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Biomedical subjects

D C Anderson

Publications and source records attributed to D C Anderson.

At least 469 records · Page 26Linked to original sources
PubMed1981

Assessment of Haemophilus influenzae type b opsonins by neutrophil chemiluminescence.

A luminol-enhancement chemiluminescence assay and a radiolabeled uptake assay were developed to assess opsonins for Haemophilus influenzae type b. Opsonins in acute and convalescent sera from 17 children with H. influenzae type b meningitis, along with pooled normal human sera, were evaluated and compared with anti-polyribosephosphate antibody concentrations. Five children had a rise in the chemiluminescence-area under the curve for convalescent compared with acute sera. Patient chemiluminescence--area-under-the-curve values were significantly (P less than 0.05) more likely to exceed 50% of normal human serum values if sera contained greater than or equal to 0.1 microgram of anti-polyribosephosphate antibody per ml. Magnesium ethylene glycol tetraacetic acid chelation and heat inactivation of patient and normal human sera significantly (P less than 0.05) reduced chemiluminescence--area-under-the-curve activity. Thus, complement appears to contribute significantly to the opsonization of H. influenzae type b in sera of children. Two of nine children had increases in opsonins as assayed by 3H-labeled H. influenzae type b uptake. After natural systemic H. influenzae type b infection, young children are unable to respond acutely with an increase in anti-polyribosephosphate antibody or serum opsonic activity.

Antibodies, Bacterial↗
PubMed1981

Congenital adrenal hyperplasia in a 66-year-old female.

A 66-year-old genotypically female patient was reared as a man. Investigations showed a partial adrenal 21-hydroxylase deficiency, and pituitary gonadotrophin secretion typical of a post-menopausal woman.

Adrenal Hyperplasia, Congenital↗
PubMed1981

Abnormal mobility of neonatal polymorphonuclear leukocytes. Relationship to impaired redistribution of surface adhesion sites by chemotactic factor or colchicine.

To determine the mechanism(s) of diminished, stimulated, and directed migration of neonatal (N) polymorphonuclear leukocytes (PMN), chemotactic factor (CF) sensory and PMN effector functions were studied in healthy N and adult or maternal controls (C). N PMN demonstrated high affinity binding for N-formyl-methionyl-leucyl-[3H]phenylalanine (fMLP), which was saturable between 40 and 100 nM as observed with C PMN. The kinetics of binding and the characteristics of dissociation of binding by N PMN were equivalent to control PMN. Both "threshold" and "peak" concentrations (1 and 10 nM, respectively) of fMLP effected comparable PMN chemiluminescence among neonates and controls. An equivalent threshold concentration (0.05 nM) of fMLP effected N and C PMN shape change in suspension, and a maximally effective concentration (5 nM) induced comparable bipolar configuration, although uropod formation was only 38 +/- 8% of N PMN, compared with 73 +/- 11% of C PMN (P less than 0.01). Striking abnormalities of N PMN adherence were identified: mean +/- SD base-line (unstimulated) N adherence values (39 +/- 8%) were equal to C (38 +/- 9%), but diminished increments in response to single CF stimuli were noted among N (fMLP: 42 +/- 7% (N), 70 +/- 11% (C); C5a: 41 +/- 6% (N), 68 +/- 6% (C); BCF: 41 +/- 6% (N), 63 +/- 9% (C), P less than 0.01 for each CF). On sequential exposure to increasing concentrations of CF N PMN failed to demonstrate expected decreased adherence values; sequential stimuli with fMLP (0.1 nM, 10 nM) or C5a (8 microgram protein/ml, 32 microgram protein/ml) effected mean +/- 1 SD values of 51 +/- 9% (N), 30 +/- 9% (C), and 34 +/- 10 (N), 48 +/- 14% (C), respectively. As demonstrated with a latex bead-binding technique, N PMN failed to redistribute adhesion sites to the cell's tail under the same experimental conditions; in 21 N samples studied, restricted unipolar binding occurred in 33 +/- 8% (fMLP) or 37 +/- 7% (C5a) of PMN in contrast to C values of 70% (fMLP), or 71% (C5a), P less than 0.001. Similar findings were observed when PMN were preincubated with colchicine (25 microgram/ml); expected diminished adherence scores (compared with base-line values) were demonstrated with C PMN but not with N cells, P less than 0.01. Additionally colchicine-induced redistribution of adhesion sites as was observed with C samples (72 +/- 14% unipolar binding) was significantly (P less than 0.001) less among N PMN (31 +/- 11% unipolar binding). These investigations indicate that CF sensory mechanisms of N PMN are normal, compared with healthy adult or maternal controls. Diminished stimulated locomotion of the N PMN may be functionally related to reduced modulation of cell adhesiveness by chemotactic stimulation.

Cell Adhesion↗
PubMed1981

Echocardiography in diagnostic assessment of stroke.

We assessed the use of echocardiography in the evaluation of stroke by recording M-mode and two-dimensional (2D) echocardiograms in 100 consecutive hospitalized patients. Of the 95 persons satisfactorily imaged with 2D echocardiography, 47 lacked clinical and routine laboratory evidence of heart disease; no potential embolic source or other finding that altered therapy was diagnosed by echocardiography. In the remaining 48 patients with clinical or routine laboratory evidence of heart disease, two with left ventricular thrombus as a potential embolic source were identified by 2D echocardiography. M-mode echocardiograms failed to detect the thrombus in either patient. No patients with left atrial thrombi, mitral stenosis, cardiac tumor, or vegetations suggesting endocarditis were identified. One patient had possible mitral valve prolapse. Echocardiograms in patients lacking other available evidence of heart disease are unlikely to yield findings that alter the clinical approach to patients with stroke; echocardiography in stroke patients with clinically evident heart disease may have greater clinical utility; additional study of the role of echocardiography in selected subgroups of stroke patients is indicated.

Adult↗
PubMed1980

Determination of the equilibrium distibution between alcohol and aldehyde substrates when bound to horse liver alcohol dehydrogenase using magnetic resonance.

The interactions of horse liver alcohol dehydrogenase (LADH) with the rho-trifluoromethyl derivatives of benzyl alcohol, benzaldehyde, and benzoic acid have been investigated by use of 19F nuclear magnetic resonance. The aldehyde and alcohol are good substrates for the enzyme and display kinetic characteristics similar to other alcohol/aldehyde pairs. In single-turnover experiments with NADH, rho-(trifluoromethyl)benzaldehyde shows biphasic kinetics similar to those shown by other aromatic aldehydes, which led Bernhard and co-workers [Bernard, S. A., Dunn, M. F., Luisi, P. L., & Shack, P. (1970) Biochemistry 9, 185] to propose half-of-the-sites reactivity for this enzyme. Fluorine magnetic resonance demonstrates that under equilibrium conditions at 4 degrees C and pH 8.75 rho-(trifluoromethyl)benzyl alcohol binds to LADH with a dissociation constant of 1 x 10(-3) M. Addition of 1 equiv of NAD to a stoichiometric complex of LADH and the alcohol generates a discrete resonance. This resonance corresponds to the ternary complex of LADH, NAD, and alcohol with little contribution from the NADH and aldehyde ternary complex. Quantitation shows that the bound NAD-alcohol pair is favored by at least a factor of 20 over the bound NADH-aldehyde pair at equililbrium. These results are consistent with explanations for the biphasic kinetics which involve half-of-the-sites reactivity of multiple steps in the reaction of each catalytic site. These results eliminate explanations for the biphasic kinetics of this system which require this equilibrium constant to have a value near unity or those which give greatest thermodynamic stability to the heterodimer LADH [(NAD-alcohol)(NADH-aldehyde)].

Alcohol Oxidoreductases↗
PubMed1980

The adrenal androgen-stimulating hormone does not exist.

The existence of a separate but so-far-unidentified pituitary cortical androgen-stimulating hormone that acts in concert with adrenocorticotrophic hormone (ACTH) to stimulate adrenal androgen production (the "adrenarche") from mid-childhood onwards is still strongly argued. It is suggested here that the postulated hormone does not exist and that the adrenarche, which parallels the development of the inner zone, the zona reticularis, is best explained by a morphological and functional change in the inner cells that is induced locally by high levels of cortisol. Downstream "pollution" and slow flush-out of reticularis blood vessels after each pulse of ACTH would expose the inner-zone cells to the highest cortisol levels for the longest time.

Adolescent↗
PubMed1980

Neutropenia and impaired neutrophil migration in type IB glycogen storage disease.

The association of neutropenia with type IB glycogen storage disease was observed in siblings. Biochemical studies of liver demonstrated a defect in glucose-6-phosphate transport. Neutrophil mobilization in vivo was impaired but the bone marrow was normal histologically. In vitro studies of neutrophils indicated a defect in random and directed cell migration. The studies suggest that a role for glucose-6-phosphate transport in neutrophils should be considered.

Agranulocytosis↗
PubMed1980

Luminol-enhanced chemiluminescence for evaluation of type III group B streptococcal opsonins in human sera.

A luminol-enhanced chemiluminescence (CL) assay was developed to evaluate type III group B streptococcal opsonins. Sera from 11 adults that contained high (greater than 25 microgram/ml), intermediate (3-24 microgram/ml), or low (less than 2 microgram/ml) antibody concentrations were assessed by CL, indirect immunofluorescence (IF), and bactericidal assays. Total CL activity correlated with antibody concentration (P less than 0.005), IgG- and C3-IF values, and phagocytic and bactericidal indices. Heat-stable CL activity correlated with antibody concentration (P less than 0.0001) and was related to IgG-IF values and phagocytic indices. Significant bactericidal activity was demonstrated in all sera containing greater than 2 microgram of antibody/ml, but no bactericidal activity was observed in heat-inactivated sera. Adsorption of heated sera with type III group B Streptococcus abolished CL activity, whereas CL values of MgEGTA-chelated sera were approximately 80% of untreated sera. Thus, type-specific antibody in addition to heat-labile serum factors, including those of the alternative complement pathway, contribute to opsonization of type III group B Streptococcus.

Antigen-Antibody Reactions↗
PubMed1980

Heat-labile enterotoxigenic Escherichia coli induced diarrhea aboard a Miami-based cruise ship.

Beginning in late December, 1975, almost one-third of the passengers on two successive cruises of a Miami-based cruise ship noted the onset of diarrheal illness while on board. A single serotype of Escherichia coli that produced heat-labile enterotoxin without producing heat-stable enterotoxin was recovered from the stool of most ill passengers cultured. Epidemiological investigation could not specifically define the mode of spread. The clinical picture presented was similar to the illness caused by enterotoxigenic E. coli that produce only heat-stable enterotoxin or that produce heat-stable and heat-labile enterotoxins.

Diarrhea↗
PubMed1980

Twenty-four hour profiles of serum prolactin during male puberty with and without gynaecomastia.

Twenty-four hour profiles of circulating prolactin have been documented in eight boys with simple delayed puberty, eleven with gynaecomastia, three of whom were retested following its spontaneous resolution, and two normal adult men. Mean 24 h prolactin levels in four boys with delayed puberty and ten with gynaecomastia exceeded the mean levels for the two adult men. A sleep-associated rise in prolactin levels occurred at all stages of puberty irrespective of the presence or absence of gynaecomastia, and in some subjects peaks also occurred during the daytime. Boys with gynaecomastia had higher 24 h means levels of prolactin (P less than 0.05), higher daytime levels (P less than 0.05) and higher sleep-associated levels (P less than 0.05) than did control subjects. These were not related to the degree or duration of the gynaecomastia, but 24 h mean levels of prolactin and oestradiol were positively correlated. In one subject who had had transient galactorrhoea, high levels of circulating prolactin, oestrone and oestradiol fell following spontaneous resolution of the gynaecomastia. We believe that oestrogen: androgen imbalance during the daytime is the major cause of pubertal gynaecomastia, with hyperprolacinaemia (which may cause galactorrhoea) sometimes occurring as a response to relative hyperoestrogenaemia.

Adolescent↗
PubMed1980

Airborne spread of brucellosis.

review of epidemic and endemic brucellosis at six abattoirs demonstrates a correlation between case distribution and flow of air from the kill department (stage II) to other areas within an abattoir. Air from the kill department disseminated to nearby departments led to abnormally high brucellosis attack rates for persons who worked in these areas at two abattoirs. Complete physical separation or maintaining negative air pressure in the kill department was associated with reduced risk for workers in other areas at four abattoirs. Cases in persons who had exposure to kill department air but no contact with animal tissues provide strong evidence for airborne transmission of infection. Brucellosis is also contracted through skin contact with infectious animal tissues, but this route of transmission appears less important than formerly believed.

Abattoirs↗
PubMed1980

In vitro susceptibility of 104 clinical isolates of Haemophilus influenzae to moxalactam (LY127935), ampicillin, chloramphenicol, and ticarcillin.

A total of 104 strains of Haemophilus influenzae isolated from pediatric patients over a 1-year period were tested for susceptibility to moxalactam (LY127935), ampicillin, chloramphenicol, and ticarcillin. Of these strains, 30 produced beta-lactamase. LY127935 inhibited 99% of the strains at a concentration of 0.125 microgram/ml; the remaining strain was inhibited by this antibiotic at 0.25 microgram/ml. beta-Lactamase-producing strains were inhibited by ampicillin at greater than or equal to 2 microgram/ml. beta-Lactamase-negative strains were all inhibited by ampicillin at less than or equal to 1 microgram/ml, except for one nontypable strain which required 2 microgram of ampicillin per ml for inhibition. All strains were susceptible to chloramphenicol at less than or equal to 4 microgram/ml. beta-Lactamase-producing strains were less susceptible (geometric mean = 4.702 microgram/ml) to ticarcillin than were strains which did not produce beta-lactamase (geometric mean = 0.331 microgram/ml). LY127935 susceptibility was not influenced by increasing inoculum size, as ws ampicillin susceptibility. Combinations of LY127935 and chloramphenicol or ampicillin were not antagonistic in vitro.

Ampicillin↗