Human immunodeficiency virus (HIV)-related chronic relapsing inflammatory demyelinating polyneuropathy with multifocal unusual onion bulbs in sural nerve biopsy

Summary This is obviously the first report on a case with a spontaneous sensu strictu relapsing variant of human immunodeficiency virus (HIV)-related polyneuropathy. Its manifestation preceded LAS. Intrathecal HIV-antibodies developed between the most severe third and fourth episode. Analysis of sural nerve biopsy was consistent with a multifocally accentuated chronic inflammatory demyelination, characterized by unusual onion bulb-like Schwann cell formations with irregular voluminous layers, electron density, aggregation of filaments, multiple indented nuclei, and numerous enclosed collagen pockets. A direct or immune-mediated indirect specific influence on Schwann cell morphology by HIV might be discussed. Virus-like particles and ultrastructural markers of HIV were not detectable.     

An ultrastructural study on anterior cruciate ligament reconstruction using autogenous patellar tendon grafts in dogs

An ultrastructural study was undertaken concerning morphological changes within the autografted patellar tendon (PT) after being transplanted to the anterior cruciate ligament (ACL) in mongrel dogs. After 4 weeks, the arrangements of both large and small collagen fibrils in the PT graft became disordered, and the number of inflammatory cells increased. However, the same PT grafts revealed postsurgical signs of newly-produced collagen fibrils around activated fibroblasts at 12 to 24 weeks. At 52 weeks after the transplantation, small collagen fibrils increased in both number and density, showing a remarkable morphological similarity to the collagen fibrils of normal ACL. These data indicate that the characteristics of the PT graft eventually resemble those of a normal ACL. This paper was presented in part at the Combined Meeting of the Orthopedic Research Societies of the USA, Japan and Canada in Banff, Alberta, Canada, October, 1991.     

枸杞多糖对高温损伤小鼠睾丸曲细精管影响的电镜观察

为研究枸杞多糖对小鼠睾丸生细红胞的作用，本次以热吹风器对小鼠双侧睾丸透热(B组)，另取正常不透热小鼠为空白对照（A组)，蒸馏水灌胃对照(C组)和透热后灌鼠枸杞多糖(D组)，进行实验观察，待B、C、D各组于透热结束后即刻、3天、1周、2周，5周处死动物，取双侧睾丸，常规作光镜和电镜观察。实验结果表明，B组各期生精细胞进行性受损，属肿胀溶解性细胞变性坏死过程，D组则在1周时受损部位和程度未见进行性加重，5周对基本恢复正常，提示枸杞多糖有明显的抗高温，保护生精细胞作用。     

Experimental model of chronic tonsillar herniation associated with early stage syringomyelia

This report describes an experimental model of chronic tonsillar herniation and its effects on the spinal cord. In ten rats, a small piece of chemically induced mammary cancer was transplanted to the supraoccipital bone. In all cases, the transplanted cancers grew into the posterior fossa, destroying the supraoccipital bone and compressing the cerebellum extradurally. In six of the ten rats, tonsillar herniation was observed at 8–14 weeks after transplantation. Transdural infiltration of the tumor cells was not apparent in any animal. In those rats with tonsillar herniation (n=6), the spinal cord from the C5 to the T8 segments showed enlargement of the central canal without exception. Histological examination revealed the following changes: stretching and thinning of the ependymal cells; swelling of the astrocytic processes; and extracellular edema, predominantly in the dorsal gray matter, but also in the ventral inner portion of the dorsal column. In the control group (n=4) and those rats without tonsillar herniation (n=4), such histological changes of the spinal cord were not observed. Although the lesions can not be regarded as representing mature syringomyelia, they most likely constitute an earlier evolutionary stage.     

Granular cell abrikossoff tumours of the larynx and tongue treated with the carbon dioxide (CO2) laser

Seven cases of granular cell Abrikossoff tumours of the larynx and tongue are reported: four in the tongue and three in the larynx. All of these tumours were removed with the carbon dioxide (CO₂) laser. The anatomical site of the origin and clinical features of granular cell tumours (GCT) are not specific. Histological, light microscopic, electron microscopic (EM) and immunohistochemical studies are required for diagnosis. The histogenesis and cellular derivation of GCTs is still controversial. The biological potential and lack of cellular atypia define a benign process. However, it is important to take into account that these tumours have ill-defined borders without a capsule. Radiation therapy has proved ineffective in the past. Surgical excision with a wide margin is required. Because of numerous advantages, for example, no bleeding, no oedema, minimal pain and quick recovery, CO₂ laser removal is the treatment of choice. The authors have not seen any recurrence or complications.     

Cell surface and nuclear changes during TNF-α-induced apoptosis in WEHI 164 murine fibrosarcoma cells

 Tumour necrosis factor (TNF)-α-induced apoptosis is associated with several nuclear and cell surface alterations, in particular with the condensation of chromatin and the fragmentation of the cell nucleus, formation of blebs on the cell surface and breakdown of the plasma membrane. However, there is little information about the relationship between the cell surface alterations and the nuclear changes during apoptosis. To study this, cultured WEHI cells were exposed to TNF-α over different time periods. The cytological changes were studied using a correlative approach, which allowed observation of the same cell consecutively under light, scanning and transmission electron microscopy. The earliest sign of cell alteration was a reduction of the number of microvilli after 15 min of TNF-α exposure. This reaction was reversible (reappearance of microvilli) and took place during the first hour, in which neither nuclear alterations nor plasma membrane breakdown were observed. The changes in the nucleus began with condensation of chromatin after approximately 1 h of TNF-α-exposure. After 4–5 h the microvilli disappeared again, particularly in areas where the formation of blebs (blebbing) was observed. Strikingly, cell surface alterations (bleb formation) were detected only in those cells that presented with condensed chromatin, and not in cells with a normal chromatin pattern, proving at least a close correlation between nuclear and cell surface changes during the process of apoptosis. Received: 7 October 1997 / Accepted: 23 March 1998     

Giant collagen plaques in Creutzfeld-Jakob disease

Summary We report two cases of Creutzfeld-Jakob disease with clusters of giant collagen fibers. To our knowledge, these abnormally large collagen fibers have never been described in patients with degenerative diseases of the central nervous system. The significance of the formation of such plaque-like large collagen fibers has as yet not been elucidated. It is felt that these represent a product of the degenerative process.Presented in part at the 68th Annual Meeting of the American Association of Neuropathologists, St. Louis, Missouri, June 18–21, 1992     

Adult-onset rod disease with abundant intranuclear rods

Summary The third case of adult-onset rod disease (nemaline myopathy) with abundant myofibrillar as well as intranuclear rods is described. The 61-year-old woman suffered from progressive weakness of proximal extremities and of the neck, mimicking polymyositis. Muscle biopsy revealed a striking myopathic pattern, with intranuclear rods occurring in 31% of the fibres. On light and electron microscopy and by immunohistochemical study, the rods differed from myofibrillar rods. The absence of -actinin in intranuclear rods suggests an enhanced readiness of actin filaments to bind to diverse proteins, instead of overproduction of -actinin as the pathogenetic basis of the rod formation.     

The distribution of lead in human hemopoietic tissue and spongy bone after lead poisoning and Ca-EDTA chelation therapy

Two iliac crest needle biopsies were taken from a 43-year-old lead-poisoned woman during and after completion of a Ca-EDTA treatment. By atomic absorption spectroscopy the first and second biopsy were found to contain 56, respectively 41.6 g lead/g wet tissue. In both biopsies 36% of the lead was extractable in 0.1 N HCl. Electron microbeam X-ray analysis proved to have too low sensitivity for quantitation of the lead in these biopsies. Laser microbeam mass analysis (LAMMA), performed only on the second biopsy, revealed a high and fairly constant residual lead concentration in all bone marrow cell nuclei (approximately 55 g/g) and a low lead concentration in the cytoplasm of the same cells (4–12 (g/g). The extracellular bone matrix lead was greatly concentrated in the superficial 3–6 m osteoid zone of the bony trabeculae and totally absent from deeper parts of the mineralized matrix. The LAMMA results are in good agreement with those of subcellular fractionation experiments and atomic absorption spectroscopy, provided that the relative volume fraction of nucleus and cytoplasm is accounted for. The high residual osteoid lead after completed chelation therapy indicates that lead has a stronger affinity for the organic than the mineral components of bone matrix.