Search PubMed⌕ Search

Biomedical subjects

R Henderson

Publications and source records attributed to R Henderson.

At least 199 records · Page 11Linked to original sources
PubMed1980

Orthorhombic two-dimensional crystal form of purple membrane.

A new two-dimensional crystal form of purple membrane has been obtained in vitro. It is produced by the joint use of a cationic detergent, dodecyltrimethylammonium chloride, and the nonionic detergent, Triton X-100. It primarily forms large, rolled-up sheets that look like needles in the light microscope. Liposomes and tubes are also observed. The absorption maximum of the new form of purple membrane is blue-shifted by 6 nm and its density is slightly lower than the natural form of purple membrane. The new form of purple membrane is orthorhombic with space group p22121 and cell dimensions 57.6 x 73.5 A. Four molecules of bacteriorhodopsin occupy the unit cell with an area per molecule close to that found in the native p3 structure. The projected structure to 6.5-A resolution was determined by electron microscopy and diffraction. It shows an identical molecular structure to that of the p3 form and determines the position of the polypeptide boundary.

Bacteriorhodopsins↗
PubMed1980

Path of the polypeptide in bacteriorhodopsin.

An attempt has been made to fit the amino acid sequence of bacteriorhodopsin to the three-dimensional density map of the molecule. First, seven segments of the sequence were selected as being probable transmembrane alpha helices. Then each of the 5040 possible ways of fitting these seven segments into the seven regions of helical density in the map were evaluated based on the criteria of connectivity of the nonhelical link regions, charge neutralization, and total scattering density per helix. A single model that may be experimentally tested emerged as the most probable.

Bacteriorhodopsins↗
PubMed1980

CT of inflammatory disease of the psoas muscle.

Computed tomography (CT) findings in eight cases of psoas inflammatory disease are described retrospectively. Because of its exquisite retroperitoneal imaging capabilities, CT proved to be an ideal tool in evaluating suspected disease in this area. Clinically, the deep position of psoas abscesses has made diagnosis problematic. In addition, many radiographic signs of psoas inflammation have provided only indirect evidence, such as displacement of the ureter or alteration of the psoas margin. The organ-specific information available with CT makes detection more efficient and diagnosis more certain. Especially when coupled with percutaneous aspiration biopsy, CT has proved an effective and rapid means of diagnosing and guiding the therapy of psoas abscess.

Abscess↗
PubMed1979

Comparison of left ventricular ejection fraction by EKG-gated radionuclide techniques and contrast angiography using a microcomputer system.

The left ventricular ejection fractions of 53 patients were determined from multi-image cardiac blood pool scintigrams in the left anterior oblique position utilizing a microcomputer and floppy disc. These data were compared to ejection fractions obtained at cardiac catheterization in the right anterior oblique position. The ejection fraction obtained by radionuclide technique was comparable to that obtained by contrast angiography in the 53 patients with an r = 0.93. Forty-five patients with coronary artery disease showed an r = 0.92. In the coronary artery group with regional wall dysfunction, the correlation was r = 0.89.

Angiography↗
PubMed1979

First-pass or single-pass radionuclide angiography evaluation of left ventricular ejection fraction using a microcomputer system.

Left ventricular ejection fractions of 31 patients determined from first-pass or single-pass radionuclide angiography from the anterior position using a microcomputer system and floppy disc were compared to angiographic catheterization data obtained from the right anterior oblique position. This study demonstrated a good correlation with r = 0.91. To our knowledge, this is the first report of comparative first-pass left ventricular ejection fraction data and contrast angiography using a microcomputer system and a floppy disc.

Albumins↗