摘要:

SummaryA monoclonal antibody, MI/N1, is described that reacts predominantly with fresh neuroblastoma tissue, human neuroblastoma cell lines, and cells of the myeloid lineage. Investigation of the binding of this antibody to four different neuroblastoma cell lines showed CHP 100 bound approximately 4 times more antibody than CHP 126. Only 30% of the cells in the line CHP 100 bound MI/N1 as determined by indirect immunofluorescence. Thus, both quantitative and qualitative differences in the expression of antigen recognised by MI/N1 are detected on human neuroblastoma cell lines. Inasmuch as only five of eight marrow aspirates heavily infiltrated with neuroblasts bound the monoclonal, this also suggests a heterogeneity in antigenic expression on fresh tumour cells. Absorption studies indicate that the antigen recognised by MI/N1 is present on human foetal brain and adult human cerebellum. At a dilution of 1/750, equal volumes of foetal brain and adult cerebellum absorbed out 30 and 60% of the reactivity to the human neuroblastoma cell line CHP 100. No reactivity was found towards murine neuroblastoma cells or rat brain.Expression of antigen on cells in the myeloid lineage appears dependent upon their stage of maturation, increasing as cells mature to neutrophils and eosinophils.It is suggested that the quantitative and qualitative differences seen in the expression of antigen on neuroblastoma cells may relate to their being blocked at different stages of differentiation.

ISSN:0031-3998    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

SummaryInasmuch as human monocytes are able to killCandida albicans (C. albicans)only through oxidative pathways, which also produce chemiluminescence (CL), CL was used to assess the ability of polymorphonuclear neutrophils and monocytes to phagocytose and killC. albicansin a 12-year-old girl with chronic mucocutaneous candidiasis.In contrast to normal mononuclear cells (monocytes and lymphocytes), mononuclear cells from the patient did not respond with a CL burst when mixed with opsonizedC. albicans(peak CL, 55versus105 cpm x 10-3for control). Phagocytosis ofC. albicansby monocytes, assessed by electron microscopy, was normal. The patient's mononuclear cells did produce CL when mixed withCandida parapsilosis(peak CL, 68versus72 cpm x 10-3for control) or zymosan (peak CL, 149versus180 cpm x 10-3for control). Myeloperoxidase activity in monocytes assessed by light microscopy was normal. However, peroxidase activity in the patient's monocytes persisted in glass-adherent monocyte-macrophages after 5 days incubation, suggesting that her cells may mature poorly.In contrast to the poor CL response of monocytes toC. albicans, polymorphonuclear neutrophils from the patient had increased CL (peak, 858versus458 cpm x 10-3for control). Also, the patient's serum showed increased opsonic activity forC. albicans(peak, 1800versus1100 cpm x 10-3for control).

ISSN:0031-3998    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

SummaryAspirin administration, at a dosage producing plasma levels within the human therepeutic range, caused marked inhibition of production of both vascular prostacyclin (a vasodilator) and platelet thromboxane (a vasoconstrictor) in beagle puppies. In addition, aspirin-treated, oxygen-exposed puppies developed retinopathy of significantly greater severity than their unmedicated, oxygen-exposed littermates. Direct ophthalmoscopic observations indicated that whereas sustained oxygen breathing produced retinal vasoconstriction in unmedicated puppies, retinal vessels of aspirintreated littermates became more dilated or remained unchanged. It is postulated that retinal vasoconstriction may be a normal physiologic mechanism to protect the immature retina from damaging effects of high blood oxygen levels;i.e., it may be a protective rather than a pathologic process in response to hyperoxia.Many vascular anomalies which characterize the human disease were present in the retinas of the puppies. Several of the most severely affected puppies treated with aspirin even displayed grade III cicatricial retinopathy (falciform retinal fold). Thus, a major criticism of the retrolental fibroplasia animal model has been addressed by producing cicatricial retrolental fibroplasia in puppies, and the confidence with which results from experimental animal studies might be extrapolated to the clinical situation is thereby strengthened.

ISSN:0031-3998    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

Summary125I-Tyr insulin (125I-Tyr Ins) was injected into the vitelline vein of rat fetusesin uteroafter 17, 19, or 21 days of gestation. Three min later, the weight and radioactivity of various organs and of the remaining carcass were measured. A radioactivity concentration index (RCI) was calculated by dividing the specific activity of each organ by that of the whole feto-placental unit. In each of the three age groups studied, the RCI indicated that125I-Tyr Ins was concentrated in several organs, notably the liver and kidneys. The lungs also concentrated the labeled hormone; however, only the youngest fetuses revaled significantly elevated levels. Lung RCIs were 1.68 ± 0.27, 0.67 ± 0.12, and 0.85 ± 0.18 after 17, 19, and 21 days of gestation, respectively. Three, 9 and 15 min after125-I-Tyr Ins injection, the lungs and liver of 17-day postcoitum fetuses were homogenized and then subjected to gel chromatography. During the 15 min period of investigation, the percentage of intact labeled hormone in the liver and lungs decreased while the percentage of125I-tyrosine increased.Autoradiographs of the fetal lungs indicated that the pseudoglandular cells bound125I-Tyr Ins (surface density of grains 9 min after125I-Tyr Ins alone, 1.71 ± 0.22) and that this process was inhibited by coinjection of 100 mU unlabeled insulin (surface density of grains, 0.50 ± 0.16;P< 0.001). At 9 min, the surface density of grains on the bronchial tubes was only six times less than that of the hepatocytes of the same fetuses. It was concluded that epithelial lung cells during the pseudoglandular stage are equipped with numerous insulin receptors and appear capable of degrading insulin. The concentration of receptors markedly decreased at a later stage of lung development.

ISSN:0031-3998    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

SummaryAlterations in the pancreatic secretion of fluid and of enzymes in response to either pilocarpine (15 mg/kg) or an octapeptide of cholecystokinin (0.1 μg/kg) have been found in rats that received daily injections of reserpine (0.5 mg/kg) for 7 days. During a 3-hr secretory period, significant reductions in the volume of pancreatic juice and in the total output of protein, amylase, and trypsin were observed in these animals. In the first hour of the secretory response, however, protease output was increased in the treated animals, particularly that of chymotrypsin, which was also increased in the longer secretory period following pilocarpine, but not cholecystokinin, stimulation. Zymogen granules isolated from the pancreas of the treated rats by differential centrifugation in a 0.3 M sucrose buffer had increased specific activities of the proteases when compared to those of untreated controls. Ultra-structurally, zymogen granules isolated from the pancreas of the treated rats showed changes in density, with bizonal and trizonal configurations being frequently observed, and had less distinct limiting membranes. In some, the membrane appeared broken at intervals, and there was granular material, presumably derived from the granule contents, lining the surface of the granule. It is concluded that pretreatment with reserpine inhibits fluid secretion and alters enzyme secretion in the rat exocrine pancreas. The latter effect is related to a nonparallel storage of amylase and proteases in the secretory granules induced by the drug treatment, probably through an action on protein synthesis or intracellular transport. An accumulation of proteases may lead to activation of these enzymes and to granule lysis. Inasmuch as the reserpinetreated rat has been proposed as an experimental model for cystic fibrosis, these findings are relevant in terms of possible pathogenetic mechanisms in this disease.

ISSN:0031-3998    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

SummaryWe investigated concanavalin A capping that occurred either spontaneously (neutrophils incubated only with buffer) or was drug induced (neutrophils with colchicine or diamide) using neutrophils obtained from the blood of newborn infants and their mothers. A greater proportion of infant and maternal neutrophils than controls formed caps spontaneously (P< 0.01). The percent of capped neutrophils (mean ± S.E.) for 24 infants and their mothers was 23 ± 3 and 39 ± 4, respectively,versus13 ± 2 for 26 controls. Spontaneous capping was significantly decreased when neutrophils were incubated with catalase and superoxide dismutase to suggest that it was related, at least in part, to oxidation. Drug-induced capping of infant and maternal neutrophils was decreased when compared to controls (P< 0.05). Colchicine increased capping of control neutrophils 11.76-fold above the spontaneous value, whereas capping of infant and maternal cells was increased only 2.35− and 1.65-fold. Corresponding values for diamide were 11.94-, 2.27-, and 2.49-fold for control, infant, and maternal neutrophils, respectively. Many cellular processes are involved in capping, and the mechanisms responsible for aberrant capping of infant neutrophils remain undefined. However, this is another property that distinguishes infant neutrophils from those of older individuals.

ISSN:0031-3998    

出版商:OVID    

年代:1981

数据来源: OVID