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Biomedical subjects

R White

Publications and source records attributed to R White.

At least 739 records · Page 41Linked to original sources
PubMed1977

Elastase secretion by peritoneal exudative and alveolar macrophages.

Mouse alveolar macrophages (AM) cultured in the absence of serum secrete an elastolytic enzyme. The elastase from AM resembles the previously described elastase from peritoneal macrophages (PM) in pH optimum and inhibition profile. The macrophage enzymes do not appear to be stored, and with periodic changes in the culture medium, accumulate extracellularly for up to 10 days. Resident PM produce barely detectable levels of extracellular elastase unless given a phagocytic load. Thioglycollate-stimulated peritoneal exudative macrophages (PEM), however, secret easily detectable levels of elastase, which can be further increased with a phagocytic load. Without any additional stimulation, AM secret an elastolytic activity comparable to that of the PEM receiving a phagocytic load, but unlike PM they do not increase elastase secretion after phagocytosis.

Animals↗
PubMed1977

Venous gas bubbles: production by transient, deep isobaric counterdiffusion of helium against nitrogen.

When awake goats were subjected to isobaric gas switching from saturation (17 hours) on 4.7 atmospheres of nitrogen (0.3 atmosphere of oxygen) to 4.7 atmospheres of helium (0.3 atmosphere of oxygen), bubbles detected by 5-megahertz Doppler ultrasound in the posterior vena cava 20 to 60 minutes after the switch continued for 4 hours. Similar experiments carried out at 6.7 atmospheres of inert gas and 0.3 atmosphere of oxygen produced more bubbles for as long as 12 hours after the gas switch. This is believed to be the first objective demonstration of the phenomenon of deep isobaric supersaturation under transient operational diving conditions at relatively shallow diving depths. Detection of bubbles by Doppler ultrasound confirms the potential importance of the phenomenon to shallow saturation diving and holds promise for better quantitification of its effects as well as those of its counterpart, isobaric undersaturation, which can confer a decompression advantage.

Animals↗
PubMed1977

Trad or trend?

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Financing, Organized↗
PubMed1977

Hit or miss?

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Delivery of Health Care↗
PubMed1977

Characteristics of tyrosinase in B16 melanoma.

Tyrosine hydroxylase, dopa oxidase, and peroxidase activities were studied in soluble fractions of B16 melanoma tumor homogenates by polyacrylamide gel disc electrophoresis. Stained gels were scanned photometrically and gel slices were assayed radiometrically. In these preparations, the two bands of tyrosine hydroxylating activity were completely separated from the peroxidase activity but coincided with two major bands of dopa oxidase activity. The third dopa oxidase band coincided with the single band of peroxidase activity. The soluble fraction of cultured cell homogenates had no peroxidase activity, but the two tyrosine hydroxylase bands coincided exactly with the two dopa oxidase bands. Therefore, in the soluble fraction of the murine melanoma bifunctional tyrosinase does exist as two electrophoretically separable forms which are independent of peroxidase.

Animals↗
PubMed1977

Artificial insemination.

Artificial insemination with homologous (AIH) and heterologous (AID) samples is discussed. Specific emphasis is placed on the indications and timing of the procedure, the type of specimens available, the technique and the expected results. The legal and emotional ramifications of AID are discussed.

Clomiphene↗
PubMed1976

Resources.

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Nurses↗