Criterion for biholomorphic equivalence of isolated hypersurface singularities

Two germs of complex analytic hypersurfaces with isolated singularities are biholomorphically equivalent if and only if they have the same dimension and their moduli algebras are isomorphic.     

The relationship between the diameter of chemically-functionalized multi-walled carbon nanotubes and their organ biodistribution profiles in vivo

Carbon nanotubes (CNTs) exhibit unique properties which have led to their applications in the biomedical field as novel delivery systems for diagnosis and therapy purposes. We have previously reported that the degree of functionalization of CNTs is a key factor determining their biological behaviour. The present study broadens the spectrum by investigating the impact of the diameter of CNTs using two series of multi-walled CNTs (MWNTs) with distinct differences in their diameters. Both MWNTs were doubly functionalized by 1,3-dipolar cycloaddition and amidation reactions, allowing the appended functional groups to be further conjugated with radionuclide chelating moieties and antibodies or antibody fragments. All constructs possessed comparable degree of functionalization and were characterized by thermogravimetric analysis, transmission electron microscopy, gel electrophoresis and surface plasmon resonance. The MWNT conjugates were radio-labelled with indium-111, which thereby enabled in vivo single photon emission computed tomography/computed tomography (SPECT/CT) imaging and organ biodistribution study using γ-scintigraphy. The narrow MWNTs (average diameter: 9.2 nm) demonstrated enhanced tissue affinity including non-reticular endothelial tissues compared to the wider MWNTs (average diameter: 39.5 nm). The results indicate that the higher aspect ratio of narrow MWNTs may be beneficial for their future biological applications due to higher tissue accumulation.     

Identification of immunoreactive monoclonal antibody fragments for improved immunoscintigraphy

Results obtained in animal models suggest that antibody fragments may have advantages over whole immunoglobulin for in vivo localisation studies. Proteolytic digestion of monoclonal antibodies may however yield a mixture of products unsuitable for in vivo use. This report describes a method whereby the immunoreactive products of antibody digestion can be identified by probing nitrocellulose blots of the gel-separated digest with the specific antigen. Optimum conditions for the production of the reactive fragments can then be determined and once identified they can be purified to homogeneity. Using this method conditions have been defined for the production of F(ab)2 and Fab fragments from a papain digest of an antibody to placental alkaline phosphatase (H17E2). In this case the antigen has enzyme activity which can be used to detect binding to the immunoreactive bands on the Western blots. In vivo experiments in nude mice carrying xenografts of a tumour expressing the H17E2 reactive antigen were performed to determine the efficacy of localisation of the purified fragments as compared to the whole antibody. As expected the absolute levels of radioactivity localised in the tumour was highest using whole antibody, whereas the F(ab)2 fragments produced the highest tumour:blood ratios.     

Efficacy of community-based second trimester genetic ultrasonography in detecting the chromosomally abnormal fetus.

We sought to assess prospectively the efficacy of community-based genetic ultrasonography in detecting chromosomally abnormal fetuses in a high-risk population and determine independent markers of aneuploidy. Patients 18 years old and older who were between 14 and 24 weeks' gestation were included if referred for maternal age greater than 35 years, increased risk of Down syndrome or trisomy 18 by second trimester serum screen, or prior affected offspring. All women had a targeted ultrasonographic examination between April 1997 and June 1999 and were offered fetal chromosomal analysis. Markers of aneuploidy and pregnancy outcomes were recorded prospectively. The primary outcome was prenatally or postnatally detected chromosomal abnormalities. Of the 1030 fetuses seen during the study, 789 had outcome data available and constituted the study group. In this group, 694 (87.9%) ultrasonograms were normal, 73 (9.2%) had one marker present, 17 (2.2%) had two markers present, and 5 (0.6%) had three or more markers present. Fourteen of 17 (82.3%) aneuploid fetuses had an abnormal ultrasonogram (one or more markers present), including 5 of 7 (71.4%) with Down syndrome. Logistic regression showed abnormal four-chamber view, structural anomaly, and intracardiac echogenic focus to be significant aneuploidy markers. The amniocentesis rate was 334 of 1030 (32.4%), and it increased with the number of sonographic markers noted (0 = 29.9%, 1 = 60.2%, 2 = 70.6%, 3 or more = 80%). Genetic ultrasonography is highly effective in identifying chromosomally abnormal fetuses in a community-based practice.