Angiogenin antagonists prevent tumor growth in vivo

A noncytotoxic neutralizing monoclonal antibody (mAb), 26-2F, to human angiogenin (Ang), a potent inducer of neovascularization, has been reported to prevent or delay the establishment of HT-29 human tumor xenografts in athymic mice. In the present study the tumor model was modified to increase sensitivity to Ang antagonists to facilitate further investigations and comparisons of their capacity to inhibit tumor growth. An increase in the percentage of tumor-free mice from 10-25% to 65% is observed in this modified model after treatment with mAb 26-2F. An additional neutralizing mAb, 36u, that interacts with a different epitope on Ang similarly prevents the appearance of tumors, both alone and in combination with mAb 26-2F. In those tumors that develop in mice treated with these agents, the number of vascular elements is reduced. Actin, an Ang antagonist that unlike the mAbs binds both human and mouse Ang, also prevents the establishment of tumors while exhibiting no toxic effects at daily doses > 50 times the molar amount of circulating mouse Ang. Ang antagonists also inhibit the appearance of tumors derived from two other Ang-secreting human tumor cell lines--i.e., A549 lung adenocarcinoma and HT-1080 fibrosarcoma. These results demonstrate that inhibition of the action of Ang is an effective therapeutic approach for the treatment of malignant disease.     

Recent advances in molecular recognition and signal transduction of active peptides: receptors for opioid peptides

1. Opioid peptides are a family of structurally related neuromodulators which play a major role in the control of nociceptive pathways. These peptides act through membrane receptors of the nervous system, defined as mu, delta and kappa and endowed with overlapping but distinct pharmacological, anatomical and functional properties. 2. Recent cloning of an opioid receptor gene family has opened the way to the use of recombinant DNA technology at the receptor level. 3. This review focuses on the molecular cloning and functional characterization of opioid receptors and provides first insights into molecular aspects of opioid peptide recognition and signal transduction mechanisms, using the cloned receptors as investigation tools.     

Magnetic resonance imaging protocol optimization for evaluation of hyaline cartilage in the distal interphalangeal joint of fingers

RATIONALE AND OBJECTIVES: To identify a single magnetic resonance imaging (MRI) protocol that will provide optimal signal-to-noise ratio, resolution, and image contrast with minimal susceptibility artifacts and that will allow clear delineation and visualization of cartilage, fluid, bone, tendons, and ligaments within the distal interphalangeal (DIP) joint of the human hand. METHODS: A highly optimized 2.4 T MRI system was constructed from a 31-cm horizontal bore magnet, using a solenoid radiofrequency coil. This was used to study the DIP joints of 16 healthy, asymptomatic volunteers. RESULTS: A range of image contrast protocols were explored, including spin-echo T1 and T2, field echo, chemical shift suppression to give water only images, and magnetization transfer. Susceptibility variations were explored by changing the field strength from 0.6 to 2.4 T. A spin-echo protocol with TR = 1500 msec and TE = 30 msec can routinely produce images with resolution 0.075 x 0.150 for a slice thickness of 1 mm in 13 minutes. That protocol can visualize simultaneously compact and trabecular bone, two layers of cartilage, synovial fluid, and synovium within the joint, tendons and ligaments, and the volar plate. CONCLUSIONS: Although the contrast is not fully optimized for any one tissue, the spin echo protocol (TR = 1500, TE = 30) provides sagittal MR images, which clearly delineate the major structures of interest within the DIP joint, and which will be used in future studies to compare changes in the DIP joint because of aging or osteoarthritis. Experience gained by applying the above methods to a total of 16 healthy, asymptomatic volunteers has enabled a single sequence to be identified, which although not optimized for any one tissue, nevertheless visualized simultaneously and clearly delineated compact and trabecular bone, two layers of cartilage, synovial fluid, and synovium within the joint.     

X-ray-induced secondary-electron emission from solid xenon

The time has come for the creative professional structural engineers to prepare themselves for the challenges of designing permanent structures on the moon. This paper briefly discusses creativity in structural engineering, and its applicability on lunar structures. It then describes development of the concept of a lunar structure, that is optimized under the present state of technology to meet every requirement of function, economy and safety. The concept envisions the lunar structure to be constructed of double‐skin composite fabric membrane which is filled with structural foam for pressurized or unpressurized applications. Such a structure will be extremely light and easy to transport, readily deployable, economical, and can be made in almost any size, shape and height to suit the purpose for which it is designed.     

The superior approach for correction of the supracardiac type of total anomalous pulmonary venous return

An alternative approach for correction of supracardiac (type I) total anomalous pulmonary venous return is described. A median sternotomy is used. The posterior wall of the left atrium and the common pulmonary venous trunk are exposed through the transverse sinus. A direct anastomosis between these structures, ligation of the systemic-venous connection (vertical vein), and closure of the interatrial septal defect results in a one-stage repair. In our experience with the supracardiac anomaly in 20 patients, we have found that this approach consistently affords better exposure than other techniques currently in use for surgical correction of this anomaly.