电离辐射对放射工作者职业健康的影响

目的 分析放射工作者外周血象、淋巴细胞微核及染色体畸变情况,为放射工作者职业防护和健康监测提供依据。方法 对2015年、2017年和2019年连续3次接受健康检查的127名放射工作者进行淋巴细胞微核、染色体及血象分析,将其设为放射组。另外选取133名无射线接触史的医务人员设为对照组;结果 放射组中淋巴细胞微核率和染色体畸变率高于对照组,白细胞和血小板计数低于对照组,均具有统计学意义（P < 0.05）。127名放射工作者外周血白细胞总数随着接触电离辐射时间的增长逐渐降低,染色体畸变率逐渐增加,均具有统计学意义（P < 0.05）。损害工龄大于20年的放射工作者染色体畸变率高于低工龄组,不同损害工龄之间比较无统计学意义（P > 0.05）。核医学与介入治疗工种染色体畸变率高于其他工种,具有统计学意义（P < 0.05）。结论 长时间接触低剂量电离辐射可使放射工作者白细胞总数降低和淋巴细胞染色体畸变率增加,应加强放射工作者防护措施以备降低电离辐射损伤程度,特别要加强核医学和介入治疗放射工作人员的职业防护。     

Magnetic and electrical stimulation of undulating nerve fibres: a simulation study

Mathematical models of myelinated nerve fibres are highly stylized abstractions of real nerve fibres. For example, nerve fibres are usually assumed to be perfectly straight. Such idealizations can cause discrepancies between theoretical predictions and experimental results. One well-known discrepancy is that the currently used models predict (contradictory to experimental findings) that an activation of nerve fibres is not possible with a pure transverse electric field. This situation occurs when a magnetic coil is placed symmetrically above a straight nerve fibre for magnetic nerve stimulation, or when an anode and a cathode are placed equidistantly on a line perpendicular to the fibre in the case of electrical stimulation. It is shown that this discrepancy does not occur if the physiological undulation of peripheral nerve fibres is included in the models. Even for small undulation amplitudes (e.g. 0.02 mm), it is possible to activate the fibre in these positions. For physiological undulations, as found in the literature, and favourable (off-centre) positions, the typical reduction of the thresholds is in a range between one and five, compared with perfectly straight fibres.     

Lymphocyte concanavalin A capping in hereditary cerebral haemorrhage with amyloidosis — Dutch type

Summary Lymphocyte capping with concanavalin A was studied in 11 patients with hereditary cerebral haemorrhage with amyloidosis (Dutch type) and 10 controls. No difference in capping was found between patients and controls. Abnormal lymphocyte concanavalin A capping has been reported in patients with the Icelandic type of cerebral amyloidosis and in patients with Alzheimer's disease, a disease in which cerebral amyloid angiopathy can also be found. The results suggest a difference in pathogenesis between the Dutch type of cerebral amyloidosis and the other amyloid diseases.Members of the Amyloid Research Group, Leiden     

The dynamics of β1 integrin expression during peripheral nerve regeneration

The aim of the present study was to examine the expression of 1 integrin subunit after peripheral nerve transection. After sciatic nerve transection two experimental procedures were used; changes in the freely regenerating rat sciatic nerve were compared to a situation in which spontaneous regeneration was prevented by suturing both ends of the nerve to the muscle next to the point of transection. Specimens for morphological analysis were collected 6 h, 1, 3, 5, 7 days and 2, 4, 6 and 8 weeks after the axotomy. Sections from the proximal (two zones) and distal (three zones) stumps next to the point of transection were stained with antibodies against 1 integrin subunit, macrophages, collagen types I and III, and S-100 protein. The control nerves showed 1 integrin-stained cells in the perineurium and vasa nervorum but the endoncurium was negative. Positively stained endoneurial fibroblast-like cells could be seen in the proximal part of the nerve already at 24 h after transection. The number of these positively stained cells increased steadily; they were most numerous 4 weeks after transection in the distal zone 2. Subsequently, the number of positively stained endoneural cells declined sharply and 8 weeks after transection no positively stained cells could be found. The morphological appearance and the immunohistochemical properties of the cells suggest that the majority of 1 integrin-positive cells are endoneurial fibroblast-like cells. Thus, the process appeared to be dynamic, starting from the proximal part and continuing to the distal parts, and was similar in both experimental groups. The positive staining in perineurial cells indicate that 1 integrin, which is an important mediator of the cell-matrix interaction, may have an essential role in the formation and strengthening of the normal peripheral nerve structures. Furthermore, 1 integrin seems to have an active role in reactions which occur during the early phases of peripheral nerve regeneration.     

雷公藤多甙对肾性蛋白尿患者外周血单个核细胞作用的研究

通过琼脂糖凝胶电泳, Ｈ Ｅ 染色和流式细胞仪检测用雷公藤多甙治疗肾性蛋白尿患者 ２ 周后外周血单个核细胞的凋亡情况。经治疗后患者外周血单个核细胞在形态上出现典型的细胞核固缩、碎裂,琼脂糖凝胶电泳显现特征性的“梯状”带,流式细胞仪上出现亚二倍体峰。提示雷公藤多甙能诱导肾性蛋白尿患者外周血单个核细胞的凋亡。     

遗传性压迫易感性神经病(4例临床与病理)

目的从临床、电生理及病理方面对遗传性压迫易感性神经病（ＨＮＰＰ）进行探讨,以提高对本病的认识。方法４例经临床及腓肠神经活检确诊,肌电图检测临床受累或未受累的肢体的感觉或运动传导速度;腓肠神经活检标本分别做ＨＥ、Ｍａｓｏｎ染色和Ｆｌｅｍｍｉｎｇ染色光镜观察。结果肌电图为广泛神经传导异常,甚至出现在临床未受累的神经支配区;腓神经活检显示部分神经纤维明显增粗,轴索正常。结论ＨＮＰＰ与遗传关系密切,但也有散发,电生理检查是重要的筛选手段,神经活检见到髓鞘增粗或典型的腊肠样结构是重要的确诊手段     

Fetal Krabbe leukodystrophy

Summary Two new cases of Krabbe disease were diagnosed prenatally in a family with two previous affected children. The activity of galactosylceramide--galactosidase was virtually absent in cultured amniotic cells.The prenatal diagnosis was confirmed enzymatically in cultured fibroblasts, brain, and visceral organs.Light and electron microscopy studies in both fetuses, 20 and 23 weeks of gestational age respectively, revealed the presence of typical globoid cells in the white matter of the spinal cord. Specific inclusions were also found in the brain stem and in peripheral nerves of the second fetus.A comparison with other Krabbe disease fetuses described in the literature contributes to the consensus that abnormal morphological findings can be expected in particular in the most actively myelinating areas of the nervous system.Although most of the cells containing the specific melusions are probably non-glial in nature, some of them could represent myelination glia.This work was supported by the FGWO (grants nos. 3.0033.77 and 3.0012.77), by the FRSM (grant no. 3.4542.79), and by the Baron Charles Bracht Foundation     

Antibodies in sera from patients with inflammatory demyelinating polyradiculoneuropathy react with ganglioside LM1 and sulphatide of peripheral nerve myelin

Summary Sera from 23 patients with acute Guillain Barré syndrome (GBS), 15 patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and from 40 age-matched blood donors were analysed for antibodies to acidic glycosphingolipids from human brain and peripheral nerve. Antibodies to ganglioside LM1, the major ganglioside of peripheral nerve myelin, were found in 43% of GBS and in 67% of CIDP patients' sera, and in 20% of the blood donors. However, anti-sulphatide antibodies were detected in 65% and 87% of the sera from GBS and CIDP patients, respectively, but only in 15% of the control sera. Sulphatide is the major acidic glycosphingolipid in myelin and its concentration in peripheral nerve myelin is 100 times higher than that of LM1. The high frequency of LM1 and, in particular of sulphatide antibodies, might thus be relevant to the pathogenesis of the GBS and CIDP. Abbreviations: The ganglioside nomenclature used according to Svennerholm [24]. LM1, IV³NeuAc-nLcOse₄Cer, GM1, II³NeuAcGgOse₄Cer; GD1a, IV³NeAc,II³NeuAc-GgOse₄Cer; GD1b, II³(NeuAc)₂-GgOse₄Cer; GT1b, IV³NeuAc,II³(NeuAc)₂-GgOs₄Cer; LU1, sulphate-3-glucuronyl paragloboside; sulphatide, 3-sulphogalacto-sylceramide     

Dynamic aspects of peripheral nerve changes in progressive neural muscular atrophy

Summary Serial nerve biopsies were performed at an early, and at an advanced stage of the disease in 2 patients with progressive neural muscular atrophy. The early biopsy showed a complete loss of the large diameter and thickly myelinated fibres, as well as an expansion of the endoneurial interstitium in both cases. Myelinated and unmyelinated fibres exhibited axonal degeneration in all biopsies occasionally. Onion bulb formation, a typical feature of peripheral neuropathy in neural muscular atrophy, was found to be prominent only in the latter biopsies. As regards the formal pathogenesis of hypertrophic neuropathy in neural muscular atrophy, axonal dystrophy and interstitial changes of the endoneurium were regarded as primary phenomena, demyelination and onion bulb formation as secondary. A possible causal relation between axonal dystrophy and interstitial changes, observed in these cases, is discussed in the light of the present literature.

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Zusammenfassung Bei 2 Patienten mit progressiver neuraler Muskelatrophie wurden Nervenbiopsien jeweils in einem frühen und in einem fortgeschrittenerem Stadium der Erkrankung entnommen und verglichen. In beiden Fällen zeigten bereits die frühen Biopsien ein völliges Fehlen der großkalibrigen, dickbemarkten Axone. Ebenfalls als frühe Veränderung wurde eine Erweiterung des endoneuralen Interstitiums festgestellt. Eine geringe Anzahl der vorhandenen bemarkten und unbemarkten Axone in allen Biopsien wies degenerative Veränderungen auf. Die für die progressive neurale Muskelatrophie typische Zwiebelschalenbildung der Schwannschen Zellen — möglicherweise eine Reaktion auf wiederholte De-und Remyelinisierungsvorgänge um dystrophische Axone — trat erst in den späteren Biopsien deutlicher hervor. Hinsichtlich der formalen Genese der hypertrophischen Neuropathie bei neuraler Muskelatrophie sind nach diesen Beobachtungen axonale Dystrophie und interstitielle Veränderungen des Endoneuriums als primäre Entmarkung und Zwiebelschalenbildung als sekundäre Phänomene zu betrachten. Die Möglichkeit einer kausalen Beziehung zwischen axonaler Dystrophie und interstitiellen Veränderungen wird an Hand der vorliegenden Befunde und Literatur diskutiert.

     

The pineal gland is not essential for circadian expression of rat period homologue (rper2) mRNA in the suprachiasmatic nucleus and peripheral tissues

To investigate the functional involvement of the pineal gland in circadian expression of the rat period homolog gene (rPer2) in the suprachiasmatic nucleus (SCN) and peripheral tissues, we performed Northern blot analysis in tissues from pinealectomized rats. The ectomy did not have any significant effects on rPer2 mRNA expression patterns both in a daily light-dark condition and in a constant darkness. These results suggest that the rhythmic secretion of pineal melatonin is not essential for the circadian expression of clock genes in the SCN and other peripheral tissues of rats.