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Biomedical subjects

D Armstrong

Publications and source records attributed to D Armstrong.

At least 757 records · Page 42Linked to original sources
PubMed1966

Complement-fixation tests with cell lines derived from Burkitt's lymphoma and acute leukemias.

Armstrong, Donald (Children's Hospital of Philadelphia, Philadelphia, Pa.), Gertrude Henle, and Werner Henle. Complement-fixation tests with cell lines derived from Burkitt's lymphoma and acute leukemias. J. Bacteriol. 91:1257-1262. 1966.-Cells of various lines isolated from Burkitt's lymphomas and acute leukemias and disintegrated by freezing and thawing or sonic treatment were found to react in complement-fixation tests with a considerable proportion of human sera. At least 10(7) cells per milliliter were required for antigenic activity. All but one of 13 sera from Burkitt lymphoma patients were positive, with titers ranging from 1:8 to 1:320. About 20% of sera from American children and 60% of sera from adults, regardless of diagnosis, showed titers in a similar range. Sera giving positive tests with one of the neoplastic white cell antigens usually reacted also with many if not all of the others, but rarely with antigens derived from normal peripheral leukocyte cultures and not at all with HeLa or other human nonleukocytic cells. Various observations indicate that the complement-fixation test measures mainly antigens which are different from those detected by immunofluorescence. The nature of the reactions described remains obscure.

Adenocarcinoma↗
PubMed1966

Effect of mycoplasma on interferon production and interferon assay in cell cultures.

Armstrong, D. (The Children's Hospital of Philadelphia, Philadelphia, Pa.), and K. Paucker. Effect of mycoplasma on interferon production and interferon assay in cell cultures. J. Bacteriol. 92:97-101. 1966.-The influence of mycoplasma on the production and action of interferon was studied in cultures of both L and human embryonic kidney (HEK) cells. Mycoplasma hominis 1, the Negroni agent, and the F12 mycoplasma were used for infection of L cells, and M. hominis 1 and M. pneumoniae for inoculation of HEK cells. All strains were capable of multiplication in the culture systems employed. None produced detectable levels of interferon, and responsiveness of the cells to induction of interferon by virus remained unaltered. Infection with mycoplasma did not impair the sensitivity of the cells to the action of interferon, nor was the replication of vesicular stomatitis virus noticeably diminished.

Animals↗
PubMedDate not supplied

Acute arthritis caused by Aeromonas hydrophola: clinical and therapeutic aspects.

Two cases of Aeromonas hydrophila arthritis are reported and a third case present in the literature is reviewed. All three cases occurred in patients with myelogenous leukemia; the knee joint was involved in 2 patients and the metacarpal-phalangeal joint in the third. In the 2 patients presented here, synovial fluid antibiotic levels were measured and were adequate; but A hydrophila was repeatedly cultured from the knee joints, a fact suggesting that other factors, such as normal functioning leukocytes and specific opsonizing antibody against the organism, are also necessary to kill A hydrophila.

Acute Disease↗
PubMedDate not supplied

Laparoscopic surgery for colorectal neoplasms.

Laparoscopy is being used to assist in an increasing number and variety of bowel procedures. However, when being used for neoplastic disease concerns of margins and adequacy of mesenteric dissection must be addressed. We've performed 110 laparoscopic-assisted bowel procedures, with 45 of these performed for neoplastic disease. Ninety-two bowel resections were performed including 24 subtotal, total, or proctocolectomies. In this chapter we review the results of our series, as well as other reported series, and discuss some of the controversies involved with laparoscopy for neoplastic disease.

Colorectal Neoplasms↗
PubMedDate not supplied

Maintenance therapy: is there still a place for antireflux surgery?

Effective and safe maintenance medical therapy for uncomplicated reflux esophagitis is now feasible with omeprazole and it is likely that other H+K+ATPase blockers, and possibly very high dose H2 receptor antagonist regimens, will also be acceptable. In addition, many patients with ulceration, strictures, and Barrett's esophagus will respond to conservative medical therapy and a proportion of patients with erosive esophagitis may remain in remission with cisapride or with low dose H2 receptor antagonists, if disease is less severe. Thus, there is now a medical "gold standard" against which surgical therapy for uncomplicated esophagitis must be judged and it is essential that all future studies be conducted with clearly defined criteria for the assessment of the symptoms and endoscopic signs of esophagitis and its complications. As ever, the patient's wishes are paramount, but he or she must be allowed to select his or her therapy on the basis of a balanced and fully informed assessment of the long-term and short-term risks of all therapeutic modalities. The burdensome prospect of lifelong tablet ingestion and its potential dangers must be weighed against the alternative, in up to 30% of cases, that surgery may produce dysphagia, gas bloat, or dumping with no guarantee of a long-term cure.

Adenosine Triphosphatases↗
PubMedDate not supplied

Free radicals and aging. Electron spin resonance studies on neuronal lipopigments and cells grown in vitro.

Electron spin resonance (ESR) spectroscopy has been used in an attempt to observe free radicals which may be connected to the aging processes. Isolated lipofuscin particles from the human brain, which may act as traps for reactive ESR centers, have been studied. The lipopigments exhibit ESR signals which were attributed to metal ions. Both high-spin ferric iron and copper (II) complexes were observed. The copper resonance showed axial symmetry and the observed ESR parameters (A parallel = 185 gauss, g parallel = 2.25 and g perpendicular = 2.066) indicate that the copper ions are of the "non-blue" type (so-called "type 2"). The data suggest that the copper ions might be ligated to two nitrogen and two oxygen atoms. Ceroid particles from the brains of dogs with end-stage "canine ceroid lipofuscinosis" yield similar resonances involving metal complexes. The concentration of the copper ions in the lipopigments seems to increase slightly towards the end stage of life. Retinal pigment epithelial cells from the eyes of dogs with canine ceroid lipofuscinosis were grown in vitro and examined with ESR when the cells reached confluency and then after being maintained confluent for 2 weeks. The spectra indicate an accumulation of metal ions due to this "aging". Phase-contrast microscopy reveals an increase in perinuclear dense bodies during the time in confluency. A weak ESR signal, compatible with an "oxygen-centered" radical, was also found to increase slightly during the "aging" period.

Adolescent↗
PubMedDate not supplied

X-ray microprobe analysis of the retina and RPE in sheep with ovine ceroid-lipofuscinosis.

Ovine ceroid-lipofuscinosis (OCL) is one animal model for the human condition, and because autofluorescent lipopigments are prominent in the brain and eye, it may also prove useful as a model for aging. For example, a progressive decline in electrical recording from brain and retina are observed in both aging and OCL. Samples of retinal and retinal pigment epithelial (RPE) tissues were obtained from a young control. 2 animals with OCL and a normal aged sheep. Specimens were cryo-fractured and examined by scanning electron microscopy/x-ray microanalysis. Measurements made of 6 individual cells in the ganglion layer of OCL specimens, the remainder of the retina, and RPE showed age-related changes in zinc, iron, and copper which were associated with lipopigment accumulation in the RPE. There was marked decrease in phosphate, sulfur, and manganese levels, as photoreceptor cells and their outer segments are lost in the disease process. This is the first report of metal analysis in the retina and RPE in a disease entity, and as a function of normal aging.

Aging↗
PubMedDate not supplied

Nocardia infection in the acquired immunodeficiency syndrome.

A case of Nocardia asteroides pneumonia in a patient with the acquired immunodeficiency syndrome who was intolerant of sulfadiazine is described. On cefuroxime, the patient had a complete resolution of his Nocardia pneumonia. Disk-diffusion and broth microdilution antibiotic susceptibility testing (MIC less than or equal to 2 micrograms/ml) strongly supported the use of cefuroxime as treatment in this patient. Susceptibility testing with newer cephalosporins should be considered for all significant Nocardia isolates.

Acquired Immunodeficiency Syndrome↗