Pharmacokinetic studies with benoxaprofen in man: prediction of steady-state levels from single-dose data

1 Plasma levels of benoxaprofen were measured in eight subjects 2-168 h after a single oral dose of 100 mg. Pharmacokinetic parameters were estimated by the NON-LIN computer programme using the two-compartment open model. Mean half-lives of absorption, distribution and elimination were respectively 0.4, 4.8 and 37.6 hours. Volumes of distribution were 6.8 and 3.2 litres for the central and peripheral compartments respectively. 2 Eleven subjects in groups of three or four were given 25 mg/day, 50 mg/day or 100 mg two times daily for 11 days. Their plasma levels were compared with those predicted from the above parameters, which were adjusted for individual body weights and elimination half-lives. Steady-state plasma levels were predicted in each case, and a resonable degree of accuracy (mean 91%) achieved. 3 There was no tendency for observed and predicted levels to diverge as the dose was increased, and there was no evidence of any change in the disposition of benoxaprofen on repeated dosing. 4 The pharmacokinetic parameters were used to predict steady state plasma levels for various dosage regimens.

Effects of withdrawal of a mitogenic stimulus on progression of fibroblasts into S phase: differences between serum and purified multiplication-stimulating activity

Multiplication-stimulating activity (MSA) for chicken embryo fibroblasts was purified from serum-free medium conditioned by the growth of a rat liver cell line. A comparison between calf serum and purified MSA was made regarding the regulation of the fibroblast cell cycle. Addition of serum or MSA to stationary, quiescent cells stimulates them to enter the DNA synthetic phase after a characteristic lag period. Exposure to serum for shorter periods of time will irreverisbly commit cells to continue through the cell cycle and initiate DNA replication in the absence of serum. In contrast, the withdrawal of purified MSA from the medium results in an abrupt halt in the progression of cells towards S phase. The results of labeled thymidine incorporation and autoradiographic experiments clearly indicate that the point at which cells become irreversibly committed to enter the DNA synthetic period is at or near the G1-S boundary. The abrupt decay of the stimulation upon withdrawal of purified MSA provides a unique opportunity to investigate the biochemistry of this discrete phase of the cell cycle.

Increased ouabain-sensitive 86Rubidium uptake after mitogenic stimulation of quiescent chicken embryo fibroblasts with purified multiplication-stimulating activity

Multiplication-stimulating activity (MSA), a protein which stimulates DNA synthesis and growth of chicken embryo fibroblasts, was purified from serum-free medium conditioned by the growth of a rat liver cell line. Purified MSA was shown to rapidly stimulate ouabain-sensitive Na+, K+-ATPase activity as measured by both enzyme assay and rate of 86Rubidium uptake. Labeled ouabain binding was also shown to increase after stimulation of quiescent cells by serum or purified MSA. Conditions which interfere with the ability of the cells to accumulate potassium, such as the presence of the specific inhibitor, ouabain; incubation in potassium-free medium; or the presence of the potassium ionophore, valinomycin, were all demonstrated to inhibit the stimulation of DNA synthesis by serum or purified MSA. These results suggest that an early event in the stimulation of DNA synthesis by purified MSA is an activation of membrane Na+, K+-ATPase with a resulting accumulation of potassium ions inside the cell.

Sensitivity and specificity of electrocardiographic diagnosis of ventricular motion disorders. Studies in patients recovered from myocardial infarction

Angiographic-electrocardiographic correlations were studied in 253 patients with coronary arterial disease. Left ventriculograms were examined for various motion disorders (local hypokinesia, akinesia, dyskinesia or aneurysm, and generalized hypokinesia). Electrocardiograms were reviewed for the presence of Q waves indicative of transmural myocardial infarction and for the presence of upward convex ST-segment elevation of at least 2 mm. Of 27 consecutively studied subjects with normal coronary arteries and normal ventriculograms, none had Q waves, giving a specificity of 100% for the Q wave. Pathologic Q waves (greater than or equal to 0.04 second) were found in 20% (19) of 96 patients with coronary arterial disease having normal ventricular motion, reducing the specificity for the Q wave to 80% in patients with documented coronary disease. Of 157 patients with coronary disease and ventricular dyssynergy, 118 had pathologic Q waves, yielding a sensitivity of 75%. Concomitant Q waves plus 2 mm ST-segment elevation were present in 45 of the 118 postinfarction patients with ventricular dyssynergy, giving a sensitivity of 38%. The specificity of this combination in coronary patients was 84%.

Transient inhibition of polyoma virus synthesis by sendai virus (parainfluenza I). II. Mechanism of the interference by inactivated virus

The mechanism of the transient inhibition of polyoma virus synthesis by betapropiolactone-inactivated Sendai virus was studied. Polyoma virus early functions did not appear to be affected, although deoxyribonucleic acid (DNA) and structural protein synthesis were inhibited 60 and 35% respectively. The inhibition of macromolecular synthesis was not sufficient to account for the 90% inhibition of infectious progeny formation. Encapsidation of polyoma DNA into mature virions appears to be completely inhibited after superinfection by beta-propiolactone-inactivated Sendai virus. Ultraviolet irradiation of live or beta-propiolactone-inactivated Sendai virus preparations abolishes the interfering capacity, indicating that a functional Sendai virus ribonucleic acid molecule is the interfering component.

Transient inhibition of polyoma virus synthesis by Sendai virus (parainfluenza I). I. Demonstration and nature of the inhibition by inactivated virus

Superinfection of polyoma virus-infected mouse embryo cells by beta-propiolactone-inactivated Sendai virus resulted in a 90% inhibition of the synthesis of infectious polyoma progeny. The interference is dependent upon the time of superinfection and the concentration of the inactivated virus. The inhibition of polyoma virus synthesis is transient in nature since normal synthesis of polyoma progeny virus is seen upon prolonged incubation. Interferon does not appear to be implicated in the interference. Various aspects of the biological and synthetic capabilities of beta-propiolactone-inactivated Sendai virus are also described.

Magnification and microminiature inspection

Experienced and naive subjects used a binocular microscope to inspect microminiature patterns (O's) containing occasional defective elements (C's). Detection of defective elements was significantly affected by the level of magnification. The performance curves indicate the existence of a level of magnification which will minimize time per correct inspection. This optimum point occurs when the visual angle subtended by the magnified defect is between 9.0 and 12.0 minutes of arc. Both illumination and pattern size affect the absolute level of inspector performance, but the optimum performance point with respect to magnification does not appear to be affected by either.

A fluorescent method for the detection and localization of zinc in human granulocytes

A new cytochemical method is presented for the fluorescent demonstration of zinc in human granulocytes using 8-hydroxyquinoline. This compound is known to form fluorescent complexes with magnesium, calcium and zinc. Specificity for zinc is accomplished by adjusting the staining solution to pH 8.0 with Michaelis universal buffer. The technique is simple, rapid and much more specific for zinc than the dithizone stain.

Cell division in Erwinia: inhibition of nuclear body division in filaments grown in penicillin or mitomycin C

Low concentrations of penicillin or mitomycin C in cultures of Erwinia sp. inhibit cell division. Electron-microscopic analysis of serial sections of these nondividing cells reveals that division of the nuclear body is also inhibited.

Cell division in a species of Erwinia. X. Morphology of the nuclear body in filaments produced by growth in the presence of D-serine

Filamentous cells of Erwinia sp. produced by growth in the presence of D-serine possess nuclear bodies that are not dividing normally. The nuclear bodies can be highly convoluted and continuous throughout large portions of the filaments. Possible reasons for failure of the nuclear body to periodically divide and suggested relationships to division of the cell are discussed.

Bacterial cell membranes. II. Possible structure of the basal membrane continuum of Micrococcus lysodeikticus

Treatment of isolated membranes from M. lysodeikitcus with acetone, ethanol, or methanol, but not ethyl acetate, extracts phospholipids and carotenoids. These extracted membranes are not disaggregated by such treatments and retain a three-layered appearance. The extracted membranes can be completely disaggregated by sodium lauryl sulfate, yielding subunits which are primarily protein (stripped subunits). These stripped subunits reaggregate into membranous sheets that also possess a three-layered structure. Conditions for reaggregation of stripped subunits are the same as for unstripped subunits. Extracted phospholipids and carotenoids from M. lysodeikitcus or phospholipids from Erwinia sp. are incorporated into the membranous sheets formed using the stripped subunits from M. lysodeikticus. The composition of the basal membrane continuum from M. lysodeikticus consists primarily of protein; most phospholipids and carotenoids appear to be present as superstructures on the top and bottom of the protein. Membrane protein is basic and does not appear to contain any cysteine. It is speculated that hydrophobic amino acids may be positioned in clusters on the facing sides of the molecules.

Bacterial cell membranes. I. Reaggregation of membrane subunits from Micrococcus lysodeikticus

The membranes from M. lysodeikticus can readily be disaggregated into a very small subunit form with sodium lauryl sulfate. Reaggregation of these subunits into membranous sheets occurs during dialysis in a menstruum of relatively low ionic strength, in the presence of a divalent cation at near neutral pH. Reducing conditions and a monovalent salt need not be present during dialysis. Effect of several compounds on membranes and subunit reaggregation was studied. Reaggregated membrane sheets are very similar chemically and morphologically to whole membranes; however, a difference was noted. The major bonding mode in membranes appears to involve hydrophobic groups.

Cell division in a species of Erwinia. IX. Electron microscopy of normally dividing cells

Grula, E. A. (Oklahoma State University, Stillwater), and Gerald L. Smith. Cell division in a species of Erwinia. IX. Electron microscopy of normally dividing cells. J. Bacteriol. 90:1054-1058. 1965.-Cells of an Erwinia species (an Enterobacteriaceae) divide by concomitant invagination of the cell wall and membrane. It is concluded that the process is initiated and sustained by the cell membrane.

Cell division in a species of Erwinia. 8. Amino acid composition of the mucopeptide in dividing and non-dividing cells

The Erwinia sp. studied possesses a discrete mucopeptide layer. This layer contains glutamic, diaminopimelic, and muramic acid, glucosamine, and alanine (1–1–1–1–2) as major components. Aspartic acid, glycine, and an unidentified ninhydrin-positive compound are also present but in lesser amounts. Content of glycine increases when cells are grown in a defined medium in the presence of glycine. Serine is present in the mucopeptide when cells are grown in the presence of D-serine, an inhibitor of cell division. Serine can partially replace glycine. Incorporation of serine is not significantly decreased by agents capable of preventing division inhibition by D-serine (pantoyl lactone or ammonium chloride). A new method for isolation of pure mucopeptide is presented.

THE DIAGNOSIS OF PREGNANCY WITH THE ASCHHEIM-ZONDEK TEST

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