, is in the public domain in the United States of America

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ROC曲线在评价铅中毒指标中的应用

目的评价几种铅中毒指标筛选不同水平职业性铅接触的准确性。方法连续性收集１５７名铅接触工人的血标本,同时测定血铅、红细胞游离原卟啉（ＦＥＰ）、锌原卟啉（ＺＰＰ）、尿铅、尿δ氨基酮戊酸（δＡＬＡ）,以血铅≥４０、≥６０μｇ／ｄｌ的铅接触水平为金标准,用ＲｅｃｅｉｖｅｒＯｐｅｒａｔｉｎｇＣｈａｒａｃｔｅｒｉｓｔｉｃ（ＲＯＣ受试者工作特征）曲线分析软件评价所测定指标筛选血铅≥４０、≥６０μｇ／ｄｌ职业性铅接触的价值,在ＲＯＣ曲线上制定各测定指标筛选上述２个铅接触水平的最佳临界点,用ＥＰＩＮＦＯＲ统计软件比较筛选血铅≥４０、≥６０μｇ／ｄｌ的平行试验的敏感度。结果筛选血铅≥４０、≥６０μｇ／ｄｌ的铅接触水平,ＲＯＣ曲线下的面积（ＡＵＣＲＯＣ）最大的是ＺＰＰ,其他依次为ＦＥＰ、尿铅、尿δＡＬＡ;联合ＺＰＰ与ＦＥＰ的平行试验的敏感度高于联合尿铅与尿δＡＬＡ的平行试验。结论筛选血铅≥４０、≥６０μｇ／ｄｌ水平的职业性铅接触,ＺＰＰ的准确性最高,并且联合ＺＰＰ与ＦＥＰ的平行试验的敏感度高于联合尿铅与尿δＡＬＡ的平行试验。     

右前外侧切口不阻断主动脉体外循环心脏直视手术57例

本研究采用右前外侧切口不阻断主动脉体外循环的方法对５７例心脏病人施行了心内直视手术。结果表明,一例房缺病人因引流多而再次开胸止血,另一例法乐氏四联症术后残余分流者术中修补不满意,其余效果良好,无手术死亡及术后住院死亡,无伤口感染发生;也解决了长期以来许多女性病人因正中切口显眼的瘢痕所造成的心理压力,取得良好的手术美容效果。     

儿童接触低水平铅与智能发育的关系研究

为探讨接触低水平铅是否对儿童智能发育产生影响,根据血铅值将儿童分为低血铅组（血铅＜１０μｇ／ｄｌ）和高血铅组（血铅≥１０μｇ／ｄｌ）,比较两组之间婴幼儿智能发育和学龄前儿童智力测验结果是否有差异。结果高血铅组儿童的ＰＤＩ、ＶＩＱ、ＰＩＱ和ＦＩＱ高于低血铅组。单因素分析提示血铅与ＣＤＣＣ量表中的心理运动发育指数（ＰＤＩ）以及ＷＰＰＳＩ量表中的语言智商（ＶＩＱ）、操作智商（ＰＩＱ）和总智商（ＦＩＱ）存在负相关关系,ｒ分别为－０．１４５８,－０．３３３０,－０．２３１６,－０．３１３３;高血铅组高于低血铅组。但多元回归分析显示血铅值与智能发育无相关关系,表明铅可能是阻碍儿童智能发育的一个危险因素。但当血铅水平不太高时（血铅值不高于２５μｇ／ｄｌ）的相关关系不明显。     

Improvement of brain single photon emission tomography (SPET) using transmission data acquisition in a four-head SPET scanner

Attenuation coefficient maps (-maps) are a useful way to compensate for non-uniform attenuation when performing single photon emission tomography (SPET). A new method was developed to record single photon transmission data and a-map for the brain was produced using a four-head SPET scanner. Transmission data were acquired by a gamma camera opposite to a flood radioactive source attached to one of four gamma cameras in the four-head SPET scanner. Attenuation correction was performed using the iterative expectation maximization algorithm and the-map. Phantom studies demonstrated that this method could reconstruct the distribution of radioactivity more accurately than conventional methods, even for a severely non-uniform-map, and could improve the quality of SPET images. Clinical application to technetium-99m hexamethylpropylene amine oxime (HMPAO) brain SPET also demonstrated the usefulness of this method. Thus, this method appears to be promising for improvement in the image quality and quantitative accuracy of brain SPET.This work was presented in part at the World Congress on Medical Physics and Biomedical Engineering, 7–12 July 1991, Kyoto, Japan