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Biomedical subjects

A Shaw

Publications and source records attributed to A Shaw.

At least 199 records · Page 11Linked to original sources
PubMed1986

Defined Plasmodium falciparum antigens in malaria serology.

The study evaluates three enzyme-linked immunosorbent assays (ELISA) of malaria antigens suitable for use in large-scale epidemiological studies. Results obtained using sera from 567 persons from the Gambia indicated that the micro-ELISA method using parasitized red blood cell extract did not reliably quantitate antimalarial antibodies, especially in young children. In contrast, two micro-ELISA methods that employed purified, defined antigens (a polypeptide of M(r) = 41 000 present in rhoptries, and a 31-1 fusion polypeptide corresponding to a merozoite surface antigen) permitted the precise determination of antimalarial antibodies in both adults and children. Problems and advantages associated with the use of the M(r) = 41 000 and 31-1 antigens for the determination of antimalarial antibodies are discussed.

Antigens, Protozoan↗
PubMed1985

Molecular cloning and expression of human tumor necrosis factor and comparison with mouse tumor necrosis factor.

U-937 cells, a monocytic line derived from a human histiocytic lymphoma, were induced for human tumor necrosis factor (TNF) secretion into the medium and were used for the preparation of TNF mRNA. Biological activity of the latter was quantified in a Xenopus laevis oocyte injection system. TNF mRNA was enriched by gradient centrifugation and this size-fractionated mRNA was used for synthesis of cDNA and inserted into the unique PstI site of pAT153. A recombinant plasmid containing human TNF cDNA was selected by colony hybridization using an internal fragment of a mouse TNF cDNA clone [Fransen, L., Mueller, R., Marmenout, A., Tavernier, J., Van der Heyden, J., Kawashima, E., Chollet, A., Tizard, R., Van Heuverswyn, H., Van Vliet, A., Ruysschaert, M. R. & Fiers, W. (1985) Nucleic Acids Res. 13, 4417-4429] as a probe. The sequence of this human TNF cDNA is in agreement with the one published by Pennica et al. [Pennica, D., Nedwin, G. E., Hayflick, J. S., Seeburg, P. H., Derynck, R., Palladino, M. A., Kohr, W. J., Aggarwal, B. B. & Goeddel, D. V. (1984) Nature (Lond.) 312, 724-729]. The 157-amino-acid-long mature sequence is about 80% homologous to mouse TNF and its hydrophilicity plot is also very similar, in spite of the apparent species specificity of TNF. In contrast to mouse TNF, it contains no potential N-glycosylation site. When compared to other cytokines, like IFN-beta, IFN-gamma, or IL-2, there is a remarkably high preference for G X C pairs in the third-letter positions. Expression of the TNF cDNA in monkey COS cells or in Escherichia coli gives rise to a protein having similar biological and serological properties as natural human TNF. A human genomic clone was also identified and sequenced; it was found to be in good agreement with the one recently published by Shirai et al. [Shirai, T., Yamaguchi, H., Ito, H., Todd, C. W. & Wallace, R. B. (1985) Nature (Lond.) 313, 803-806], except for some differences in the introns and 5'-untranslated region.

Amino Acid Sequence↗
PubMed1985

Familial visceral myopathy: the role of surgery.

Familial visceral myopathy is a form of chronic intestinal pseudoobstruction in which fibrosis of the smooth muscle of the alimentary tract causes protean symptoms of disordered visceral motility. Based on our 8 year observation of six members of one family with familial visceral myopathy and review of the few well-documented case reports of this disease, we have confirmed a role for surgeons in tissue diagnosis, case identification, and palliation of incapacitating symptoms of familial visceral myopathy after obtaining dynamic radiographic assessment of the entire alimentary canal. Because the duodenum and colon are the usual sources of major dysmotility symptoms, patients incapacitated by duodenal or colonic pseudoobstruction may benefit from bypass or resective operations.

Adult↗
PubMed1985

Noise transfer in screen-film subtraction radiography.

The transfer of noise through the stages of a screen-film subtraction process was investigated. In particular the effect of measuring aperture size and film density on the measured noise granularity was studied. The relative contributions of quantum noise and film grain noise were found to depend on both aperture and density. Noise measurements are presented for a medium speed screen-film combination and also for a low noise alpha 16-Kodak Industrex C system. The effect of grain mottle and film blur on noise transfer through the multiple print process employed in subtraction radiography is demonstrated.

Humans↗
PubMed1985

Surgical complications of neuroblastoma resection.

Locally advanced neuroblastomas in infants and very young children often require intricate dissection to separate the tumors from the anatomic structures that they have enmeshed. The rationale for these procedures is based mainly on the premise that near-total resection is almost as effective as total extirpation, given favorable circumstances of age and stage. The principal reason for not undertaking or aborting such resections has been to avoid the fallacy of intentionally sacrificing vital structures, causing serious disability, in circumstances in which cure is either impossible or equally likely to accrue from a lesser procedure. This report describes five surgical mishaps, two of which resulted in postoperative deaths. The potential for these complications was greatest during resection of locally advanced tumors in small babies. We suspect that this hazard is more prevalent than its scarcity in the literature would suggest and that potential for unintended injury should be a prominent factor in the decision to proceed or desist with resection of a large neuroblastoma.

Child, Preschool↗
PubMed1984

Reduction to benzidine is not necessary for the covalent binding of a benzidine azodye to rat liver DNA.

The DNA binding of 2 benzidine azodyes, Congo Red and Direct Blue 6, was compared in rat liver. Both dyes showed binding consequent upon metabolism to benzidine, and in each case hydrolysis of the liver DNA yielded N-(deoxyguanosin-8-yl)-N'-acetylbenzidine. The majority of Direct Blue 6-derived radioactivity bound to DNA was present as at least one other novel species. Our preliminary work on the major Direct Blue 6 DNA adduct suggests its structure may be disodium 8-amino-2-[4-(N-deoxyguanosin-8-yl)-aminobiphenyl-4'-yl] azo-1-hydroxynaphthalene-3,6-disulphonate. This adduct may form as a result of the susceptibility of the dye to hepatic azoreductase and its apparent existence may explain the observed potent carcinogenicity of dyes such as Direct Blue 6.

Animals↗
PubMed1984

Esophageal atresia with double fistula: the missed anomaly.

Of the various anatomical types of atresia, that of esophageal atresia and double fistula is said to be the least common. In most series, frequency is less than 1%. Seventy-eight patients with esophageal atresia were treated at the University of Virginia Medical Center between 1955 and 1983. Six of them had esophageal atresia and double fistula, and in 5 of these 6, this anomaly was not diagnosed preoperatively and was not detected intraoperatively. Our experience suggests that proximal "pouchograms" are essential in the preoperative evaluation of these patients to detect the presence of esophageal atresia and double fistula. The morbidity and mortality occasioned by overlooking this anomaly far exceed the risk of the contrast study.

Barium Sulfate↗
PubMed1984

Medishield AGS system and servo 900 ventilators. Investigation and remedy of hazard caused by defeat of 'low expired minute volume' alarm.

The use of the new Medishield anaesthetic gas scavenging system with ventilators in the Siemens-Elema Servo 900 series was investigated. It was discovered that this combination of equipment creates the hazard that a disconnexion in the patient breathing system may not be detected by the ventilator alarm. This happens because the suction generated by the scavenging system draws a considerable flow of room air through the expiratory system of the ventilator when a disconnexion occurs. Possible solutions to the problem were investigated, and it was discovered that the problem can be overcome by applying a small amount of positive end-expiratory pressure to counteract the suction from the scavenging system.

Air Pollution↗
PubMed1984

Bilateral adrenal neuroblastoma.

A 3-month-old female with bilateral adrenal neuroblastoma had a unilateral adrenalectomy followed by cyclophosphamide treatment for 2 years. At 7, she has no evidence of disease. The favorable course of this patient and that of another young child reported with bilateral neuroblastoma as well as wide-spread metastases suggests that bilateral adrenalectomy may not be necessary for a child under 1 year of age with bilateral disease.

Adrenal Gland Neoplasms↗
PubMed1983

Improved conditions for the production of monoclonal antibodies to carcinogen-modified DNA, for use in enzyme-linked immunosorbent assays (ELISA).

The methodology for the production of monoclonal antibodies to chemical carcinogen-modified DNA has been improved to provide high yields of hybridomas, using guanine-imidazole ring-opened aflatoxin B1-modified DNA as an example (iro-AFB1 DNA). The percentage of immunised mice which responded to iro-AFB1 DNA-protein immunisation and the number of specific hybridomas produced was dependent on the level of modification of DNA. One in three BALB/c mice had detectable (but low) antibody titre when 0.3% modified iro-AFB1 DNA was used and this yielded 2 specific hybridomas, whereas all mice responded at reasonable titres and 6 specific hybridomas were obtained when 3% modified iro-AFB1 DNA was used. Other factors found to improve the number and titre of mice responding to immunisation and the yield of hybridomas were: KLH greater than BSA as carrier protein, C57 BL/6 X BALB/c F1 greater than BALB/c mice for antibody production, fusion success and ascites growth. The conditions limiting the sensitivity and reproducibility of an enzyme-linked immunosorbent assay (ELISA) using these monoclonal antibodies with beta-galactosidase-linked sheep F(ab')2 anti-mouse IgG as the second antibody were also tested. Present experience with AFB1 and other carcinogens indicates that these methods should be applicable to the production of monoclonal antibodies to DNA modified by a wide variety of chemical carcinogens.

Aflatoxin B1↗