Control Strips Research Articles

Lipoproteins in neonates

D E S P t T E T H E F A C T that hyperlipoproteinemia has received great clinical attention, there is a scarcity of information on the normal distribution of lipids and lipoproteins or screening tests for reliable detection of hyperlipoproteinemia in children. 1, 2 Kwiterovich and associates 3 and Glueck and associates 4 have suggested that hyperlipoproteinemia can be diagnosed at birth by elevated levels of umbilical cord cholesterol or low-density lipoprotein cholesterol. However, Darmady and associates 5 stated that serum cholesterol estimations in cord blood cannot be used as a screening test for the diagnosis of familial hypercholesterolemia because babies with elevated cholesterol had values distributed throughout the normal range when re-examined at one year of age. The purpose of the present study was to measure cord blood lipoproteins of healthy infants, and also to investigate if lipoprotein patterns might be useful in detecting hyperlipoproteinemia at birth. MATERIALS AND METHODS Lipoprotein agarose gel eleetrophoresis. The lipoprotein electrophoresis method of Noble 6 was carried out. The agarose gel strips were fixed, dried, and stained with Sudan Black B. The optical density of the dye solution was read in a spectrophotometer, and if the optical density react at 590 fell below 13, the solution was discarded. The Spinco Model RB analytrol provided densitometric scanning of stained electrophoretograms with automatic integration of the peaks of optical density. Variations in staining and technique were standardized against control strips containing known concentrations of human

Protection against induction of supersensitivity to catecholamines by cocaine.

1. Adrenaline, noradrenaline, isoprenaline, tyramine, phentolamine, pronethalol, histamine and acetylcholine were each tested for their ability to prevent cocaine from causing supersensitivity to catecholamines in cat spleen strips in vitro. A high concentration of one of these drugs was added to the bath 5 min before cocaine hydrochloride (10 mug/ml). The effect on subsequent responses to catecholamines was compared with the effect of cocaine in control strips in the absence of an interfering drug.2. Phentolamine completely abolished the potentiating effect of cocaine. Large doses of adrenaline or noradrenaline reduced, but did not completely prevent, potentiation. Tyramine, isoprenaline, pronethalol, histamine and acetylcholine did not prevent potentiation.3. The ability of these drugs to interfere with potentiation does not correlate well with their ability to interfere with uptake of noradrenaline. Interference with uptake by cocaine is therefore unlikely to account fully for potentiation.

PHOSPHOCREATINE AND NUCLEOTIDE CHANGES IN PIG LONGISSIMUS MUSCLE DURING THE DEVELOPMENT OF RIGOR MORTIS UNDER CONTROLLED ENVIRONMENTAL CONDITIONS

SUMMARYThis study was conducted to compare the depletion of phosphocreatine (PC) and nucleotides (ATP and ADP) in strips of muscle which had been used for extensibility meesurements in the rigorometer with control strips of muscle which had been held unrestrained in the same environment. There were no significant differences in PC and ATP between the rigorometer and control strips. Rigorometer strips from “Stress‐susceptible” pigs had less rapid and less extensive depletion of ADP than did control strips from the same animals. It appeared that extensibility remained in the tissue after the A TP had been depleted, but not after AOP reached a low level.

Effects of Antifouling Paints on Settling Larvae of the Bryozoan Bugula neritina L

The external anatomy, attachment, and metamorphosis of larvae of the bryozoan Bugula neritina L. are outlined briefly. Larvae placed in dishes of still water containing upward-facing, horizontal, copper antifouling and control paint surfaces aggregated on the former, but failed to attach and metamorphose properly. It is considered that this aggregation effect was initiated by copper ions progressively restricting the swimming movements of larvae passing over the antifouling paint surfaces, which would in time result in an accumulation of larvae in these particular sectors. Larvae no longer capable of swimming actively would gradually descend onto the antifouling paint, and would therefore be exposed to an increased concentration of copper ions. The attachment of larvae to vertical copper, mercury, and control paint strips in slowly moving seawater was compared. The numbers attaching to the control strips was 7 times greater than on the copper, and 20 times greater than on the mercury. The larvae attaching to the antifouling paints were moribund and easily dislodged. Observations made on larvae attempting to attach to vertical copper antifouling strips painted on the side of a shallow tray of still water showed no evidence of a repellent effect. Larvae remained at the antifouling surface until they eventually succumbed and descended to the tray floor in a moribund condition. The attachment of larvae to vertical surfaces of control and antifouling paints was compared in troughs of still water. About 90% of the larvae fell to the trough floor in a moribund condition after coming in contact with an antifouling paint; attachment to the latter was negligible. The effect was similar in all 24 antifouling paints tested. It is suggested that the terms "pre-attachment mortality" and "postattachment mortality" could be used to describe the effects observed in bryozoan and barnacle larvae respectively.

Part III. Constant Density Laboratory Process for Television Film

The requirements are outlined for a negative-positive laboratory process to obtain predictable waveforms at the output of a calibrated telecine camera chain for measured luminance of scene elements. By utilizing the inherent reproducibility of the photographic process, a constant density and density difference system may be established utilizing conventional processing and printing equipment and materials. Techniques are described for controlling the output of processing machines of the Houston Fearless type, particularly applicable to smaller laboratories associated with television broadcasting agencies. Statistical analysis of sensitometric control strips is employed to evaluate processing reproducibility. Chemical analysis of bromide content provides sufficient information to maintain image-forming conditions, when the replenishers for negative and positive developers have the same composition as the starting solutions (before the addition of bromide) and are added directly to processing machine tanks. Tolerances that may be readily achieved in the practical operation of a system of this type are given.

Comparative reactivities of aortic strips from hypertensive and normotensive rats to epinephrine and levarterenol.

Rats were rendered hypertensive by two different technics. Isometric tensions developed by strips of aorta from these rats, when exposed to various concentrations of epinephrine and levarterenol, were compared with those developed by aortic strips from normotensive controls. Almost all of the aortic strips from the DCA-salt hypertensive rats responded with smaller contraction tensions to both pressor agents than did the corresponding control strips from the normotensive animals. The same was true for most of the strips obtained from the renal hypertensive rats. These results do not lend support to the hypothesis that vascular hyperreactivity is the basis of many forms of hypertension.