Identification of Ly 5 on the surface of ‘natural killer’ cells in normal and athymic inbred mouse strains

This report that (1) cells mediating NK activity in different inbred mouse strains selectively express one of two allelic products specified by theLy-5 locus (or a locus tightly linked to it) and (2) this surface structure may directly contribute to NK-mediated cytolysis, since Ly 5 antiserum specifically inhibits NK activity in vitro in the absence of complement.     

Argon Laser Management of Cutaneous Vascular Deformities: A Preliminary Report

Twenty-two patients with cutaneous vascular malformations were treated with an argon laser. Promising results were obtained in patients with port-wine stains, hemangiomas, telangiectasia and varicose veins. The argon laser shows promise as an effective clinical tool in the treatment of all such cutaneous vascular abnormalities. However, further study of clinical as well as laboratory data is necessary over a long period of time before this modality can be definitely recommended as the treatment of choice for vascular deformities of the skin.     

Recovery of Yersinia enterocolitica from streams and lakes of California.

Stream and lake water from the Mammoth Lakes region of California was sampled for Yersinia enterocolitica. From 10 of the 34 sites examined, organisms were isolated that were biochemically identified as Y. enterocolitica. Only one of the ten strains could be serologically confirmed. This strain was identified as Y. enterocolitica serotype 16. Although an outbreak of enteritis in the area prompted this study, no correlation with gastrointestinal disease could be established since the majority of the strains were untypeable.     

Fluorescence studies of 1,N6-ethenoadenosine triphosphate bound to G-actin: the nucleotide base is inaccessible to water

When 1,N6-ethenoadenosine triphosphate (epsilon-ATP) is free in solution, its fluorescence is collisionally quenched by iodide ion, by methionine, by tryptophan, and by cysteine. None of these quenches the fluorescence of epsilon-ATP bound to G-actin. Thus, the ethenoadenine base is bound in a region of the protein which is inaccessible to collisions with these reagents. Since we have previously shown that the fluorescence of epsilon-ATP is quenched by water, the long lifetime of epsilon-ATP bound to G-actin (36 nsec, vs 27 nsec for epsilon-ATP in water) indicates that the bound nucleotide base is inaccessible to collisional quenching by water molecules.     

Follow-up study of small-for-dates babies.

A group of small-for-dates full-term babies whose intra-uterine growth was followed by serial ultrasonic cephalometry were examined at a mean age of 4 years. Those children whose skull growth had begun to slow in utero before 34 weeks'' menstrual age were more likely to have a height and weight less than the 10th centile. When the onset of growth failure had occurred before 26 weeks there was a lower developmental quotient at follow-up using the Griffiths extended scales. Prolonged slow growth in utero therefore seems to be followed by slow growth and development after birth.     

Pentobarbital anesthesia: Lack of effect on venous prostaglandins in dogs

Venous prostaglandins A, E, and F were determined by radioimmunoassay in 10 dogs before and one hour after administration of sodium pentobarbital (35 mg/Kg, iv). In the conscious state, PGA was 0.34 ± 0.04 ng/ml (mean ± SE), PGE 0.20 ± 0.01 ng/ml, and PGF 0.25 ± 0.03 ng/ml. During pentobarbital anesthesia, these levels were unchanged (p >0.05). Thus, pentobarbital anesthesia had no effect on peripheral venous prostaglandin levels.     

Affinity chromatography on immobilised nucleotides. Some applications to the purification of thermophilic dehydrogenases and kinases.

The effect of pH and temperature on the capacity and binding of Bacillus stearothermophilus, alcohol dehydrogenase and phosphofructokinase to N6-(6-aminohexyl)-5'-AMP-Sepharose has been examined. Specific elution from the substituted AMP-Sepharose was examined using a variety of cofactors, fragments of cofactors and substrates. A purification scheme for each enzyme on the substituted AMP-Sepharose using nucleotides and gradients of pH and salt is presented. Interestingly, elevated temperature increased the affinity of both enzymes for N6-(6-aminohexyl)-5'-AMP-Sepharose, however, the Michaelis constant for nucleotide determined at various temperatures remained constant. The effect of pH and salt concentration on the binding of B. stearothermophilus glyceraldehyde-3-phosphate dehydrogenase to 6-aminohexanoyl-NAD+-Sepharose was also examined; raising the pH above 7.5 lowers the capacity of the matrix and the effect of a range of ammonium sulphate concentrations on the adsorption of the enzyme was examined. A specific purification of glyceraldehyde-3-phosphate dehydrogenase from partially purified extracts of this organism was achieved.     

A stochastic model for facilitated transport of oxygen through tissue slices

Longmuir and co-workers have reported that respiration of certain tissue slices is approximated by Michaelis-Menten kinetics. From this and other experimental findings, Longmuir proposed that a carrier is involved in tissue oxygen transport. Gold developed a deterministic model to examine this hypothesis. This report presents a stochastic model for a fixed site carrier in a more general framework that includes the stochastic counter-part to Gold's deterministic model as a special case. The kinetics of tissue oxygen consumption predicted by the model are examined for various cases.     

Determination of the 3'' terminal nucleotide of DNA fragments

A new method for determining the 3'-terminal nucleotide of a DNA strand is presented. Use is made of the fact that one (and only one) 2',3'-dideoxyribonucleotide can be added to the 3'-end of a DNA fragment with calf thymus terminal transferase. Addition of more than one nucleotide analog per strand is impossible due to the absence of a 3'-terminal hydroxyl group. If the terminatind dideoxyribonucleotide contains an (alpha 32p) label, the resulting 3'-blocked strand can be digested by "nearest neighbor" techniques and the original 3'-endgroup determined. Picomole quantities of DNA strands can be labeled and the 3'-end determined.