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Biomedical subjects

R Wayne

Publications and source records attributed to R Wayne.

At least 37 records · Page 2Linked to original sources
PubMed1989

Rural trauma management.

Rural trauma is a major problem in the United States. Up to 70 percent of trauma fatalities occur in rural areas, even though 70 percent of the population live in urban areas. Over the past 3 decades, numerous studies have defined the concept of preventable trauma death in both rural and urban populations. With the development of a regional trauma care system in Oregon, preventable trauma mortality should decrease. An effort was made to improve the quality of trauma care in Clatsop County, Oregon, a community of 30,000 people with 2 small rural hospitals. To obtain this goal, four steps were taken: (1) physician and nurse education was improved, (2) trauma protocols promoting prompt resuscitation and stabilization of patients were established, (3) regular trauma case reviews were conducted, and (4) emergency medical technician and prehospital management were coordinated. This study reviews the trail from sporadic, uncoordinated rural trauma care to the designation process.

Adolescent↗
PubMed1989

Calcium requirement of phytochrome-mediated fern-spore germination: no direct phytochrome-calcium interaction in the phytochrome-initiated transduction chain.

Phytochrome-mediated germination of fern spores of Dryopteris paleacea Sw. was initiated by a saturating red-light (R) irradiation after 20 h of imbibition. For its realization external Ca2+ was required, with a threshold at a submicromolar concentration, and an optimum was reached around 10(-4) M. At concentrations > or = 10(-1) M only a reduced response was obtained, based probably on an unspecific osmotic or ionic effect. The germination response was inhibited by La3+, an antagonist of Ca2+. From these results it is concluded that Ca2+ influx from the medium into the spores may be an important event in phytochrome-mediated germination. In the absence of Ca2+ the R-stimulated system remained capable of responding to Ca2+, added as late as 40 h after R. Moreover, Ca2+ was effective even if added after the active form of phytochrome, Pfr, had been abolished by far-red (FR) 24 h after R. Thus, the primary effect of Pfr, that initiates the transduction chain, does not require calcium. "Coupling" of Pfr to subsequent dark reactions has been investigated by R-FR irradiations with various dark intervals. The resulting "escape kinetics" were characterized by a lag phase (6 h) and half-maximal escape from FR reversibility (19 h). These kinetics were not significantly changed by the presence or absence of calcium. Thus, direct interaction of Pfr and calcium is not a step in the transduction chain initiated by the active form of phytochrome.

Calcium↗
PubMed1988

Early quantitative method for measuring germination in non-green spores of Dryopteris paleacea using an epifluorescence-microscope technique.

A method is described to determine germination by blue-light excited red fluorescence in the positively photoblastic spores of Dryopteris paleacea Sw. This fluorescence is due to chlorophyll as evidenced from 1) a fluorescence-emission spectrum in vivo, where a bright fluorescence around 675 nm is obtained only in red light (R)-irradiated spores and 2) in vitro measurements with acetone extracts prepared from homogenized spores. Significant amounts of chlorophyll can be found only in R-treated spores; this chlorophyll exhibits an emission band around 668 nm, when irradiated with 430 nm light at 21 degrees C. Compared to other criteria for germination, such as swelling of the cell, coat splitting, greening, and rhizoid formation, which require longer periods after induction for their expression, chlorophyll fluorescence can be used to quantify germination after two days. This result is confirmed by fluence-response curves for R-induced spore germination; the same relationship between applied R and germination is obtained by the evaluation with the epifluorescence method 2 days after the light treatment as compared with the evaluation with bright-field microscopy 5 days after the inducing R. Using this technique we show for the first time that Ca2+ contributes to the signal-transduction chain in phytochrome-mediated chlorophyll synthesis in spores of Dryopteris paleacea.

Calcium↗
PubMed1986

Radial keratotomy and glare effects on contrast sensitivity.

After radial keratotomy (RK) to correct myopia, some patients complain of 'glare'. Effects of a glare source on contrast sensitivity were measured in fifteen patients after unilateral RK. With each eye, determinations were made of the contrast required for detection of steady gratings (spatial frequencies of 0.7 and 2.9 cycles/deg), and for detection of flicker (unpatterned field flickering at rates of 8, 16, and 32 Hz). Grating or flicker was presented on a centrally fixated 4 deg test target (34 cd/m2 mean luminance), surrounded by a diffuse glare source (1700 cd/m2 mean luminance). For each stimulus, contrast thresholds were determined with glare-source off and with glare-source on. 'Glare loss' was defined as the decrement in contrast sensitivity measured with the glare source on. Significant findings were: (1) Both eyes showed glare losses for detection of gratings and for detection of flicker; (2) Spectacle lenses increased glare losses both for gratings and for flicker; (3) The RK eye showed a larger glare loss for flicker than the unoperated eye, but a smaller glare-loss for gratings; (4) For both flicker and gratings, glare loss tended to be greater in the RK eye, compared to the unoperated eye, in subjects who had larger pupil diameters in the testing situation; (5) The psychophysical measurements obtained in this study were not significantly correlated either with a questionnaire index of glare complaints or with the score obtained with the Miller-Nadler GlareTester.

Adult↗
PubMed1985

Red Light Stimulates an Increase in Intracellular Calcium in the Spores of Onoclea sensibilis.

Red light (R) stimulates an increase in the total concentration of intracellular calcium in the spores of Onoclea sensibilis L. as determined by atomic absorption spectroscopy. Subsequent exposure to far-red light inhibits the R-induced increase in intracellular calcium. The majority of the increase occurs 5 minutes after the onset of irradiation. The calcium antagonist, La(3+), inhibits both germination and the R-induced increase in intracellular calcium. The R-induced increase in calcium is sufficient to account for an increase in the concentration of intracellular calcium ions from 0.1 micromolar to 1 to 10 micromolar. Large detectable changes in other elements tested are not required for germination.

Journal Article↗
PubMed1984

Foreign body reactions secondary to cellulose lint fibers.

Twenty-four cases of foreign body reactions secondary to cellulose lint fibers have been identified in three Portland area hospitals over a 5 year period. Ten of these cases involved extraperitoneal granuloma and 14 cases intraperitoneal granuloma. Six of the intraperitoneal reactions resulted in acute granulomatous peritonitis, and one of these patients died from this complication. Twenty-two additional operations were performed on these patients because of complications directly associated with this reaction. As estimated 400 days of additional hospitalization were required secondary to complications of foreign body reaction. Several precautionary measures have been identified that have decreased the incidence of this complication in our hospitals. Polypropylene drapes and gowns may provide a solution to this problem in the future.

Acute Disease↗
PubMed1984

Gastrointestinal symptoms of marathon runners.

A survey of 707 participants in the 13th Annual Trail's End Marathon in Seaside, Oregon, showed a high incidence of gastrointestinal disturbances, predominantly of the lower tract, associated with long-distance running. The urge to defecate, both during and immediately after running, occurred in over a third of runners. Bowel movements (35%) and diarrhea (19%) were relatively common after running, and runners occasionally interrupted hard runs or races for bowel movements (18%) or diarrhea (10%). Lower gastrointestinal disturbances were more frequent in women than in men and in younger than in older runners. Awareness of the frequency and nature of gastrointestinal symptoms documented by this survey will assist physicians in evaluating abdominal complaints in runners.

Adolescent↗
PubMed1981

Simultaneous amebic liver abscess and hepatitis A.

A child with amebic colitis, liver abscess and hepatitis A is reported. Speculation as to why these two infectious agents have rarely been associated is presented. Diagnosis of hepatitis was not suspected in this case until physicians caring for the patient developed clinical hepatitis. The importance of suspecting hepatitis A in all patients with unexplained liver enzyme elevations is stressed.

Female↗
PubMed1981

The effect of vasopressin on gastric wound healing.

The gastric incisions of rabbits intra-arterially infused with vasopressin were analyzed for collagen synthesis, tensile strength and inflammatory reaction for five, ten and 20 days from the time of wounding. Significant differences were looked for in the collagen content of treated and untreated wounds. Tensile strength of a strip of gastric wound with sutures removed was tested on a motor driven tensiometer. The breaking point of the strip in grams of weight required was used as the end point. A portion of tissue from the wound site of each of the 36 rabbits was processed for microscopic examination, and the resulting slides were labeled with code numbers to preserve blind conditions. The effect of vasopressin on the healing of a standard gastric incision in the rabbit was studied. When compared with those rabbits in the control study which were infused with a saline solution alone, no significant difference was found in tensile strength, inflammatory response or synthesis of new collagen, as determined by the hydroxyproline ratio. There would appear to be no adverse effects upon gastric wound healing as a result of intra-arterially infused vasopressin in the concentrations used in this experiment.

Animals↗
PubMed1981

Hospital-acquired hepatitis a: report of an outbreak.

A nosocomial outbreak of hepatitis A occurred after hospitalization of a 21-month-old girl with amebic liver abscess and unsuspected, anicteric hepatitis A. The index patient, who had an acute diarrheal illness prior to enzyme elevations, seroconverted from IgM hepatitis A antibody to IgG hepatitis A antibody. Of the 103 hospital personnel with known or potential exposure, three physicians (2.9%) contracted clinical hepatitis A, 27 to 29 days after their initial contact with the source patient. A fourth physician developed subclinical infection. Two of the three clinical cases occurred in two of the three primary care physicians of the source patient. Hepatitis A should be considered in any patient with acute, unexplained liver enzyme abnormalities. Diarrhea occurring in a fecally incontinent child incubating hepatitis A may increase the risk of transmission.

Acute Disease↗
PubMed1976

Operative cholangiography in uncomplicated biliary tract surgery. Review of 354 cholangiography studies in patients without indication of common duct pathology.

The literature of the past ten years is replete with articles on "routine* cholangiography, with particular reference to the overlooked or "unsuspected" stone. Many series do not differentiate between T-tube cholangiograms performed after common duct exploration and those performed on patients with and without the usual clinical or operative indications for common duct exploration. We present a pure operative cholangiographic study of 354 patients with apparent uncomplicated bilary tract disease; a significant incidence of unsuspected pathologic features are demonstrated. Can a convenient and innocuous procedure like routine operative cholangiography continue to be ignored, even in the most routine of cases?

Adenoma, Bile Duct↗
PubMed1976

Siderophore protection against colicins M, B, V, and Ia in Escherichia coli.

A variety of natural and synthetic siderophores capable of supporting the growth of Escherichia coli K-12 on iron-limited media also protect strain RW193+ (tonA+ ent-) from the killing action of colicins B, V, and Ia. Protective activity falls into two categories. The first, characteristic of enterobactin protection against colicin B and ferrichrome protection against colicin M, has properties of a specific receptor competition between the siderophore and the colicin. Thus, enterobactin specifically protects against colicin B in fes- mutants (able to accumulate but unable to utilize enterobactin) as predicted by our proposal that the colicin B receptor functions in the specific binding for uptake of enterobactin (Wayne and Neilands, 1975). Similarly ferrichrome specifically protects against colicin M in SidA mutants (defective in hydroxamate siderophore utilization). The second category of protective response, characteristic of the more general siderophore inhibition of colicins B, V, and Ia, requires the availability or metabolism of siderophore iron. Thus, enterobactin protects against colicins V and Ia, but only when the colicin indicator strain is fes+, and hydroxamate siderophores inhibit colicins B, V, and Ia, but only when the colicin indicator strain is SidA+. Moreover, ferrichrome inhibits colicins B, V, and Ia, yet chromium (III) deferriferrichrome is inactive, and ferrichrome itself does not prevent adsorption of colicin Ia receptor material in vitro. Although the nonspecific protection against colicins B, V, and Ia requires iron, the availability of siderophore iron for cell growth is not sufficient to bring about protection. None of the siderophores tested protect cells against the killing action of colicin E1 or K, or against the energy poisons azide, 2, 4-dinitrophenol, and carbonylcyanide m-chlorophenylhydrazone. We suggest that nonspecific siderophore protection against colicins B, V, and Ia may be due either to an induction of membrane alterations in response to siderophore iron metabolism or to a direct interference by siderophore iron with some unknown step in colicin action subsequent to adsorption.

Azides↗
PubMed1976

Effect of norepinephrine on gastric wound healing.

Lavage of the stomach with norepinephrine has been suggested as a temporary means of controlling upper gastrointestinal tract bleeding. The effect of norepinephrine on the healing of a standard gastric incision in the rat was studied using irrigation topically. When compared with those rats in the control study that were irrigated with a saline solution alone, no significant difference was found in the tensile strength, local inflammatory response or synthesis of new collagen, as determined by the hydroxyproline-proline ratio. There would appear to be no adverse effect on gastric wound healing as a result of preliminary irrigation of the gastric mucosa with norepinephrine given topically in a concentration of 16 milligrams per liter.

Animals↗
PubMed1975

Evidence for common binding sites for ferrichrome compounds and bacteriophage phi 80 in the cell envelope of Escherichia coli.

Mutants ton A and ton B of Escherichia coli K12, known to be resistant to bacteriophage phi80, were found to be insensitive as well to albomycin, an analogue of the specific siderochrome ferrichrome. Ferrichrome at micromolar concentrations strongly inhibited plaque production by phi80. Preincubation with ferrichrome did not inactivate the phage. At a concentration at which ferrichrome allowed 90% inhibition of plaque formation, the chromium analogue of ferrichrome showed no detectable activity. Similarly, ethylenediaminetetraacetic acid, ferrichrome A, and certain siderochromes structurally distinct from ferrichrome, such as ferrioxamine B, schizokinen, citrate, and enterobactin, did not show detectable inhibitory activity. However, rhodotorulic acid showed moderate activity. A host range mutant of phi80, phi80h, was also inhibited by ferrichrome, as was a hybrid of phage lambda possessing the host range of phi80. However, phage lambdacI- and a hybrid of phi80 possessing the host range of lambda were not affected by ferrichrome. Finally, ferrichrome and chromic deferriferrichrome were shown to inhibit adsorption of phi80 to sensitive cells, ferrichrome giving 50% inhibition of adsorption at a minimal concentration of 8 nM. It is suggested that a component of the ferrichrome uptake system may reside in the outer membrane of E. coli K12 and may also function as a component of the receptor site for bacteriophage phi80, and that ferrichrome inhibition of the phage represents a competition for this common site.

Adsorption↗
PubMed1975

Parathyroid cysts: Functional and mediastinal.

A report of a functioning mediastinal parathyroid cyst is presented with a review of the world literature. This represents the tenth functional, eleventh mediastinal, and third functioning mediastinal parathyroid cyst reported. The predilection of functional cysts for aberrant locations would suggest on hypothesis of their occurrence by degeneration of pre-existing adenomas based on an inadequacy of their blood supply. The criteria for ascribing functional activity to a parathyroid cyst are presented and discussed.

Adult↗