Publications by authors named "Speck W"

Indigenous Art often expresses the complex culture of their creators and provides insight into the origins, histories, and values of that culture. Two examples of Northwest Indigenous Art suggest deeper meanings and the "power" of congenital anomalies.

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In this study, the systemic immune response to bacterial cell sonicates of Helicobacter pylori was characterized in children with symptomatic gastroduodenal disease. Isotype-specific antibodies to H. pylori in samples of serum from 16 children with culture-proven disease caused by H.

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There is now considerable evidence suggesting that C. pylori is a human pathogen. The strong association between C.

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The susceptibility of Campylobacter pylori was determined for the two topical anesthetic agents commonly used prior to gastroscopy. Campylobacter pylori proved to be extremely sensitive to the anti-infective activity of benzocaine, the active ingredient in most commonly used topical anesthetic agents, with minimum inhibitory concentrations of 0.14 mg/ml.

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During phototherapy for neonatal jaundice, bilirubin is converted into a variety of photoproducts. Determination of the relative importance of these photoproducts to the elimination of bilirubin requires knowledge of their rates of excretion. We have measured the rate at which the structural isomer of bilirubin, lumirubin, disappeared from the serum of nine jaundiced premature infants after the cessation of phototherapy.

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The results and data from the testing of 255 chemicals for mutagenicity in Salmonella are presented. All chemicals were tested under code using a preincubation modification of the Salmonella/microsome test in the absence of exogenous metabolic activation and in the presence of liver S-9 from Aroclor-induced male Sprague-Dawley rats and Syrian hamsters.

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37 aliphatic epoxides comprising 6 subclasses (unsubstituted aliphatic epoxides, halogenated aliphatic epoxides, glycidyl esters, glycidates, glycidyl ethers and diglycidyl ethers) were tested, under code, for mutagenicity in Salmonella strains TA98, TA100, TA1535 and TA1537 and/or TA97 with and without metabolic activation using a standardized protocol. The 4 halogenated aliphatic epoxides and the 4 diglycidyl ethers were all mutagenic. The 2 glycidates were negative in all strain/activation systems used while all 5 glycidyl esters were mutagenic.

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This publication includes data of Salmonella mutagenicity results on 270 coded chemicals, encompassing 329 tests performed by three laboratories under contract to the National Toxicology Program (NTP). The preincubation modification of the Salmonella/mammalian microsome assay was used to test chemicals in up to five Salmonella strains in the presence and absence of rat and hamster liver S-9. With a few exceptions, inter- and intralaboratory reproducibility was good.

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The purpose of our study was to compare the effects of narrow-spectrum blue light and broad-spectrum white light on the production of bilirubin photo-isomers in human infants with jaundice. Twelve preterm infants were studied under both white and blue light. Irradiance at 450 nm was controlled at 12 microW/cm2/nm for both light sources.

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Photoisomerization of native bilirubin to more polar configurational isomers (Z,E-bilirubin) and structural isomers (lumirubin) was studied in 20 premature infants with physiologic jaundice to determine the effect of low-dose (6 microW/cm2/nm) v high-dose (12 microW/cm2/nm) phototherapy. Patients were assigned prospectively to receive either low- or high-dose treatment. Study groups were comparable with regard to birth weight, gestational age, and total bilirubin prior to the initiation of phototherapy.

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Phototherapy results in the conversion of native bilirubin to more water-soluble configurational and structural isomers. The serum half-life for the configurational isomer, the principal photoproduct in vivo, was determined by high pressure liquid chromatography in six premature infants following cessation of phototherapy. The mean half-life for this isomer was 15 h.

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Lumirubin, a water-soluble photoproduct of bilirubin formed in vivo during phototherapy, is excreted in the urine. In premature infants with little or no bilirubin conjugating activity, lumirubin is the principal yellow pigment found in the urine during phototherapy. The clearance rate of lumirubin in nine premature infants varied from 0.

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Using four Salmonella typhimurium tester strains (TA1537, TA1538, TA98 and TA100) and the promutagen 2-aminoanthracene, an epidermal S9-mediated mutagenicity assay was developed. Using an activation mixture derived from whole skin of the rat, mutagenicity was observed in tester strain TA98 whereas an activation mixture derived from the dermis resulted in mutagenicity in tester strains TA1538, TA98 and TA100. Activation mixtures from both the epidermis and the liver produced a positive response in all of the tester strains studied.

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Di(2-ethylhexyl)phthalate and 33 other phthalates, ethylhexanol derivatives, and related chemicals were tested for mutagenicity in Salmonella typhimurium strains TA98, TA100, TA1535, and TA1537 without metabolic activation and in the presence of rat and hamster liver S-9 metabolic activation systems. No mutagenic activity was seen with any of the chemicals tested.

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Niridazole, a widely used antiprotozoan agent, is mutagenic for Salmonella typhimurium strains that contain guanine-cytosine as well as adenine-thymine base pairs at their mutational sites. The mutagenic activity for both types of targets depends upon nitroreduction.

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Components of the herbicide Agent Orange--2,4-dichlorophenoxyacetic acid (2,4,-D) and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) and their esters, and the contaminant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)--and related chemicals were tested for mutagenicity using Salmonella typhimurium strains TA98, TA100, TA1535, and TA1537. No mutagenic activity was observed for any of the chemicals tested.

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Phototherapy results in the conversion of bilirubin to more water-soluble isomers. Six clinically used phototherapy lamps which differ in their emission spectra have been compared in their ability to produce configurational and structural isomers of bilirubin in vitro. For all of the lamps, the initial rate of configurational isomerization was highly correlated (r = 0.

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Endocarditis and unilateral endophthalmitis due to Actinobacillus actinomycetemcomitans heart disease. The ocular infection was notable for its localized presentation and slow evolution. Treatment with systemic, subconjunctival, and topical gentamicin sulfate and ampicillin sodium achieved 20/20 acuity with a residual chorioretinal scar in the nasal periphery.

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Phototherapy results in transformation of bilirubin to more water-soluble isomers. The efficacy of monochromatic visible light from 350 to 550 nm in the fastest photoisomerization reaction was quantitated by high-pressure liquid chromatography. The most effective wavelengths in vitro (i.

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The minimal inhibitory concentrations (MICs) of 18 antibiotics including 16 beta-lactam antibiotics were determined by agar dilution on 70 strains of pneumococci (25 penicillin sensitive, 18 intermediate resistant and 27 resistant). The antimicrobials tested were penicillin G, ampicillin, carbenicillin, ticarcillin, piperacillin, mezlocillin, cephalothin, cefoxitin, cefamandole, latamoxef (moxalactam), cefotaxime, cefoperazone, ceftazidime, ceftriaxone, N-formimidoyl thienamycin, SCH 29482, chloramphenicol and vancomycin. Of these agents, only cefotaxime demonstrated greater activity than penicillin against intermediate penicillin-resistant strains while cefoperazone, ceftriaxone, N-formimidoyl thienamycin and vancomycin as well as cefotaxime demonstrated activity superior to penicillin against penicillin-resistant strains.

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The ability of standard phototherapy illumination to produce damage in intracellular DNA is well established. In this study, the addition of a dilute solution (1:6400) of a clinically-used multivitamin concentrate to human KB cells was found to enhance the generation of single-strand DNA breaks produced by broad-spectrum fluorescent light. The effect of the exogenous photosensitizing agent (multivitamins) was blocked by the enzyme catalase; thus, the photoproduct responsible for the DNA modification was hydrogen peroxide, an extremely reactive molecule capable of damaging a variety of biologic macromolecules.

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