Industrial exposure to hydrogen cyanide: implications for treatment.
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Humans↗
Biomedical subjects
J M Anderson
Publications and source records attributed to J M Anderson.
Emergency medical kits to be required cargo on commercial airliners. But will they fill the bill?
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Aviation↗
The separation of o-phthalaldehyde derivatives of amino acids by reversed-phase chromatography on octylsilica columns.
Amino acids were reacted with o-phthalaldehyde and 2-mercaptoethanol and were separated using a simple linear gradient from 10 to 65% methanol over 15 min on an octyl silica (C8) column by reversed-phase chromatography. The separation obtained was found to be sensitive to the pH, ionic strength, and tetrahydrofuran concentration of aqueous solvent A [THF: sodium acetate (45 mM), pH 5.7, (4:96)]. These effects were characterized and used to design a rapid (17 min) separation of the amino acids commonly found in acid hydrolysates of proteins. A more involved procedure was used to separate the more complex mixture of amino acids that are found in enzymatic hydrolysates of proteins or in physiological fluids. The simplicity of the methods allows their use on different chromatographic systems with little or no alteration.
Amino Acids↗
In vivo biocompatibility studies. VII. Inflammatory response to polyethylene and to a cytotoxic polyvinylchloride.
The cellular biocompatibility of low-density polyethylene and a cytotoxic polyvinylchloride were investigated using an in vivo cage implant system. Components of the inflammatory response (white cells, extra-cellular alkaline and acid phosphatase, the complement component C3, and total protein content) were monitored over a 21-day implantation period. Scanning electron microscopy was used to evaluate the morphologic condition of leukocytes adherent to the implanted polymers. Prior to implantation, each polymer was evaluated using an established primary acute toxicity screen. The results showed that the cytotoxic polyvinylchloride stimulated an intense acute phase inflammatory response, and at later observation periods, an intense and increasing chronic inflammatory response. In contrast, the polyethylene promoted relatively small increases in the acute and chronic phases of inflammation; the overall cellular response being essentially resolved by the third week after implantation. The initial toxicity screen of each polymer suggested that the observed differences in inflammation were primarily caused by the release from the polyvinylchloride of the added cytotoxic agent (dioctyltinbisoctylmercaptoacetate).
Acid Phosphatase↗
The effects of an enhanced inflammatory reaction on the surface properties of cast Biomer.
The ability of a biomaterial to withstand the rigors of the harsh biologic environment is an important consideration when considering a material for long-term biomedical applications. Using a cage implant system, the effects of an intense inflammatory reaction on cast Biomer have been investigated. The inflammatory response to cast Biomer was greatly increased by coimplanting Biomer films with a cytotoxic poly(vinyl chloride) (PVC) in rats for a period of 21 days. Cast Biomer films were characterized by weight, advancing contact angle with water in air, attenuated total reflectance infrared spectroscopy and scanning electron microscopy (SEM). The analyses were performed before any treatment, after autoclaving and sonication, and after 21 days implantation with the cytotoxic (PVC) in rats. The results of the study indicated that cast Biomer does not undergo significant chemical degradation when subjected to the effects of an intense inflammatory reaction for 21 days. Implantation does, however, lead to rearrangement that results in a more polar and hydrophilic surface, suggesting that the polymer adapts to the hydrophilic environment of the inflammatory exudate.
Animals↗
Fluorescent hydrazides for the high-performance liquid chromatographic determination of biological carbonyls.
Methods for the determination of carbonyl compounds of biological origin by high-performance liquid chromatography were improved by the use of new fluorescent derivatizing agents. Eight fluorescent hydrazides were either synthesized or obtained commercially and compared to dansyl hydrazine (1-dimethylaminonaphthalene-5-sulfonylohydrazide). Four of the compounds yielded carbonyl hydrazones with a higher relative fluorescence quantum yield than dansyl hydrazine in acetonitrile:water mixtures. Darpsyl hydrazide [(3-phenylpyrazoline-1-yl)-4-phenylsulfonylohydrazide] and apmayl hydrazide [N-(2-aminophenyl-6-methylbenzthiazole)-acetylohydrazide] both yielded an increase of greater than 20-fold in sensitivity over dansyl hydrazine in determinations of abscisic acid and jasmonic acid from plant tissues. Different hydrazides and derivatizing conditions were found to be optimum for the determination of different carbonyl compounds. Also, a simple method for precolumn purification of the hydrazones of acidic carbonyls was developed to remove contaminants arising during derivatization and from the tissue source.
Abscisic Acid↗
The platelet reactivity of vascular graft prostheses: an in vitro model to test the effect of preclotting.
An in vitro perfusion system was used to study the platelet reactivity of the following vascular graft materials when tested with human blood: expanded polytetrafluoroethylene (ePTFE), crimped Dacron Bionit (DB) and preclotted Dacron Bionit (DB/PC). These materials were simultaneously compared to silicone rubber (SR) using an identical perfusion circuit with the same donor's blood. All vascular graft materials tested in this in vitro perfusion system caused some degree of platelet activation as shown by a decrease in platelet count, an increase in platelet factor 3 activity, elevation of plasma levels of both platelet factor 4 and beta-thromboglobulin and decreased platelet aggregability. The observed platelet activation was striking for Dacron and especially preclotted Dacron, with ePTFE showing low levels of platelet activation. Platelet activation by Dacron was initially rapid and then levelled off, whereas the platelet activation with preclotted Dacron began more slowly, but reached much greater levels after three hours of in vitro perfusion.
Blood Coagulation↗
Surface modification of soft contact lenses: silanization, wettability and lysozyme adsorption studies.
The surface reactions of poly(2-hydroxyethylmethacrylate) (PHEMA) and the copolymer poly(HEMA-methacrylic acid) (PHEMA/MAA) with methyltrimethoxysilane, ethyltrimethoxysilane and phenyltrimethoxysilane have been characterized by attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy. A model compound, hydroxyethyl isobutyrate was synthesized and subsequently reacted with phenyltrimethoxysilane. Its FTIR spectrum was compared with the ATR-FTIR spectra mentioned above. Protein adsorption experiments showed that silanized PHEMA/MAA soft contact lenses adsorbed less lysozyme than the untreated lenses.
Adsorption↗
Characterization of protein adsorption on soft contact lenses. IV. Comparison of in vivo spoilage with the in vitro adsorption of tear proteins.
Tear protein and gamma-globulin mixtures were adsorbed on soft contact lenses of different chemical composition, surface quality and water content. The adsorption process was followed by Fourier transform infrared-attenuated total reflectance spectroscopy (ATR-FTIR). It was found that gamma-globulin underwent a conformational and orientational change after its adsorption and the extent of structural change appeared to be proportional to the binding strength of the protein with the hydrogel surface. Electrostatic interactions play a major role in the protein adsorption on lenses containing methacrylic acid. Lysozyme is selectively adsorbed on all of the high water content hydrogels and mucin is the major protein component for the pure PHEMA type of lenses. Studies on in vivo spoiled PHEMA and PVP/MMA lenses indicate that lysozyme is the major adsorbed deposit. Papain cleaning of in vivo spoiled lenses shows that although a portion of the deposits is desorbed, the enzyme itself becomes irreversibly adsorbed to the contact lens which may cause harmful effects to the eye.
Adsorption↗
Protein adsorption on soft contact lenses. III. Mucin.
Adsorption of bovine submaxillary mucin (BSM) on three different soft contact surfaces, lathe cut (LC) and spin cast (SC) crosslinked poly-2-hydroxyethylmethacrylate and spin cast poly(2-hydroxyethylmethacrylate/methacrylic acid) (PHEMA/MAA), was studied. The in vitro process was followed by attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR). A three-layer structure is envisaged for the adsorbed BSM: a very thin surface layer of strongly bound and conformationally altered mucin constitutes the surface layer. A random to beta-sheet structural transition activated by the hydrogel surface is proposed for this layer. Glycoprotein hydrogen-bonding with the polymer hydroxyls and interaction of charged and hydrophobic groups with hydrogel surfaces are important in stabilizing this layer. Most of the adsorbed BSM (99%) is found in the middle and top layers which are formed by a different degree of associated BSM (their conformation is minimally changed or not changed at all, respectively) and are weakly adsorbed to the lens surfaces. Surface morphology and chemical composition of the lenses are important adsorption parameters only for the reversibly adsorbed BSM.
Adsorption↗
Increased efficacy in selective elimination of leukemic cell line clonogenic cells by a combination of monoclonal antibodies BA-1, BA-2, BA-3 + complement and mafosfamid (ASTA Z 7557).
Studies were undertaken to examine the efficacy of combining monoclonal antibodies BA-1, BA-2, BA-3 + complement with a stabilized derivative of cyclophosphamide (mafosfamid) for elimination of leukemic cell line clonogenic cells. In a series of experiments conducted with leukemic cell lines a combination of two cycles of treatment with BA-1, 2, 3 + complement combined with 25 micrograms/ml-1 mafosfamid was superior to either modality alone in killing clonogenic leukemic cells. Identical treatment of normal bone marrow had no effect on the monopotent stem cells CFU-E and CFU-GM, or the pluripotent stem cell CFU-MIX, but some inhibition of the monopotent stem cell CFU-MK did occur. These results suggest that consideration be given to incorporation of BA-1, 2, 3 + complement and mafosfamid combination treatment in autologous bone marrow transplantation for acute lymphoblastic leukemia.
Antibodies, Monoclonal↗
Ethnicity and illness experience: ideological structures and the health care delivery system.
This paper analyses the experiences of Anglo-Canadian and immigrant Chinese families with a chronically ill child by using the idea that the social organization and ideology of health care services generate particular illness experiences. Immigrant families find the ideology dissonant with their customs for managing illness. The disjuncture between practices often leads to non-compliance and ineffective treatment. Health professionals explain non-compliance by the obvious facts of cultural differences, but I argue that it should be understood by institutional practices that exclude families from participating in caretaking. I maintain that patients and families should be included in decisions that affect their lives. Pressures from government to economize by increasing home care services, and the increasing number of immigrants may force practitioners to negotiate culturally acceptable care with them.
Canada↗
Differences in actin localization during bud and hypha formation in the yeast Candida albicans.
Stationary phase cells of Candida albicans can form either a bud or a hypha, depending upon the pH of the medium into which they are released. At low pH, cells form an ellipsoidal bud and at high pH, cells form an elongated hypha. By staining cells with rhodamine-conjugated phalloidin, we have compared the dynamics of actin localization during the formation of buds and hyphae. Before evagination, actin granules were distributed throughout the cytoplasmic cortex in both budding and hypha-forming cells. Just before evagination, actin granules clustered at the site of evagination, then filled the early evagination in both budding and hypha-forming cells. With continued bud growth, the actin granules then redistributed throughout the cytoplasmic cortex. In marked contrast, with continued hyphal growth, the majority of actin granules clustered at the hyphal apex. This distinct difference in actin granule localization may be related to the distinct differences in the expansion zones of the cell wall recently demonstrated between growing buds and hyphae. The spatial and temporal dynamics of the large neck actin granules and of actin fibres are also described.
Actins↗
Collagen type distribution in healing of synthetic arterial prostheses.
Layers of tissue encapsulating vascular prostheses recovered from humans were extracted and analyzed by SDS-polyacrylamide gel electrophoresis to determine the distribution of genetically distinct collagen types. Type V collagen was in maximal concentration in extracts of tissues nearest to the prosthesis lumen, type III in extracts of chronically inflamed tissue filling the interstices of the porous prosthesis, and type I in extracts of fibrous occlusive or outer capsule tissue. This pattern of distribution of collagen types across the prosthesis wall may have arisen due to the influence of modulating factors originating in the blood flowing through the prosthesis, and factors produced by inflammatory cells chronically present at the tissue-biomaterial interface. The increased proportion of type V collagen at or near the lumen may contribute to the recognized antithrombogenic properties of human pseudointima.
Arteries↗
A positioning seat for the neonate and infant with high tone.
Positioning and seating are important for premature and young infants with tonal problems. Positioning with pillows and sandbags, the use of special handling techniques (Bobath's neural developmental treatment), as well as other specialized approaches, have not proved satisfactory in reducing tone or spasticity in these infants. We developed an adaptive seat designed to reduce extensor tone through proper positioning. This seat has also been helpful in diminishing agitation. Without these benefits, infants are often immobilized in extension and cannot actively explore their environments. Diminution in agitation has also been important in increasing interaction with nurses.
Female↗
Bone particles from toothless (tl/tl) osteopetrotic rats not cured by bone marrow transplantation are resorbed in normal littermates.
We examined the possibility that the failure of toothless (osteopetrotic) rats to be cured by bone marrow transplantation from a normal littermate is due to the production of poorly resorbable bone. Mineralized bone particles from mutants (tl/tl) and normal littermates were implanted subcutaneously in normal rats of this stock. The removal of bone and recruitment of multinucleated giant cells were evaluated by histomorphometry. No differences were found between mutant and normal bone from this stock or from two other osteopetrotic rat stocks, incisors-absent and osteopetrosis, known to be cured by bone marrow transplantation. Subject to the limitations of this method, these data suggest that the failure of tl/tl rats to be cured by bone marrow transplants from normal littermates is not due to the production of unresorbable bone or a bone matrix deficient in its ability to recruit multinucleated giant cells and presumably osteoclasts.
Animals↗
Carpal tunnel syndrome in the nonparetic hands of hemiplegics. Stress-induced by ambulatory assistive devices.
Three patients who had earlier sustained an acute stroke were admitted to a rehabilitation bed service. Clinically, they developed symptoms suggestive of carpal tunnel syndrome (CTS) in their nonparetic hands during a progressive ambulation training program which included ambulatory assistive devices. In each patient, the diagnosis was confirmed by electrodiagnostic evaluation. Two of the three patients were subsequently provided with forearm platform attachments for their assistive devices, and cock-up wrist splints, in an attempt to decrease compression of the median nerve. Despite these measures, both remained symptomatic and had electrodiagnostic evidence of progressive CTS. They were referred for surgical decompression of the median nerve. The third patient had resolution of symptoms when she became able to ambulate without need of an assistive device. These cases are examples of CTS secondary to excessive pressure in the nonparetic hands of hemiparetic patients, believed to occur more frequently than is clinically recognized.
Aged↗
The effect of heparin vs. citrate on the interaction of platelets with vascular graft materials.
Heparin is known to affect platelet function in vitro, but little is known about the effect of heparin on the interaction of platelets with polymer surfaces in general, and vascular graft materials in particular. For this reason, the effect of heparin vs. citrate anticoagulation on the interaction of platelets with the vascular graft materials expanded polytetrafluoroethylene (ePTFE), Dacron Bionit (DB) and preclotted Dacron Bionit (DB/PC) was studied in a recirculating, in vitro perfusion system. Platelet activation, as shown by a decrease in platelet count, an increase in platelet release and a decrease in platelet aggregation, was observed for all vascular graft materials tested using heparin and was greater for Dacron and preclotted Dacron than for ePTFE. Significant differences between heparin and citrate anticoagulation were seen for platelet release, platelet aggregation and the relative ranking of material platelet-reactivity. However, the trends and time course of platelet activation were similar with both heparin and citrate for the materials tested.
Adult↗