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Biomedical subjects

A Fox

Publications and source records attributed to A Fox.

At least 163 records · Page 9Linked to original sources
PubMed1985

Immunoblot analysis of serological responses in invasive aspergillosis.

The serological response to Aspergillus fumigatus was investigated in patients with pulmonary aspergillosis using the immunoblot technique. Antibody was detected against nine components of the fungus, ranging in molecular weight from 88 000 to 33 000 daltons. Antibody to a 40 000 dalton component was present in most patients (13 of 16). In surviving patients it was high (two with aspergilloma) or low but persistent (two with invasive aspergillosis). It was absent or fell in the 12 patients who died of invasive aspergillosis. Antibody to this 40 000 dalton antigen was not present in 10 sera from healthy controls. This antigen may form the basis of a more sensitive and specific serodiagnostic test for systemic aspergillosis.

Antibodies, Fungal↗
PubMed1985

Use of immunoblotting to identify antigenic differences between the yeast and mycelial phases of Candida albicans.

Western blotting was applied to the analysis of Candida albicans in the yeast and mycelial phases in an attempt to recognise mycelial specific antigens which might be of serodiagnostic value. The antisera were prepared in rabbits by immunising them with pressates of C albicans type A NCTC 3153 in the yeast phase or the mycelial phase. These were blotted against C albicans in the yeast and mycelial phases and the yeast phase of C parapsilosis, C krusei, C tropicalis, and Torulopsis glabrata. Cross reactivity was greatest against C parapsilosis. One yeast specific mannoprotein was identified with a molecular weight of 49 000. No mycelial specific antigens could be identified.

Antigens, Fungal↗
PubMed1984

A chemical and physical comparison of ferritin subunit species fractionated by high-performance liquid chromatography.

Selected chemical and physical properties were measured for different forms of ferritin subunits which had been separated by reverse-phase high-performance liquid chromatography. Ferritin subunits from porcine spleen behaved, on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, as though they were approximately Mr 2000 larger than equine spleen ferritin, whereas no difference in size was observed by gel chromatography in 6 M guanidinium chloride. All subunit species exhibited similar isoelectric focusing properties. In contrast to previous reports, no carbohydrate could be found associated with any of the isolated subunit species. Thus, the aberrant behavior of the porcine ferritin subunits between the two empirical molecular weight estimation methods appears to be the result of factor(s) other than protein intrinsic charge or covalently attached carbohydrate.

Animals↗
PubMed1984

Capillary gas chromatography-mass spectrometry of carbohydrate components of legionellae and other bacteria.

Capillary gas chromatography using fused-silica columns followed by electron impact or chemical ionization mass spectrometry was used to profile and identify neutral and amino sugars present in several legionellae and other bacteria. A modified alditol acetate derivatization method was employed to produce volatile carbohydrate derivatives. Muramic acid, a component of bacterial peptidoglycan, was detected in all legionellae examined. Heptose, a component of bacterial lipopolysaccharide, was identified in Escherichia coli organisms and in several purified Gram-negative bacterial lipopolysaccharides but not in the legionellae examined. Two amino dideoxyhexoses were found to be present in several of the Legionellae examined. The potential of gas chromatography-mass spectrometry for the direct chemical characterization of microorganisms is discussed.

Amino Sugars↗
PubMed1984

Experimental uveitis. Elicited by peptidoglycan-polysaccharide complexes, lipopolysaccharide, and muramyl dipeptide.

Uveitis could be a reaction to bacterial debris disseminated to the eye from extraocular sites of infection. In this study, we relate the composition of several bacterial components to their inflammatory properties in the eye. Groups of rabbits were injected intravitreously with peptidoglycan-polysaccharide (PG-PS) complexes isolated from group A streptococci, Escherichia coli lipopolysaccharide (LPS), or synthetic muramyl dipeptide (MDP). The lipid A region of LPS and the glycan backbone of PG are chemical analogues; MDP is the minimal biologically active subunit of PG. All of these molecules elicited uveitis as observed both clinically and histologically. The MDP elicited an acute inflammation characterized by a heterophil and monocyte infiltrate that subsided within 16 days. The PG-PS and LPS elicited chronic inflammation characterized by mononuclear and lymphocyte infiltration and severe necrosis of the retina.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1984

Clinico-radiological spectrum of giant supraclinoid internal carotid artery aneurysms. Observations in 93 cases.

A review of a series of 312 giant intracranial aneurysms treated at University Hospital in London, Ontario, showed that 93 of those aneurysms were located between the intracavernous portion and the bifurcation of the internal carotid artery. Sixty-five of those aneurysms were carotid ophthalmic, 12 were located in the internal carotid-posterior communicating-anterior choroidal artery regions and 16 involved the internal carotid artery bifurcation. For the majority, clinical presentation was related to the mass of the aneurysms and compression of surrounding structures such as visual pathways, ocular motor cranial nerves, the fifth nerve, and hypothalamic-pituitary axis. Fourteen patients presented with subarachnoid hemorrhage. Cerebral angiography, computed tomography and xenon inhalation studies of cerebral blood flow were the tools used to study the morphology of the aneurysm and dynamics of the circle of Willis.

Brain↗
PubMed1984

Capillary gas chromatographic analysis of carbohydrates of Legionella pneumophila and other members of the family Legionellaceae.

Legionella pneumophila, the causative agent of Legionnaires disease, and related organisms have previously been characterized primarily by conventional bacteriological methods, DNA-DNA hybridization, antigenic analysis, and fatty acid analysis. By capillary gas chromatographic analysis for carbohydrates, we have shown that muramic acid and glucosamine, characteristic markers of bacterial cell walls, were present in samples of L. pneumophila and a group of legionella-like organisms. Some bacterial samples contained two unusual isomeric aminodideoxyhexoses (X1 and X2). L. pneumophila was characterized by the absence of fucose and the presence of the peak X1. Tatlockia micdadei (Legionella micdadei) was distinguishable by the presence of large amounts of rhamnose and fucose and by the absence of X1 and X2. Fluoribacter strains were much more variable in their carbohydrate composition. These data suggest that, in addition to other reported techniques, carbohydrate profiling by capillary gas chromatography can be a valuable diagnostic method in reference microbiology laboratories for differentiating members of the family Legionellaceae.

Carbohydrates↗
PubMed1984

A cyclophosphamide-sensitive suppressor T cell circuit induced by thermal injury.

The immunoregulatory events leading to the generation of suppressor T cells after burn injury were studied by means of a mouse burn model. Immunoresponsiveness was assessed on various postburn days with a primary in vitro mixed lymphocyte reaction (MLR). Responses of burned mice were depressed between 3 and 14 days after burn. Suppression became significant 5 days after burn and remained so through 14 days after burn. The Ly-t surface phenotype of T cells was studied on days 5 and 7 after burn. On day 5 burn, T cells responsible for suppression bore an Ly-1+, 2- phenotype. By postburn day 7 suppressor T cells bore an Ly-1-,2+ phenotype. These observations are consistent with the notion of feedback suppression after burn injury, wherein Ly-1+, 2- T cells induce a subset of Ly-1+,2+ T cells, thereby generating Ly-1-,2+ suppressor effector T cells. An attempt was made to uncouple the putative suppressor inducer and the suppressor effector using low doses of cyclophosphamide (CY). A single dose of 25 mg CY/kg resulted in transient restoration of depressed burn responses. By using multiple sequential doses of CY, this restorative effect could be prolonged through 8 days after burn. A dosage schedule that restores responses of burn cells without affecting responses of control cells is presented.

Animals↗
PubMed1984

Income changes at and after Social Security benefit receipt: evidence from the Retirement History Study.

This article details the changes in total income and the composition of its sources that occur upon initial receipt of Social Security benefits, and in the first 4 years thereafter. The study shows that, for many persons, "retirement" is a gradual process rather than an immediate cessation of all paid work. About half the persons entering the rolls continue at least some paid employment after benefit receipt. Even more do so if previous earnings were low or if they have no pension to supplement their benefits. In real terms, the average couple initially loses about one-third of its previous income, while nonmarried women, with less to begin with, lose somewhat less. In the time period studied, inflation was high in historical terms: the Consumer Price Index rose by approximately one-third in the 4-year period following benefit receipt. During that time, the real income of beneficiaries declined by about 10 percent from the levels immediately after benefit receipt. Fewer beneficiaries continued to work 4 years later, so earnings played a smaller role in total income. The real value of private pensions declined by about 20 percent in the 4-year period, but because most persons with such pensions had other, better-protected sources of income, their total income declined by less than 10 percent.

Aged↗
PubMed1984

Two curved rods in non-specific vaginitis.

Sixteen isolates from the vaginal discharge of women with bacterial vaginosis (non-specific vaginitis) and six provided by other investigators were divided into two groups on the basis of morphology and biochemical tests. Only one organism type was isolated from any one patient. The two groups differed in size, number of flagella, enzyme production, ability to ferment carbohydrates, hydrolyse hippurate and arginine, reduce nitrate, and produce ONPG, and in sensitivity to metronidazole. Both groups fermented glucose and maltose, produced succinate from glucose and alpha-glucosidase and leucine arylamidase.

Bacteria, Anaerobic↗
PubMed1983

Capillary gas chromatographic analysis of alditol acetates of neutral and amino sugars in bacterial cell walls.

Several improvements in the preparation of alditol acetates of neutral and amino sugars and in the preparation of glass capillary columns for their separation are described. Modifications in sample preparation permitted the simultaneous processing of multiple samples and eliminated extraneous background peaks. Efficient and inert columns were tailor-made for the separation of alditol acetates of neutral and amino sugars by leaching glass capillaries with aqueous hydrochloric acid and dynamically coating with SP-2330.

Acetates↗
PubMed1983

Metronidazole in treatment of non-specific vaginitis. Clinical and microbiological findings in ten patients given 2 grams of metronidazole.

A 2 gram single dose of metronidazole was given to ten patients suffering from nonspecific vaginitis. At follow-up a week later seven of these patients were clinically and microbiologically free from infection. The remaining three patients had persisting symptoms and both clinical and microbiological findings confirmed treatment failure. Despite the small numbers entered into the trial to date, a cure rate of only seven out of ten patients suggests that a 2 gram single dose of metronidazole is inadequate treatment for non-specific vaginitis.

Bacterial Infections↗
PubMed1983

Purchasing power of U.S. Social Security benefits abroad, 1970-82.

This article examines whether the small number of Social Security beneficiaries living abroad enjoy a higher standard of living than they would with the same benefits if they lived in the United States. The article addresses this question using two methods. First, absolute comparisons of U.S. dollar purchasing power abroad are made using "purchasing power parities," a method recently developed to allow international comparisons of real standards of living. Second, the effects of changes in Social Security benefit levels, exchange rates, and rates of inflation on the relative value of benefits abroad are measured. Both methods show considerable instability in purchasing power of Social Security benefits in the 1970's. Although beneficiaries in 1970 generally could live better abroad than in the United States, this advantage eroded considerably during the 1970's, followed by some improvement in 1981-82.

Economics↗
PubMed1982

Arthropathic properties related to the molecular weight of peptidoglycan-polysaccharide polymers of streptococcal cell walls.

The covalently bound polymers of peptidoglycan and group-specific polysaccharide (PG-APS) were isolated from the cell walls of group A streptococci. Arthritis was induced in rats with a single intraperitoneal injection of an aqueous suspension of PG-APS fragments derived by sonication. The joint lesions induced with this polydisperse suspension followed a bimodal pattern consisting of an acute phase, which reached a peak 5 days after injection and then receded, followed by a chronic, remittent, erosive arthritis lasting several months. The relative severities of the acute and chronic phases could be manipulated by selection of the size of PG-APS fragments. The fragments of PG-APS obtained by sonic treatment were resolved on the basis of size into three major populations by sucrose gradient or differential centrifugation. Based upon light scattering and gel filtration, the average molecular weight of the largest family of fragments was estimated to be about 500 x 10(6), the intermediate fragments were 50 x 10(6) daltons, and the predominant size in the smallest population was 5.3 x 10(6) daltons. The larger fragments induced negligible acute inflammation, but chronic disease became apparent 5 to 9 weeks after injection. The smallest fragments induced the most severe acute inflammation, with relatively little late, chronic joint disease. The particles of intermediate size induced moderate acute inflammation and the most severe chronic, erosive joint lesions. A single injection of fragments of the isolated peptidoglycan moiety of the PG-APS induced only a moderate acute inflammation of joints, with no apparent capacity to maintain the injury and induce chronic disease.

Animals↗
PubMed1982

Measurement of bacterial cell wall in tissues by solid-phase radioimmunoassay: correlation of distribution and persistence with experimental arthritis in rats.

We have developed sensitive and specific solid-phase radioimmunoassays to quantitate the distribution and persistence of bacterial antigen in rats developing arthritis in response to a single injection of streptococcal cell wall material. Three separate assays were specific for either the A polysaccharide (N-acetyl-D-glucosamine), A-variant polysaccharide (polyrhamnose), or peptidoglycan (D-ala-D-ala) moieties of the streptococcal cell wall. Antigen was detected in all tissues surveyed, although the greatest amount was in the liver and spleen. By using three fractions of cell wall separated by size, we have shown that the development of arthritis correlates with the degree of cell wall deposited and persisting in the joints. Further statistical analyses suggested differences in metabolism by different tissues and differential metabolism of different antigenic epitopes in some cases.

Acetylglucosamine↗
PubMed1982

Embolization of cerebral arteriovenous malformations with bucrylate.

Forty-six patients with cerebral arteriovenous malformations (AVM's) were selected for embolization with bucrylate. These patients were assigned to three different groups. Group I consisted of 22 patients with nonresectable AVM's who were selected for embolization with a Silastic calibrated-leak ballon. In 16 or these patients, embolization was achieved, with partial obliteration of the AVM in 14 and complete obliteration in two. Five patients had subarachnoid hemorrhage caused by the balloon bursting and concomitant dissection of the feeding vessel. Four of these patients recovered completely and one died of a brain-stem hemorrhage. A permanent field defect was noted in five cases, and two patients had a transient mild neurological deficit. Group II consisted of 13 patients treated by intraoperative embolization. Complete obliteration by embolization was obtained in four cases, and complete surgical resection after embolization in five. Partial embolization with no surgical resection was achieved in five cases. Three of these patients had a permanent mild neurological deficit and two had transient deficits. There was no mortality in this group. Group III consisted of 11 patients treated by embolization with bucrylate using a new latex calibrated-leak balloon. This balloon has a higher malleability, and takes on the exact configuration of the feeder, with no risk of dissection. This balloon also permits delivery of the faster and larger injection of bucrylate to the arterial feeders of the AVM. Two AVM's were completely obliterated, and embolization was only partially successful in the other cases. Neurological complications consisted of incomplete field defects in two cases, slight memory loss in one case, and transient clumsiness of the arm and face in one case. Two patients have a catheter permanently glued in the malformation, with no neurological complication. There was no mortality in this group.

Adolescent↗
PubMed1982

Earnings replacement rates and total income: findings from the retirement history study.

This article describes and reports on the degree to which Social Security and private pensions replaced preretirement earnings for a sample of individuals retiring in the early 1970's. Although simple in concept, replacement rates can be defined in many different ways. Because no one definition is best for all purposes, several are considered, and the contexts in which each might be utilized are discussed. Both Social Security and total replacement rates are presented for individual retired workers and married couples. Also presented are rough estimates of changes in total income at retirement.

Aged↗