The N-domain of the biliary glycoprotein (BGP) adhesion molecule mediates homotypic binding: domain interactions and epitope analysis of BGPc

The biliary glycoproteins (BGPs) represent a group of at least eight differentially spliced molecules belonging to the carcinoembryonic antigen (CEA) subgroup of the CEA family. These molecules are recognized by the CD66 monoclonal antibodies (MoAbs) and function as homotypic and heterotypic adhesion molecules. The extracellular region of the BGPc splice variant comprises an N-terminal IgV-like domain and three IgC2-set domains (A1, B1, and A2). Using soluble recombinant BGP domain variants, we demonstrate in this report that the N-terminal domain mediates homotypic adhesion. Furthermore, this adhesion is both temperature- and cation-dependent. The soluble domain variants of BGP are ideal molecules for epitope mapping. Using these constructs, we have mapped 11 MoAbs that react with the CEA family to different domains of BGPc and have shown that the CD66 MoAbs, YTH71.3.2 and CLBgran 10 (M38), recognize epitopes in the N-terminal domain.     

Current status of positron emission tomography in oncology

Positron emission tomography (PET) has emerged as a powerful diagnostic tool in oncology patients. There is evidence of the superior utility over conventional imaging methods of the principal PET tracer ¹⁸F‐fluoro‐2‐deoxy‐glucose in the staging of a range of cancers and monitoring disease recurrence, as well as changing patient management to more appropriate therapy. The methods for evaluating the evidence for PET remain complex, particularly as the standard evidence‐based approach of randomized controlled trials is not generally applicable to imaging technologies. PET has the potential to dramatically improve our ability to manage patients with cancer and is also making major contributions to the development of new therapies. (Intern Med J 2000; 31 : 27–36)     

Parents of children with neurofibromatosis 1: Comparison of maternal and paternal responses

The objectives of this qualitative study are: to explore ways in which women with positive and inconclusive breast and ovarian cancer (BRCA) genetic test results assign meaning, make interpretations, and respond to test results and recommendations for risk reduction and disease detection interventions; and to develop a grounded theory based on the perceptions, beliefs, and actions of these women. A grounded theory method has been used to study a theoretical sample of 30 women in North America with positive or inconclusive BRCA genetic test results, not diagnosed with breast or ovarian cancer. The findings will assist in the future design of nursing interventions to provide required information and ensure support for women making risk reduction and disease detection decisions after BRCA testing.     

Retained caudal catheter in a paediatric patient

We present a case of a retained sheared caudal catheter in which catheter retrieval was elected and performed with an uneventful recovery.     

Comparison of the effects of cyclosporine A and trimetazidine on Ca2+-dependent mitochondrial swelling

Summary— Cyclosporine A (CsA) is a known potent inhibitor of pro-oxidant-induced mitochondrial swelling. In the present study we show that CsA's effect is only transient when the liver mitochondrial swelling is induced by Ca²⁺ plus tert-butylhydroperoxide (t-BH). After an initial inhibition, swelling is worsened by CsA as evidenced by an extent of mitochondrial swelling that exceeds that of the control. Unlike CsA, trimetazidine (TMZ), an anti-ischemic drug decreases both the extent and the rate of the swelling with an IC₅₀ value of 214 ± 24 μM. Its inhibition effect on the initial swelling rate mimicks that of CsA but the mechanism may be independent. During long-term swelling, TMZ counteracts the worsening effect of CsA. The inhibition of swelling induced by TMZ is assessed by the fact that TMZ significantly increases the EC₅₀ of Ca²⁺-induced mitochondrial swelling (46.6 ± 6.0 to 85 ± 10 μM, P < 0.01), without affecting its cooperativity. Apparently, TMZ seems to behave like trifluoperazine (TIT), a phospholipase A₂ inhibitor that, under our experimental conditions, inhibits the mitochondrial swelling induced by Ca²⁺ and t-BH with an IC₅₀ value of 25 ± 10 μM. Both drugs are able to protect mitochondria from both phases (early and late) of the swelling, especially the late, which is enhanced in the presence of CsA. TFP and other phospholipase A₂ inhibitors were able to displace [³H]TMZ from its mitochondrial binding sites whereas CsA was ineffective. We suggest that TMZ, like TFP, inhibits the CsA insensitive mechanism involved in the swelling process which is responsible for the worsening effect observed in the presence of CsA when the swelling is generated by Ca²⁺ and t-BH.