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Biomedical subjects

R W Steele

Publications and source records attributed to R W Steele.

At least 127 records · Page 7Linked to original sources
PubMed1980

Transfer factor for the prevention of varicella-zoster infection in childhood leukemia.

Sixty-one patients with leukemia and no immunity to chickenpox were given dialyzable transfer factor or placebo and followed for 12 to 30 months in a double-blind trial designed to examine the clinical efficacy of transfer factor. Sixteen patients in the transfer-factor group and 15 in the placebo group were exposed to varicella zoster, and most of them had a rise in antibody titer. Chickenpox developed in 13 of 15 exposed patients in the placebo group but in only one of 16 in the transfer-factor group (P = 1.3 x 10(-5)). In the patients treated with transfer factor and exposed to varicella without acquiring chickenpox the titer of antibody to varicella zoster was equal to that in the patients given placebo who became infected with chickenpox. Transfer factor converted negative results on skin tests for varicella zoster to positive in approximately half the recipients. Passive immunization with dialyzable transfer factor appears useful in nonimmune persons.

Adolescent↗
PubMed1980

Breast-feeding and Salmonella infection.

Various assays were used to examine chemotaxis, opsonization, phagocytosis, and killing of Salmonella organisms by colostral and breast-milk components. Vigorous responses of colostral a;d milk cells against this organism and nonspecific opsonizing capacity of the aqueous phase of colostrum and milk were demonstrated. An assay with acridine orange was used to directly visualize the phagocytic and killing processes; colostral and milk cells were demonstrated to be more active against Salmonella than blood neutrophils. In a retrospective survey, a diagnosis of Salmonella infection was confirmed in 253 infants less then 1 year of age. Only 12 infants had ever been breast-fed, and only one near the time he had the disease. During the same period of time, 27% of matched control infants were breast-fed.

Breast Feeding↗
PubMed1980

Bactericidal mechanisms of human breast milk leukocytes.

The functional capacity of human breast milk phagocytes was evaluated with both bactericidal and biochemical assays. Acridine orange was used as a vital stain for bacteria to directly visualize phagocytosis and killing. Bactericidal capabilities were further examined by colony count and chemiluminescent methods. Cytocentrifuged specimens stained for myeloperoxidase exhibited enzyme activity in breast milk leukocytes equal to that of peripheral neutrophils. A radioisotopic assay of hexose monophosphate shunt activity demonstrated metabolic activity in breast milk leukocytes greater than that in peripheral blood neutrophils. However, the chemiluminescent response of breast cells was negligible, apparently the result of quenching secondary to fat present in the milk; preincubation of human blood leukocytes with the fatty layer of breast milk produced similar inhibition in the chemiluminescence assay. By most parameters breast milk phagocytes are at least equal to blood neutrophils.

Colostrum↗
PubMed1980

Comparative in vitro imunotoxicology of acyclovir and other antiviral agents.

In vitro lymphocyte blastogenic responses to the commonly employed mitogens phytohemagglutinin, pokeweed, and concanavalin A were evaluated when acyclovir, adenine arabinoside, cytosine arabinoside, and idoxuridine were added to the culture materials. Similarly, specific antigen-induced blastogenic responses, including herpes group antigens, and cytotoxicity and leukocyte inhibitory factor assays with herpes group viruses were determined in the presence and absence of antiviral agents. No depression of these cellular immmune responses by acyclovir or adenine arabinoside ws demonstrated. This was in contrast to the effects of cytosine arabinoside and idoxuridine, which severely inhibited blastogenic and cytotoxic responses but not leukocyte inhibitory factor production. Even at concentrations up to 20 microgram/ml, the antiviral agent acyclovir did not depress selected cellular immune responses that are important for successful elimination of invading herpes group viruses.

Acyclovir↗
PubMed1980

Recurrent staphylococcal infection in families.

This controlled double-blind study examined the efficacy of a single large inoculum of Staphylococcus aureus 502A in interrupting intrafamilial spread of recurrent staphylococcal abscesses. Forty families were enrolled in the study and 32 completed six months of follow-up care. All participants were first treated with oral oxacillin sodium or dicloxacillin sodium, twice daily hexachlorophene showers, and bacitracin given nasally for two weeks. Some then received nasal inoculation of 10(8) to 10(9) organisms of S aureus 502A while others were given only sterile broth. Fifteen of 17 families or 29 of 36 individuals who received 502A remained free of recurrence for six months of observation, while only four of 15 control families or 18 of 34 members had no recurrences (P less than .005). After six months after colonization, 83% of the treatment group retained the 502A organism.

Administration, Intranasal↗
PubMed1978

Transfer factor and its protective effect against herpesvirus infections of marmosets.

Using skin test response and lymphocyte blastogenesis as indicators of cell-mediated immunity, we have been able to demonstrate in vivo transfer of cell-mediated immunity to marmosets both with dialyzable transfer factor (TFd) prepared from a human donor and transfer factor (TF) from baboon whole cell lysates. We were able to protect marmosets with TFd from fatal Herpesvirus hominis type 1 (HVH-1) disease. When TFd was administered prior to challenge with HVH-1, 50% of the marmosets survived. Of the untreated control animals and those first treated on day 0 or postinfection, 100% succumbed to disseminated HVH-1 disease. In addition, when TF prepared from TFd-treated marmosets which had survived HVH-1 disease, was given to other marmosets, it conferred protection from subsequent HVH-1 challenge.

Animals↗
PubMed1977

Isoenzyme status and genetic variability of serum esterases in the lesser snow goose, Anser caerulescens caerulescens.

A maximum of 22 bands comprising four esterase subgroups--acetylesterase, carboxylesterase, cholinesterase, and acetylcholinesterase--were detected following electrophoresis of lesser snow goose sera on polyacrylamide gels. A minimum of seven structural genes was surmised to be involved in the biosynthesis of these enzymes following physiochemical characterizations. The genetic variability of these loci was calculated to be 1.25% average heterozygosity, while 14.3% of the loci were polymorphic. These estimates of genetic variability were substantially lower than those reported for other vertebrate species. The low degree of genetic variability found in snow goose serum esterases coupled with the extensive protein multiplicity observed may possibly reflect an adaptive strategy based on "biochemical plasticity" rather than genic heterozygosity for this species. The nature of evolutionary forces acting upon multiple enzyme systems such as esterases is discussed. The concept of "conditional neutrality" is introduced and defined within this context.

Animals↗
PubMed1977

Cellular immune responses to herpesviruses during treatment with adenine arabinoside.

Thirteen patients severely infected with herpesvirus were treated with intravenous adenine arabinoside (ara-A), and two patients received placebo therapy. Blastogenic and cytotoxic responses specific for the virus infecting each patient were determined before, during, and after treatment. Blastogenic responses to three mitogens (phytohemagglutinin, pokeweed, and concanavalin-A) were examined, as were titers of viral antibody. In vitro responses during and after treatment with ara-A were unchanged or often enhanced as compared with values before treatment. Newborn infants, presumably infected at or shortly before birth, did not demonstrate cellular immune reactivity to the infecting virus until after four days of life. In this series of patients, prognosis appeared to be in part determined by the cellular immune competence of the host at the time of infection.

Adolescent↗
PubMed1977

Correlation of mixed lymphocyte reactivity and skin graft rejection in nonhuman primates.

One-way mixed lymphocyte culture (MLC) reactivity and skin graft rejection were investigated to assess immune competence and histocompatibility in the baboon, the cebus monkey, and the cotton-topped marmoset. Adequate and comparable cell-mediated immunity was demonstrated. MLN reactions revealed strong histocompatibility differences among the three primate species and stimulating alloantigens for unrelated individuals of each species. Xenogeneic skin grafts survived nine days and allogeneic grafts, an average of 11 days. These systems appear readily applicable for assessing histocompatibility in nonhuman primates.

Animals↗
PubMed1977

E and EAC rosettes in man and nonhuman primates and the effect of thymosin in vitro.

E (erythrocyte) and EAC (erythrocytes coated with antibody and complement) rosettes were quantitated in baboons, cebus monkeys and cotton-topped marmosets. There was poor correlation between E rosette levels and other parameter of T-lymphocyte function. In nonhuman primates, E rosettes were increased in the presence of thymosin fraction V, while human E rosettes were not affected.

Animals↗
PubMed1976

Acetylcholinesterase from the house-fly head. Molecular properties of soluble forms.

1. Polyacrylamide gel electrophoresis in Tris/glycine buffer (pH 8.3) revealed five forms of acetylcholinesterase (acetylcholine hydrolase, EC 3.1.1.7) in the 100 000 X g, 1-h supernatants of aqueous fly-head extracts from the DDT/S strain. Five other housefly strains (CSMA, Bayer 21/199, Cradson/P, Malathion/R and DDT/R)were shown qualitatively to have the same soluble forms of the enzyme. 2. Plots of the electrophoretic mobility versus polyacrylamide concentration indicated that the multiple forms constituted a size isomer family. From the retardation coefficients derived from these plots, molecular weight estimates were obtained; these suggested that the smallest active component was a form of approx. 80 000 daltons. The higher aggregates, however, did not appear as simple oligomers of this component. 3. Density gradient sedimentation supported the electrophoretic findings. The smallest active component, with a sedimentation coefficient of 5.3 S, was confirmed as a molecular species of acetylcholinesterase that has not previously been obtained from house-flies; higher aggregates gave sedimentation coefficients of 7.4, 7.8. 8.1, and 11.8 S. 4. Gel-filtration on calibrated Sephadex G-150 columns provided further evidence that the smallest active component was a form of about 80 000 daltons. 5. Autolysis converted much of the particulate enzyme and all of the soluble forms into a species of approx. 160 000 daltons indistinguishable from the native 7.4-S form. Both the autolysed enzyme and the native 7.4-S form were susceptible to cleavage by disulphide reducing agents, and released catalytically active subunits that corresponded to the 5.3-S form of 80 000 daltons. The data were compatible with a monomer-dimer relationship between the 5.3-S and 7.4-S forms. 6. The possibility is suggested that a form of molecular weight approx. 80 000 constitutes the "fundamental unit" of insect cholinesterase.

Acetylcholinesterase↗