Enzyme activities associated with the demyelinating phase of canine distemper

Summary Canine distemper, a naturally occurring viral disease of dogs which often terminates in parainfectious demyelination, was used as a model to study the role of acid proteinase, neutral proteinase and beta-glucuronidase in demyelination. These enzymes were higher in cerebella of dogs with distemper-associated demyelination than in age-matched controls. The highest elevations corresponded with the most severely demyelinated cerebella. The source of the increased enzymes activities was apparently unrelated to the lymphocytes present in areas of demyelination.The direct effect of distemper virus and serum on these enzymes was tested in canine glial monolayers. Virus infection resulted in lower enzyme activities in cells concomitant with the appearance of cellular lesions. There was a relative increase of beta glucuronidase activity in the media suggesting that distemper virus released pre-formed lysosomal enzymes. Serum which was obtained from dogs with distemper-associated demyelination and had previously demyelinated cerebellar explants, also decreased activities of all 3 enzymesin vitro.The 3 enzymes were measured in gerbil brains at various time intervals following unilateral cerebral infarction to determine if processes other than demyelination also caused these enzymes to be increased. Uncomplicated ischemic necrosis (24 h post infarction) did not alter the activities of these enzymes. Invasion of macrophages to ingest and digest necrotic tissue 10 days after infarction resulted in greatly increased acid proteinase and beta-glucuronidase, but unchanged neutral proteinase, activities.It was concluded that the increased activities of acid proteinase and beta-glucuronidase in demyelinated tissue probably are derived from macrophages ingesting damaged tissue. Neutral proteinase may be more specifically involved in the demyelinating process since this is partially located within myelin and can degrade the basic protein of myelin.Supported in part by Research grant Nos. GM 1052 and Al-09022 from National Institutes of Health Service, U.S. Public Health Service.     

用非同位素原位杂交组化在光镜和电镜水平观察前阿黑皮素mRNA在垂体的分布

用地高辛标记反意前阿黑皮素(pro-opiomelanocortin,POMC)cRNA探针原位杂交组化在光镜和电镜水平观察了POMC mRNA在大鼠垂体的分布,并比较了碱性磷酸酶(AKP)显色系统和辣根过氧化酶(HRP)显色系统在光镜水平上的敏感性.结果:POMC mRNA广泛地分布于垂体的中间叶和前叶.中间叶全部细胞均为POMC mRNA阳性.前叶中除前叶的腹侧缘和前叶与中间叶交界处阳性细胞较少外,都有较多的POMC mRNA阳性细胞分布.AKP显色系统比HRP显色系统敏感.在电镜水平,POMC mRNA主要分布于粗面内质网,少数分泌颗粒可能呈阳性反应,胞核未见阳性反应沉淀.文内还就阳性分泌颗粒在调节细胞合成功能方面可能起的作用进行了讨论.     

The optical characteristics of aiming scopes in archery

Technical advancements in target archery have been extended to widespread use of "scopes" which magnify the target. In fact, these optical devices are simple converging lenses used at an arm's length from the eye. They produce a magnified image, but it is an image that suffers from significant dioptric blur, diminished somewhat by use of a peep sight in the bowstring which functions as an aperture stop. Visual acuities were taken with these scopes and, as might be expected, it was found that subjects saw no better with them. With the highest power scopes, acuity actually decreased. Experienced archers did slightly better with these aids than those with no archery experience.     

GNAS gene mutations affecting XLαs and bone health: A long neglected relationship

The GNAS locus is an imprinted site. The α-subunit of the stimulatory G protein (Gsα) and extralarge variant (XLαs) are the two important products of the GNAS locus. The abnormal expression of Gsα is associated with pseudohypoparathyroidism (PHP) and related disorders, including Albright hereditary osteodystrophy (AHO), pseudopseudohypoparathyroidism (PPHP), and progressive osseous heteroplasia (POH). XLαs protein can mimic the catalytic intracellular synthesis of cyclic adenosine monophosphate (cAMP) by Gsα in response to parathyroid hormone (PTH) stimulation, which may be involved in the pathogenesis of PPHP and POH in patients with paternal GNAS defects. A paternally inherited nonsense variant in the first exon of XLαs in an adult patient may be associated with fractures and osteopetrosis. The relationship between the XLαs product of the GNAS locus and bone remodeling may have been overlooked. Here, we summarize the phenotypes of genetic mouse models and clinical cases of XLαs variations and suggest that the abnormal paternal expression of XLαs may be associated with the development of POH and affect osteoblast and osteoclast differentiation.     

重度蒸汽吸入性损伤犬伤后肿瘤坏死因子水平的改变及其意义

目的研究蒸汽吸人性损伤犬伤后血浆肿瘤坏死因子水平的改变及其与吸入性损伤呼吸循环功能受损程度的关系.方法取犬15条,以蒸汽致重度吸入性损伤,分别于伤前、伤后1h、2h、3h、4h观察有呼气相气道阻力(RE)、心率(HR)、心输出量(CO)、动脉血氧分压(PaO2)、血浆TNF水平;伤后4h致死动物,取肺做病理检查.结果伤后1hTNF、RE升高,HR、CO、PaO2下降;TNF与RE正相关(r=O.965,P<O.01),与CO负相关(r=-0.824,P<O.05).结论严重蒸汽吸入性损伤激发TNF分泌,这是诱发肺损伤及循环系统甚至全身器官功能障碍的重要原因.     

Considerations for inter-hospital extracorporeal cardiopulmonary support resuscitation and transport

The availability of commercial, pre-packaged extracorporeal cardiopulmonary support (ECPS) circuits, which are simplified for rapid set-up and priming, has made the intra-hospital resuscitation of moribund patients routine. The successful utilization of this technology in the emergent setting requires planning and the coordination of personnel familiar with the technology. Many issues must be addressed when a patient requiring life-sustaining support utilizing this technology at an outlying hospital, must be transported while on ECPS. After reducing the size and weight of the ECPS cart and obtaining Federal Aviation Administration approval for use during aeromedical transport, the Emanuel Hospital Mobile Surgical Transport Team (MSTT) was able to extend the use of emergency cardiopulmonary bypass to outlying medical facilities. The patients selected for transport, using ECPS, are a group of patients with a potentially survivable pathology unlikely to survive inter-hospital transport without such measures. This report describes our experience with inter-hospital transport of patients on ECPS with special emphasis on transport considerations.     

Association of heterotopic neuroglial tissue with an arachnoid cyst in the internal auditory canal

An arachnoid cyst arising within the internal auditory canal, or within the cerebellopontine angle and subsequently extending into the internal meatus and enlarging it, is a rare occurrence. Nevertheless, the neurootologist and the neurosurgeon have an interest in its existence because its clinical manifestations are identical with the ones produced by a schwannoma, involving overwhelmingly the cochleovestibular nerve in that region. An equally rare observation in that location is the presence of ectopic neuroglial tissue. The two can occur independently or in combination. Examples of such lesions are presented, and their possible pathogenesis is discussed.