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Biomedical subjects

P Anderson

Publications and source records attributed to P Anderson.

At least 469 records · Page 26Linked to original sources
PubMed1980

Phenotypic and genetic variation in the susceptibility of Haemophilus influenzae type b to antibodies to somatic antigens.

Haemophilus influenzae type b (H.i.b) has been investigated with respect to phenotypic and genetic variations resulting in differential susceptibility to bactericidal antibody. Previous studies had shown that after growth in infected rats or in dialysate of rat serum, H.i.b strain Eag became more resistant to the bactericidal activity of antisomatic antibody. We now report that a similar phenotypic shift occurs when strain Eag is incubated with dialysate of human serum, that the increased resistance is to antibodies against determinants in the lipopolysaccharide not for the somatic antigens generally, and that most strains of H.i.b undergo the shift. To assess genetic differences in exposed antigens, a panel of 13 H.i.b isolates from cerebrospinal fluid were analyzed with cross-adsorbed antisera. Seven different patterns were found that could be accounted for through the variable expression of six antigens. These ranged from infrequent (found on 1:13 strains) to common (10:13 strains). At least four were somatic rather than capsular determinants; the most common (antigen 1) was contained in lipopolysaccharide. The epidemiologic relevance of the genetic variations was explored using pairs of isolates from two children who had had two documented infections with H.i.b. In both cases the isolates varied in somatic antigen expression. The strains from one patient differed in the expression of antigen 1. The isolates from the other were indistinguishable in sub-typing for the six classified antigens, but differed in the expression of an additional antigen identified by use of the patient's serum.

Antibodies, Bacterial↗
PubMed1980

Tumour regression as a guide to prognosis: a clinical study.

The response seen at the end of a course of radiotherapy in 116 patients with advanced carcinoma of the cervix included in hyperbaric oxygen trials was assessed by reduction in bulk and by histological examination. These patients have now been carefully followed for a minimum of three and a maximum of 13 years. The degree of regression, three and a maximum of 13 years. The degree of regression, as measured by reduction in bulk at the primary site, was as measured by reduction in bulk at the primary site, was found to predict closely the subsequent local tumour failure, survival and freedom from metastasis. The histological assessment also could be associated with the subsequent course, but the correlation was much weaker. In a trial of hyperbaric oxygen, where radiotherapy was given in 27 fractions to both groups, the immediate response was significantly better in the patients treated in oxygen, so predicting the result of the trial seen in long-term follow up. In the radiotherapy of carcinoma of cervix, reduction in bulk of the primary tumour at the end of treatment is a valuable prognostic index.

Female↗
PubMed1980

Technetium 99m-plasmin: a new test for the detection of deep vein thrombosis.

Deep vein thrombosis (DVT) is a common medical problem requiring early diagnosis and treatment in order to prevent serious sequelae. Currently available diagnostic acids are suboptimal, since they are either invasive (phlebography), insensitive (ultrasound), or slow (125I-fibrinogen uptake test). The 99Tcm-plasmin test was compared with the 125I-fibrinogen uptake test. The results were concordant in 38 of 40 cases studied (11 concordant positive and 27 concordant negative); a significant correlation (p < 0.05) was found. In a further 20 patients, the 99Tcm-plasmin uptake test was compared with X-ray contrast phlebography. In this series, 12 patients presented with concordant negative results, five patients with concordant positive results and three patients with a positive 99Tcm-plasmin uptake test in the presence of a negative phlebogram. Of these three cases, two presented with clinical evidence of pulmonary embolism and positive perfusion/ventilation lung scans. 99Tcm-plasmin appears to have the potential for early and rapid screening of deep-vein thrombosis 15 minutes after intravenous injection. The test is safe, quick, economic and easy to perform.

Fibrinogen↗
PubMed1979

Changes in production, yield, and chemical composition of corn (Zea mays) after ultrasound treatments of the seeds.

In the spring of each year (1972-1974) air-dry grains of two inbred lines of Z. mays (7275-13-1 and 106) were exposed for 17 h to a low level (25 kHz) of ultrasound and subsequently planted in the field together with untreated controls and grown to maturity. In the fall of each year the ears of each group were harvested and the number of broken stalks, the yield and weight of grains and grain parts and the alcohol-soluble amino acid complement of the grain parts were determined. Broken stalks and yields were unaffected, however the embryos from the treated groups retained more moisture than their respective controls, dry weights were also significantly increased. The alcohol-soluble amino acid composition of the embryos was markedly changed, levels of proline were severely depressed in the embryos of both lines and generally increased in the endosperms. Sonication resulted in an overall decrease of up to 40% in totalled alcohol-soluble amino acids in the grains of 7275-13-1.

Amino Acids↗
PubMed1979

Meningitis caused by Haemophilus influenzae in infant rats: protective immunity and antibody priming by gastrointestinal colonization with Escherichia coli.

Infant rats aged five to seven days were fed Escherichia coli O75:K100:H5, E. coli O13:K92:H4, or saline and five weeks later were inoculated with Haemophilus influenzae type b. The incidence of bacteremia and meningitis was significantly less (P less than 0.05) for rats fed E. coli that possessed K100 capsular antigen (cross-reactive with type b capsular antigen) than for rats fed E. coli K92 or saline. Antibody to capsular antigen was not detectable in sera obtained from rats prior to challenge with H. influenzae type b, but five days after challenge, antibody levels were significantly higher (P less than 0.001) in rats colonized with E. coli K100 than in controls. These results, together with data from passive-immunization studies, suggested that the protection against infection with H. influenzae type b was due to priming or serum anticapsular antibody, although a protective role for cell-mediated immunity and/or secretory antibody could not be ruled out. E. coli K100 primed rats vaccinated with purified H. influenzae type b antigen for a significantly increased, although transient, anticapsular antibody response.

Animals↗
PubMed1979

Antibody staining of 10-nm (100-A) filaments in cultured smooth, cardiac and skeletal muscle cells.

Antibodies were prepared against the SDS-denatured 10-nm filament protein 'skeletin' extracted from chicken gizzard. The specificity of the antibody to the 10-nm filament protein was shown by immunodiffusion before and after purification of the protein on SDS gels by the enzyme-linked immunoabsorbent assay (ELISA) and by its specific absorption with purified skeletin. In immunofluorescence (where preimmune sera and antigen-absorbed antisera gave negative results), cultured cardiac, skeletal and smooth muscle cells and endothelial cells stained intensely. No staining was observed in fibroblasts present in these cultures, nor was there staining in glial cells or nerve cell bodies and fibres from sympathetic ganglion and Auerbach's plexus cultures. Smooth muscle cells (regardless of their source and phenotypic state) and endothelial cells stained intensely in the perinuclear region and in a fine filamentous network that existed throughout the cytoplasm. In both chick and rat skeletal and cardiac muscle (cultures and frozen sections) filamentous network staining was observed, while in rat muscle the antibody was additionally localized in a regular pattern in the region of the Z-disk, and in the case of cardiac muscle associated with the intercalated disk. The addition of 10(-6) M colchicine to the culture medium of smooth and striated muscle and endothelial cells resulted in an aggregation of the filaments in the nuclear region. Cultured smooth and striated muscle and endothelial cells and freshly isolated smooth muscle cells extracted of actomyosin and tubulin by high and low ionic strength solutions gave a staining pattern similar to non-extracted cells and in the electron microscope, exhibited filaments of predominantly 10 nm diameter.

Animals↗
PubMed1978

Role of immunity in the clearance of bacteremia due to Haemophilus influenzae.

The role of antibodies to capsular and somatic antigens in the clearance of Haemophilus influenzae was investigated by active and passive immunization. The clearance index (k) and the proportion of strain b organisms cleared 30 min after intravenous administration (deltaY30) were greater in eight-week-old actively immunized rats (k = 0.693, deltaY30 = 4.07) than in nonimmune animals (k = 0.075, deltaY30 = 0.95)(P less than 0.025 for all); however, clearance correlated imprecisely with titers of bactericidal or anticapsular antibody. In three-week-old rats, intranasal immunization with strain b or U significantly increased (P less than 0.005) the rate of clearance of strains b and U. Passive immunization with antibodies to somatic or capsular antigens significantly increased the rate of clearance (P less than 0.001) and the proportion of bacteria cleared (P less than 0.05) with all test strains. The increased clearance associated with passive immunization correlated with increased splenic uptake of 32P-labeled H. influenzae (r = 0.83, P less than 0.025). Analysis of the disappearance of viable organisms and bacterial 32P suggested that bacteriolysis of H. influenzae did not occur during clearance of the bacteremia. Either antibody to capsular antigen or antibody to somatic antigen, administered or evoked in rats, accelerates intravenous clearance of H. influenzae by promotion of reticuloendothelial phagocytosis.

Animals↗
PubMed1978

Absorption and side-effects after peroral administration of sustained release iron tablets. Ferro-Retard compared with Ferronicum and Duroferon Duretter.

Study I. In 13 iron deficient patients the absorption from 100 mg ferrous sulphate (Ferro-Retard) after 3 and 5 hours was comparable to the absorption from 176 mg ferrous gluconate in rapidly disintegrating tablets (Ferronicum). Study II. (a) The serum iron elevation in 14 blood donors with normal Hb after administration of ferrous sulphate (100 mg Fe2+) in Ferro-Retard or Duroferon Duretter seemed to be equal when tested on the 4th day after donation of 450 ml blood. (b) The iron absorption, measured by the elevation of serum iron 5 and 8 hours after administration of sustained release tablets, proved to be better on the 11th and especially on the 16th day than on the 4th day after donation. Study III (side-effects). In a study on 113 subjects the total number of complaints was unusually high both before and after administration of placebo, rapidly disintegrating and sustained release ferrous sulphate tablets. The selection of participants and other methodological factors have probably been of importance. Hence, comparisons between different studies of side-effects should always be carried out with caution.

Administration, Oral↗
PubMed1978

The neurotoxicity of misonidazole and its relationship to dose, half-life and concentration in the serum.

Misonidazole has been given to a total of 87 patients. Neurotoxicity has occurred--convulsions with the higher doses and peripheral neuropathy with the lowern ones. The data from 34 patients receiving 4--7 doses has been analysed. Peripheral neuropathy is related to the total tissue exposure. By monitoring serum levels and controlling the total dose given, convulsions are avoidable and peripheral neuropathy restricted to a low and acceptable level.

Drug Administration Schedule↗
PubMed1978

Intrinsic tritium labeling of the capsular polysaccharide antigen of Haemophilus influenzae type B.

The capsular polysaccharide of Haemophilus influenzae type b was intrinsically labeled with tritium by a microculture technique with 6-3H-D-glucose and was isolated in radioantigenically pure form by a combination of selective precipitation and molecular sieve chromatography. Labeling with tritated sugar residues approached one-fourth maximum and produced a specific activity 10-fold that previously described for extrinsic labeling methods. In radioantigen-binding assays for antibody, sensitivity depended on the size of the antigen; preparations were readily made that could detect 0.01 microgram Ab/ml in serum samples of 25 microliter. Stability of the labeled antigen appears limited only by the primary radiodecomposition of tritium.

Animals↗
PubMed1977

The role of encapsulation and host age in the clearance of Haemophilus influenzae bacteremia.

Nonimmune rats given intravenous inoculations of 10(8) encapsulated Haemophilus influenzae type b cleared the bacteria at an exponential rate for 10 min; thereafter, the bacteremia plateaued at approximately 10(6) organisms/ml of blood. With 10(8) unencapsulated organisms, the initial clearance rate was significantly faster (P less than 0.001) and was complete by 30 min. The rate of clearance of a mutant strain of H. influenzae type b containing 0.1% as much capsular polysaccharide as the wild type was significantly faster (P less than 0.01), and H. influenzae type b from which a portion of the capsule had been removed physically had an intermediate clearance pattern. The addition of 1-1,000 mug of capsular polysaccharide to an inoculum of 10(8) organisms did not alter the clearance of the capsular polysaccharide-deficient mutant. The quantity of bacteria cleared during the 30 min after inoculation increased with the age of the animal. The initial bacterial clearance rate, corrected for animal and organ weight, also increased with age. These data are consistent with the proposal that physically integrated capsular polymer increases the virulence of H. influenzae type b by rendering it resistant to clearance from the bloodstream and that there may be an age-related increase in phagocytic activity that is reflected in increased clearance.

Age Factors↗