Inhibition of Deamination of Arabinosylcytosine (NSC-63878) by Rhodium(II) Acetate

The nobel metal "cage" complex, rhodium(II) acetate, was found to inhibit the deamination of the fraudulent nucleoside, arabinosylcytosine. Potent inhibition of a purified cytidine deaminase from mouse kidney was observed when either cytidine or arabinosylcytosine was used as substrate.

Pulmonary granulomas in a patient with pulmonary veno-occlusive disease

A patient with pulmonary veno-occlusive disease is described. Lung biopsy revealed noncaseating granulomas in conjunction with the typical vascular changes of this entity. This concurrence has not been previously described.

Purification and properties of membrane-bound coupling factor-latent ATPase from Mycobacterium phlei

The membrane bound coupling factor-latent ATPase was solubilized from the membrane vesicles of Mycobacterium phlei by using 0.25 M sucrose or low ionic strength buffer. Purification of the solubilized enzyme by use of Sepharose-ADP conjugate gel yielded a homogenous preparation of latent ATPase which was purified about 216-fold in a single step with an 84% yield. The enzyme exhibits a specific activity of 39 mumoles of ATP hydrolyzed per min per mg protein. The purified enzyme exhibits coupling factor activity. Electrophoresis in two dissociating solvent systems indicates that the enzyme contains at least three major polypeptides of molecular weights 56,000, 51,000, and 46,000 daltons, and two minor polypeptides of 30,000 and 17,000 daltons. Equilibrium binding studies of ADP with purified coupling factor-latent ATPase reveal the presence of two nucleotide binding sites per molecule with an apparent Ka of 8.1 X 10(-5) M. By use of affinity chromatography, another latent ATPase has been isolated from the solubilized enzyme, which does not exhibit coupling factor activity.

Interferon-mediated increased lysis of L-cells by vesicular stomatitis virus

L-929 cells have been cultivated for more than 6 months in the presence of interferon. These L-cells, referred to as L-int cells, were found to be more susceptible to the lytic properties of vesicular stomatitis virus (VSV) than normal L-929 cells. This phenomenon has been demonstrated by the production of clear plaques as opposed to cloudy plaques as well as the increased release of cell incorporated 3H-thymidine after VSV infection. The L-int cells were also signicantly more susceptible than L-929 cells to the cytotoxic properties of DEAE-dextran, protamine sulfate, and methylated albumin.This interferon-induced change to L-cells is not stable. Increased susceptibility to VSV lysis is lost after 4–6 cell generations in the absence of interferon, and increased susceptibility to DEAE-dextran is lost after 16–24 cell generations in the absence of interferon. Moreover, the increased sensitivity to VSV lysis and polycation cytotoxicity can be induced after overnight treatment of L-929 cells with interferon.

Restoration of degraded images by composite gratings in a coherent optical processor

A study has been made on restoration of degraded images utilizing spatial filtering techniques in a coherent optical processor. This study differs from other coherent approaches in that the spatial filters employed contain only composite gratings that are quite simple to produce. A general method of synthesizing the appropriate composite gratings for the linearly smeared as well as multiply exposed and out-offocus images will be presented in some detail with experimental results. The extension of the method of synthesis to other types of degradation will be briefly discussed. in Appendix A.

Single step detection of blurred images in a coherent optical processor

Two important operations that can be performed by coherent optical processing systems are image detection and image restoration. These operations require complex spatial filters, and if both operations are to be performed, cascaded processing stages employing two separate spatial filters are usually needed. Spatial filters are described that will perform in a single step both operations simultaneously, thus eliminating the need of extra processing stages while providing the advantages of higher efficiency and smaller space requirements. The filters are characterized by their simplicity and are easily fabricated using conventional techniques. Experimental results are presented.

Isolation of parietal cells from glutaraldehyde-fixed rabbit stomach

A method is introduced to isolate and purify parietal cells from the rabbit stomach which has been briefly perfused with 1% glutaraldehyde via the celiac artery. The fixed mucosa is initially digested with 1% trypsin and subsequently with 1% collagenase solution. The parietal cells are more resistant to the effects of these proteolytic enzymes than the other cell types in the gastric mucosa and can be recovered and purified by centrifugation in a discontinuous sucrose gradient. Glutaraldehyde fixation reduces the tendency of cell clumping and, therefore, facilitates isolation of the separated cells. The final yield from each adult rabbit stomach varies from 0.1 to 0.4 ml packed parietal cells of about 97% purity determined by nuclear counts. The nuclei and mitochondria of most of the isolated cells appear to be intact on electron micrographs, but the cell membrane is focally disrupted; the nuclear deoxyribonucleic acid (DNA) can be stained with Feulgen technique and extracted with perchloric acid for quantitative determination. Biochemical studies on incorporation of thymidine-3H into DNA of the parietal cells have been carried out in normal young adult rabbits and in rabbits under chronic histamine stimulation. The results show that there is no significant incorporation of thymidine-3H by mature parietal cells in any of the two groups of animals, although the whole mucosa DNA hydrolysates always exhibit a high specific activity.

Interferon inhibition of DNA synthesis and cell division

Using monodispersed cell suspensions, interferon preparations were shown to have both a lethal and a growth-depression effect in the same concentration range as that required for antiviral activity. In addition, synchronized cells treated with interferon respond by delaying their normal uptake of thymidine during S phase until after a period during which new protein is synthesized. Puromycin added during this period prevents both the synthesis of this protein and the subsequent synthesis of DNA.

Synthesis of a spatial filter for the combined operations of subtraction and correlation

As is known, a coherent optical data processing system can be used to perform convolution and correlation with ease. Recently it has been shown that the system with diffraction gratings in the spatial filtering plane can also add or subtract complex patterns displayed symmetrically in the input plane. A method is described here for synthesizing a spatial filter so that the coherent system can perform both correlation and subtraction simultaneously in real time. As a particular application of this technique, we present results of using such filters in optical feature extraction.