Ligand-induced homotypic and heterotypic clustering of apolipoprotein E receptor 2.

ApoE Receptor 2 (ApoER2) and the very low density lipoprotein receptor (VLDLR) are type I transmembrane proteins belonging to the LDLR family of receptors. They are neuronal proteins found in synaptic compartments that play an important role in neuronal migration during development. ApoER2 and VLDLR bind to extracellular glycoproteins, such as Reelin and F-spondin, which leads to phosphorylation of adaptor proteins and subsequent activation of downstream signaling pathways. It is thought that ApoER2 and VLDLR undergo clustering upon binding to their ligands, but no direct evidence of clustering has been shown. Here we show strong clustering of ApoER2 induced by the dimeric ligands Fc-RAP, F-spondin, and Reelin but relatively weak clustering with the ligand apoE in the absence of lipoproteins. This clustering involves numerous proteins besides ApoER2, including amyloid precursor protein and the synaptic adaptor protein PSD-95. Interestingly, we did not observe strong clustering of ApoER2 with VLDLR. Clustering was modulated by both extracellular and intracellular domains of ApoER2. Together, our data demonstrate that several multivalent ligands for ApoER2 induce clustering in transfected cells and primary neurons and that these complexes included other synaptic molecules, such as APP and PSD-95.

Gross, histological and ultrastructural morphology of the aglomerular kidney in the lined seahorse Hippocampus erectus.

Histologic evaluation of the renal system in the lined seahorse Hippocampus erectus reveals a cranial kidney with low to moderate cellularity, composed of a central dorsal aorta, endothelial lined capillary sinusoids, haematopoietic tissue, fine fibrovascular stroma, ganglia and no nephrons. In comparison, the caudal kidney is moderately to highly cellular with numerous highly convoluted epithelial lined tubules separated by interlacing haematopoietic tissue, no glomeruli, fine fibrovascular stroma, numerous capillary sinusoids, corpuscles of Stannius and clusters of endocrine cells adjacent to large calibre vessels. Ultrastructural evaluation of the renal tubules reveals minimal variability of the tubule epithelium throughout the length of the nephron and the majority of tubules are characterized by epithelial cells with few apical microvilli, elaborate basal membrane infolding, rare electron dense granules and abundant supporting collagenous matrix.

Phacoemulsification devices: a consumer's report.

This report deals with our evaluation of six phacoemulsification devices tested at the Neumann Eye Institute (two additional devices have been evaluated since this paper was presented at the ASCRS meeting). The devices were compared for operating cost of the first 1,000 cases, dependability, ease of usage, and level of safety for the patient.

Phacoemulsification devices: a consumer's update.

This report extends a previous paper on the various characteristics of the most popular phacoemulsification devices. An evaluation of 11 devices by ten different manufacturers was attempted. Only five manufacturers of six devices agreed to critical evaluation or reevaluation. As in the previous report, the devices were compared for level of patient safety, dependability, efficiency, ease of usage, and operating cost for the first 1,000 cases. At the completion of this study, we ranked the nine devices evaluated over the past 17 months as follows: (1) United Surgical (Optikon) Systems Plus, (2) Optical Micro Systems (OMS), (3) United Surgical (Optikon) Phacotron, (4) CooperVision 10,000, (5) Site XTR, (6) CooperVision KCP, (7) CooperVision 9001, (8) Phakosystems CES 4000 and (9) United Sonics. To enhance the usefulness of this consumer's guide, we asked 40 experienced cataract surgeons what they wanted in the "ideal" phacoemulsification device. The opinions of 27 who responded are included.

Fyn tyrosine kinase increases Apolipoprotein E Receptor 2 levels and phosphorylation.

Apolipoprotein E Receptor 2 (ApoER2) and the tyrosine kinase Fyn are both members of the Reelin pathway, a signaling pathway essential for the laminar formation of the cortex during development and proper dendritic spine density and long-term potential (LTP) in the adult brain. In the presence of extracellular Reelin, ApoER2 binds the intracellular protein Dab1, an adaptor protein that is phosphorylated by Fyn. However, direct interactions between ApoER2 and Fyn are not well defined. Here, we show that total levels of ApoER2 and surface levels of ApoER2 are increased by active Fyn. Via a separate mechanism, ApoER2 is also phosphorylated by Fyn, an event that peaks in the postnatal cortex at day 5 and can occur at multiple ApoER2 tyrosine residues. Dab1 is also involved in this phosphorylation, promoting the phosphorylation of ApoER2 by Fyn when it is itself phosphorylated. These results elucidate some of the intracellular mechanisms that give rise to a functional Reelin pathway.

Breast-specific gamma imaging as an adjunct modality for the diagnosis of invasive breast cancer with correlation to tumour size and grade.

OBJECTIVES: The purpose of this study was to determine the sensitivity of breast-specific gamma imaging (BSGI) in the detection of invasive breast cancers and to characterise the sensitivity of BSGI based on tumour size and pathological grade. METHODS: 139 females with invasive carcinoma who underwent BSGI were retrospectively reviewed. Patients were injected in the antecubital vein with 20-30 mCi (925-1110 MBq) of (99m)Tc-sestamibi. Images were obtained with a high-resolution, breast-specific gamma camera (Dilon 6800; Dilon Technologies, Newport News, VA) and were categorised based on radiotracer uptake as normal, normal with heterogeneous uptake, probably abnormal and abnormal. For a positive examination, the region of the area of increased uptake had to correlate with the laterality and location of the biopsy-proven cancer. RESULTS: 149 invasive cancers in 139 patients with a mean size of 1.8 cm (0.2-8.5 cm) were included. 146 were identified with BSGI (98.0%). All cancers which measured ≥ 0.7 cm (n = 123) as well as all cancers grade 2 or higher (n = 102), regardless of tumour size, were identified with BSGI (100%). There were 6 cancers that were pathological grade 1 and measured <7 mm, of which 50% (3/6) were identified with BSGI. The overall sensitivity of BSGI for the detection of invasive breast cancer is 98.0%. The sensitivity for subcentimetre cancers is 88.5% (23/26). CONCLUSION: BSGI has a high sensitivity for the detection of invasive breast cancer. Our results demonstrate that BSGI detected all invasive breast cancers pathological grade 2 and higher regardless of size and all cancers which measured ≥ 7 mm regardless of grade. BSGI can reliably detect invasive breast cancers and is a useful adjunct imaging modality for the diagnosis of breast cancer.

Structure of 240Pu: evidence for octupole phonon condensation?

The expanded level structure of 240Pu available from the present study highlights the role of strong octupole correlations in this nucleus. In addition to a delayed alignment in the yrast band, the observations include the presence of both I(+)-->(I-1)(-) and I(-)-->(I-1)(+)E1 transitions linking states of the yrast and negative-parity bands at high spin and the presence of an additional even-spin, positive-parity band deexciting exclusively to the negative-parity sequence. The observations appear to be consistent with expectations based on the recently proposed concept of octupole phonon condensation.

p-sd Shell gap reduction in neutron-rich systems and cross-shell excitations in 20 O.

Excited states in 20O were populated in the reaction 10Be(14C,alpha) at Florida State University (FSU). Charged particles were detected with a particle telescope consisting of 4 annularly segmented Si surface barrier detectors and gamma radiation was detected with the FSU gamma detector array. Five new states were observed below 6 MeV from the alpha-gamma and alpha-gamma-gamma coincidence data. Shell model calculations suggest that most of the newly observed states are core-excited 1p-1h excitations across the N=Z=8 shell gap. Comparisons between experimental data and calculations for the neutron-rich O and F isotopes imply a steady reduction of the p-sd shell gap as neutrons are added.

Education improves colorectal cancer screening by flexible sigmoidoscopy in an inner city population.

OBJECTIVE: The District of Columbia General Hospital has a flexible sigmoidoscopy (FS) colorectal cancer screening program. We noted that this program was underused. The aim of this study was to determine whether education could improve use of a flexible sigmoidoscopy screening program in an inner city population. METHODS: Patients undergoing screening FS 5 months before our educational initiative were compared to patients undergoing screening FS 5 months after implementation. A 1-month period was allowed for implementation. Procedure logs and GI charts were reviewed. RESULTS: A total of 121 patients underwent FS screening during our study period. Of the patients, 97% were African-American; 58% were female; and the average age was 61 yr. A total of 50 patients underwent FS in the pre-education group, and 71 patients underwent FS after implementation of our educational initiative. CONCLUSIONS: Education resulted in a 42% increase in FS screening in this inner city, predominantly African-American population. Larger scale educational initiatives should be conducted to determine whether these benefits can persist and can be improved upon.