Lateral Mobility of the Cell Adhesion Molecule L1 Within the Surface Membrane of Morphologically Undifferentiated and Differentiated Neuroblastoma Cells

Lateral mobility and localization in the surface membrane of the adhesion molecule L1 was studied in morphologically undifferentiated and differentiated neuroblastoma cells to gain insight into its possible association with the different molecular forms of N-CAM. In undifferentiated cells, the fraction of mobile L1 molecules is high and similar to that of N-CAM 140. Upon long-term morphological differentiation, the fraction of mobile L1 molecules is reduced by a factor of three and is similar to that of N-CAM 180, the predominant molecular form of N-CAM in differentiated neuroblastoma cells. Comparable to N-CAM 180, L1 is also preferentially accumulated at contact sites between these cells as seen by indirect immunofluorescence. These observations raise the question of whether at least part of the L1 molecules may be directly or indirectly (e.g. via N-CAM 180) linked to the cytoskeleton, thus stabilizing cell contacts between differentiated cells.     

Cerebrospinal fluid as a tool in the diagnosis of neurometabolic diseases: amino acid analysis before and after acid hydrolysis

We perform systematically amino acid analysis of the CSF before and after strong acid hydrolysis in children with unexplained neurological disease. By comparing the amino acid pattern before and after hydrolysis, defects can be traced in the metabolism not only of amino acids but also of purines, peptides, N-acetylated amino acids and peptides, and probably other compounds. This method has yielded important information such as the identification of two new diseases, GABA transaminase deficiency and adenylosuccinase deficiency, and the discovery of a peculiar, acid-labile double peak in the CSF of patients with the transient neonatal hyperammonaemia syndrome and with urea cycle defects. This substance was subsequently identified by others as -glutamylglutamine. As a consequence, we strongly recommend incorporating of this approach in the investigation of all children with unclear neurological disease.     

侧柏叶乙酸乙酯提取物对豚鼠离体气管平滑肌的作用

用离体豚鼠气管条,探讨侧柏叶乙酸乙酯提取物对气管平滑肌作用。结果表明,侧柏叶乙酸乙酯提取物能抑制乙酰胆碱,氯化钾所致气管平滑肌收缩,而且能使乙酰胆碱收缩气管平没肌的量效曲线右移,并抑制最大效应,其作用为剂量依赖性心肌肥厚提示侧柏叶乙酸乙酯提取物松驰气管平滑肌作用机制可能与影响Ｃａ＾２＋的跨膜转运有关。     

CAMs and FGF cause a local submembrane calcium signal promoting axon outgrowth without a rise in bulk calcium concentration

Binding of basic fibroblast growth factor (bFGF) and cell adhesion molecules to the nerve cell membrane promotes axon outgrowth. This response can be blocked by antagonists of voltage-gated calcium channels, yet no change of cytosolic calcium concentration in the growth cone can be detected upon binding of the growth factor bFGF or the cell adhesion molecule L1. Using barium as a charge carrier, we show that bFGF and L1 open a calcium influx pathway in growth cones of rat sensory neurons without changing the membrane voltage. L1 does not activate influx in cells expressing a dominant negative mutant of the fibroblast growth factor receptor (FGFR) tyrosine kinase. FGFR-activated influx is blocked by specific antagonists of L- and N-type voltage-gated calcium channels and by an inhibitor of diacylglycerol lipase. We propose that both L1 and bFGF act via the FGFR to generate polyunsaturated fatty acids which in turn cause calcium channels to flicker open and shut. Short-lived domains of raised calcium at the cytosolic mouth of open channels activate axon outgrowth without raising bulk cytosolic calcium concentration. In confirmation of this model, the rapidly-acting calcium buffer BAPTA is significantly more effective at blocking FGF-induced axon outgrowth when compared with the slower buffer EGTA. Generation of short-lived calcium domains may provide a crucial mechanism for axon guidance during development and for promoting regeneration of damaged axons.     

Orbital infarction and melting in a patient with systemic lupus erythematosus

OBJECTIVE: To present a patient with systemic lupus erythematosus who developed infarction and melting of the orbit secondary to her systemic disease. DESIGN: A case report. PARTICIPANT: A 61-year-old white woman with a 5-year history of systemic lupus erythematosus. METHODS: The patient presented with left orbital pain, limitation of extraocular movements, and a fistula from the ethmoid sinus to the upper eyelid. A detailed examination with computerized tomography, ultrasound, and a comprehensive medical evaluation with laboratory testing was performed. Histopathologic analysis with special stains of the orbital tissues was also performed. RESULTS: Histopathologic examination of the biopsy specimens revealed the features of an inflammatory process involving the orbit, similar to a panniculitis. These include a lymphocytic reaction with a predominance of plasma cells, vasculitis with occlusion, and thickening of the vessel walls, necrosis, and hyalinization of fat. CONCLUSION: This is a unique case in which infarction and melting of the entire orbital structures occurred in the presence of systemic lupus erythematosus. The underlying disease process is a lupus-related panniculitis. The authors stress that this is a very rare entity and that other diseases should be ruled out before entertaining this diagnosis.     

槐角的避孕成分研究(Ⅱ)——化合物Ⅴ～Ⅷ的分离和鉴定

本文报道从槐角中分离到的化合物Ⅴ～Ⅷ的鉴定。经紫外、核磁共振光谱分析及物理化学常数的测定,证明化合物Ⅴ～Ⅷ分别为山萘酚-3-槐糖甙、染料木素-7-双葡萄糖甙、山萘酚-3-鼠李糖-双葡萄糖甙和染料木素-7-双葡萄糖-鼠李糖甙。这些甙水解后的甙元山萘酚和染料木素对小鼠具有抗生育活性。     

Pharmacokinetics of methotrexate in leukemia cells: Effect of dose and mode of injection

A lumped compartmental model has been derived to predict methotrexate concentration as a function of time for L1210 cells in BD2F ₁ female mice at doses ranging from 3 mg/kg to 400 mg/kg. Using standard methods of parameter estimation as well as experimental determinations, an integrated approach was derived to account for the differences between the subcutaneous (s.c.) and intraperitoneal (i.p.) modes of injection. It was found that a single generalized forcing function can be used to fit plasma concentration after s.c. injection for all doses. Adequate fits (average error<20% while the standard deviation of experimental determinations was±22%) of L1210 cell data after s.c. injection were obtained. The best results were for a maximum facilitated influx constant V_max of 0.424 g/min/ml, a Michaelis influx constant K_m of 1,42 g/ml, and a first-order efflux constant of 0.047 min^–1.The model simulations were not sensitive to V_max, K_m,and so long as the ratio V_max/was approximately 9g/ml. The values of V _max ,K _m ,and which were obtained from our analysis of the in vivodata can be explained on the basis of previously performed in vitroexperiments. The parameters obtained from modeling the s.c. data were then applied for i.p. injection data. The resulting fits were adequate (average error<20% while the standard deviation of experimental determinations was±22%). A single generalized forcing function for drug concentration in the peritoneal cavity after i.p. injection for all doses was derived. The application of these results enables the prediction of methotrexate concentration in neoplastic cells at other doses after either s.c. or i.p. injection.     

Focal segmental membranous glomerulonephropathy associated with other glomerular diseases

In four patients with the nephrotic syndrome, renal biopsy revealed focal segmental membranous glomerulonephropathy (FSMGN) associated with the histologic patterns of "nil" disease (two cases), hereditary nephritis and diffuse diabetic glomerulosclerosis. The occurrence of FSMGN in association with other glomerular diseases, presumably unrelated to immune complex deposition, is infrequent in our experience. Rather than necessarily representing an early stage or milder form of membranous glomerulonephropathy, it may be an epiphenomenon. This interpretation has prognostic and therapeutic implications and raises important pathogenetic questions. In particular, this study suggests that in some instances, preexisting functional and structural abnormalities may play a role either in the deposition of preformed circulating immune complexes or in the local formation of immune complexes.     

Subtotal colectomy for obstructing carcinoma of the left colon

This retrospective review of seven patients with completely obstructing cancers of the left half of the colon, in addition to other reports in the literature, suggests that subtotal colectomy with primary ileal

1 Clinical data on seven patients who underwent subtotal colectomy for obstructing carcinoma of the left colon: 1975–1982.

Patient	Age (yr) and Sex	Tumor Location	Hospital Stay	Comments
1	68, F	Decending	10 days	A and W 40 mo postop1
2	71, F	Sigmoid	22 days	A and W 18 mo postop
3	73, F	Sigmoid	…	A and W 5 yr postop
4	66, F	Decending	8 mo	Dead from complications
5	72, M	Sigmoid	11 days	Incidental cecal cancer; A and W 3 mo postop
6	66, M	Sigmoid	28 days	Alive with metastasis 16 mo postop
7	78, M	Left transvers	34 days	Many other polyps; A and W 9 mo postop

1

A and W = alive and well.

proctostomy may be the treatment of choice for those lesions that are technically resectable and located high enough to permit an intraperitoneal ileal proctostomy. The morbidity and mortality is less than that seen with the staged approach and the length of hospitalization is shorter. By eliminating a second or third hospitalization and a temporary colostomy, palliation is better in those patients who ultimately die from recurrent cancer. Furthermore, those patients resected for cure may have increased rates of long-term survival.     

The ONG capsular lens,report of 100 implantations

This Capsular Lens (ONG, type IV, to be called O.C.L.) has been developed for routinely performed extracapsular cataract extraction with lens implantation. The fundamental surgical procedure was based on continuing experience with the bimanual aspiration-irrigation technique and system developed by the author in 1971. The biomechanical properties of the asymmetric partly flexible, haptic loops are designed to give tensionfree fixation in two capsular pockets. The plano-anterior position of the lens ensures well-defined irido-lenticular clearance and proper alignment of the convex side with the posterior capsule. Consequently no iridectomy or iridotomy is needed for proper aqueous flow.