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Biomedical subjects

M S Leffell

Publications and source records attributed to M S Leffell.

50 records · Page 3Linked to original sources

Reversal of skin test anergy during maintenance hemodialysis by protein and calorie supplementation.

The effect of protein and calorie supplementation on the immune function of two maintenance hemodialysis patients was assessed. Before nutritional supplementation, both patients were anergic to four skin test antigens and had low relative percentages and absolute number of T lymphocytes. After 3 months of nutritional supplements both patients responded to in vivo skin testing to at least two antigens and in both patients, the relative percentage and absolute number of T lymphocytes increased. These two cases illustrate that the defect in cell-mediated immunity and impaired delayed cutaneous hypersensitivity which is known to occur in hemodialysis patients may be a reversible manifestation of protein-calorie malnutrition.

Food, Fortified↗

Serum complement activity in pre-term pregnancies: relationship to duration of ruptured membranes and clinical infection.

Physiologic changes occurring during the latent period of prematurely ruptured membranes (PRM) are poorly understood. Indicators predicting maternal and neonatal infectious morbidity do not correlate well with clinical outcomes. A previous report suggested that in vivo complement consumption occurred in response to the event of membrane rupture. In this prospective study, complement activity was measured serially throughout the latent period in cases of preterm PRM. In addition to total hemolytic complement activity (CH50), C4-pro-activator (C3PA), a primary component of the alternate complement pathway, was measured in maternal and cord sera. As with CH50, cord serum C3PA levels are significantly less than those in matched maternal samples. Neither maternal nor cord serum complement activity correlated with either the duration of the latent period or maternal-neonatal infection.

Bacterial Infections↗

Comparison of countercurrent immunoelectrophoretic assay with commercial radioimmunoassay kits for measuring prostatic acid phosphatase.

We evaluated and compared five commercial radioimmunoassay kits with a standard counter-immunoelectrophoretic assay for the measurement of prostatic acid phosphatase in serum. Four of the five radioimmunoassays performed as described by the supplier with respect to sensitivity, stability, precision, linearity, analytical recovery, and expected values for the normal male population. None of the radioimmunoassays was more clinically sensitive then the counter-immunoelectrophoretic assay for detecting increased prostatic acid phosphatase in serum. Results obtained by counter-immunoelectrophoretic assay agreed with results obtained by radioimmunoassay in 96% of the tests. The proportion of positive results in patients with confirmed prostatic adenocarcinoma increased with disease progression. The fewer positive tests in localized adenocarcinoma (Stages A and B) suggests that neither the counter-immunoelectrophoretic assay nor the radioimmunoassay procedures are useful for screening unselected populations for adenocarcinoma of the prostate. The high percentage of normal values found in those patients clinically free of disease after treatment is encouraging and supports the use of the prostatic acid phosphatase immunoassays in prospectively monitoring the treatment of prostatic cancer patients.

Acid Phosphatase↗

Counterimmunoelectrophoretic detection of a high incidence of precipitin reactions in normal human sera against staphylococcal teichoic acids and protein A.

The use of counterimmunoelectrophoresis (CIE) for detection of serum antibodies to staphylococcal teichoic acids was evaluated against teichoic acids prepared by sonic treatment or lysostaphin extraction of Staphylococcus aureus (Lafferty strain). Of 54 patient sera from suspected cases of staphylococcal endocarditis, osteomyelitis, or septicemia, 33 (61.1%) were positive by CIE analysis; however, 128 of 291 sera (44.0%) from normal adult donors were also positive. Selected CIE-positive sera from patient and control groups were titered by Ouchterlony gel diffusion. In the control group of normal sera, 65% were also positive by gel diffusion, but only 15% had titers of >/=1:2. Of the patient sera, 44.4% had gel diffusion titers of >/=1:2. In addition to the specific teichoic acid band, a second precipitation band could be demonstrated with both patient or normal sera by CIE or gel diffusion. This second precipitin band was shown to involve interactions of test sera with staphylococcal protein A present in the teichoic acid extracts. The protein A precipitins were detected at high concentrations of the antigen extracts, whereas the anti-teichoic acid precipitins were optimally detected at lower antigen concentrations. The formation of protein A precipitin bands did not correlate with the presence of anti-teichoic acid antibodies, as most sera tested were positive for protein A regardless of anti-teichoic acid activity. This study suggests that a high incidence of normal people have levels of antibodies to teichoic acids which are detectable by the highly sensitive, but nonspecific, technique of CIE.

Adult↗

Fate of human lactoferrin and myeloperoxidase in phagocytizing human neutrophils: effects of immunoglobulin G subclasses and immune complexes coated on latex beads.

Human neutrophils (PMN) degranulated in response to soluble human immune complexes and to myeloma proteins, including subclasses of immunoglobulin G (IgG)1, IgG2, IgG3, and IgG4 coated on 1.09-mum latex beads. Immunochemical measurement of lactoferrin (LF) from specific granules and myeloperoxidas (MPO) from azurophil granules showed that both classes of granule degranulated. Beads with soluble complexes of human anti-pigeon IgG-normal pigeon IgG, prepared from serum of a patient with pigeon breeders disease, induced significantly greater degranulation than did pigeon IgG-coated beads. Up to 40% of LF in the PMN degranulated during phagocytic challenge and 86% of that entered the extracellular fluid. Twenty to 30% of the MPO degranulated, but less than 50% of that entered the extracellular fluid. The degranulated LF and MPO which remained in the PMN were recovered from phagocytic vacuoles. Beads coated with purified human myeloma proteins (12 different ones, three of each subclass) induced degranulation in the order IgG3 greater than IgG1 greater than IgG2 greater than IgG4; however, these differences were found to be a function of the amount of latex ingested. Thus, the amount of degranulation was dependent more on the opsonizing capacity of the immunoglobulins rather than on their intrinsic capacities for inducing degranulation. Degranulation of both LF and MPO in response to IgG subclasses followed patterns similar to those caused by soluble immune complexes, and IgG3 coated on beads caused degranulation equal to that caused by human complex-coated beads. Degranulation to IgG3 and IgG4 was uninfluenced by fresh compared with heat-inactivated human AB serum. This was true although IgG3 beads fixed greater than sixfold more complement than did IgG4 beads. Evidently human IgG subclasses enhance phagocytosis and degranulation of human PMN. The overwhelmingly extracellular degranulation of LF in response to various bead coating suggest that it subserves a major protion of it role outside PMN.

Animals↗

Intracellular and extracellular degranulation of human polymorphonuclear azurophil and specific granules induced by immune complexes.

The nature of the phagocytic stimulus determines the degree of degranulation. Specifically, immune complexes induced more degranulation than did antigen or antibody alone. The release of constituents from the two granule classes represented independent phenomena. Relatively more of the specific granule proteins were released into the medium during phagocytosis, whereas more of the azurophil proteins were associated with the phagosomes.

Alkaline Phosphatase↗

Microbicidal activity of peroxidaseless chicken heterophile leukocytes.

Polymorphonuclear leukocytes (PMN) of the domestic chicken lack myeloperoxidase and, therefore, may be useful for studies of myeloperoxidase-independent antimicrobial mechanisms. Before such studies were undertaken, it was important to investigate the antimicrobial capacity of these cells against species of opportunistic pathogens that cause infection in humans with defective PMN function. In vitro, chicken PMN, like normal human PMN, readily phagocytized and killed Staphylococcus albus. They also killed Serratia marcescens, Escherichia coli, and Candida albicans. Cytochemical methods confirmed the absence of myeloperoxidase from chicken PMN.

Animals↗

Association of lactoferrin with lysozyme in granules of human polymorphonuclear leukocytes.

Lactoferrin is contained in cytoplasmic granules of human polymorphonuclear leukocytes. Upon centrifugation, it sediments in a band of granules that also contain 50% of the lysozyme activity. This granule class is distinct from others associated with alkaline phosphatase and peroxidase. The granules are latent for lactoferrin as only lysed granules have the capacity specifically to inhibit antigen binding by anti-lactoferrin serum.

Animals↗