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Biomedical subjects

R W Steele

Publications and source records attributed to R W Steele.

At least 145 records · Page 8Linked to original sources
PubMed1976

Acetylcholinesterase of the house-fly head. Affinity purification and subunit composition.

1. Acetylcholinesterase (acetylcholine hydrolase, EC 3.1.1.7) of house-fly head tissue was solubilized as a 7.4-S form by autolysis for 80-100 h at 25 degrees C and pH 8.0. 2. The autolysed enzyme was purified by affinity chromatography, firstly on Con-A-Sepharose and subsequently on m-trimethylammoniumaniline-Affi-Gel 202. This sequence permitted overall purification yields of approx. 50% of the solubilized enzyme. 3. The 7.4-S purified enzyme was essentially homogeneous on polyacrylamide gel electrophoresis, and its specific activity coincided with the highest previously reported for fly-head acetylcholinesterase. 4. Polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate and beta-mercaptoethanol revealed two major polypeptide components of molecular weight 82 000 and 59 000. Each of these polypeptides contained diisopropylphosphofluoridate-binding sites, as shown with [3H] diisopropylphosphofluoridate. 5. The results suggest a strong structural similarity between fly-head acetylcholinesterase and the purified electric eel enzyme.

Acetylcholinesterase↗
PubMed1976

Screening for cell-mediated immunity in children.

Skin testing and in vitro lymphocyte blastogenesis with Monilia and tetanus toxoid were examined as methods of screening cell-mediated immunity (CMI) in infants and children. With increasing age, all assays were more likely to be positive. Tetanus toxoid was a better single screening antigen than Monilia, particularly for young infants. Combining all assays, at least one was positive in 88% of children over 6 weeks of age. Combining the two skin tests, at least one was positive in 73% of children in the same age range. Results for the blastogenic assays indicated that this in vitro test is more sensitive than the in vivo skin test for demonstrating CMI to these two antigens. Infants with documented histories for Monilia diaper rash had a significantly higher probability of having a positive skin or blastogenic reaction with Monilia.

Age Factors↗
PubMed1976

Therapy for disseminated coccidioidomycosis with transfer factor from a related donor.

A 17 year old caucasian woman in whom disseminated coccidioidomycosis developed with culture positive meningitis during her third trimester of pregnancy was treated with amphotericin B and subsequently with transfer factor prepared from her father's peripheral lymphocytes. Clinical response and in vivo and in vitro immunologic data indicated that this transfer factor afforded a significant contribution to her survival whereas previous therapy with transfer factor from an unrelated donor provided only transient immunologic reactivity. This experience suggests that transfer factor prepared from a related donor with positive responses to C. immitis may be more efficacious than that prepared from an unrelated donor.

Adolescent↗
PubMed1976

Specific inhibitory factors of cellular immunity in children with subacute sclerosing panencephalitis.

Employing a 51Cr release cytotoxicity microassay, and using both measles-and SSPE-infected target cells, four patients with documented SSPE were evaluated for specific cellular and humoral immunity. Mononuclear leukocytes from SSPE patients and control subjects exhibited comparable cytotoxicity. Serum and CSF from these SSPE patients inhibited the cellular response to SSPE-infected cells but not to measles-infected cells. Moreover, fresh whole serum alone from control donors produced significant 51Cr release from both cell lines, whereas SSPE whole serum was effective only against measles-infected cells. CSF from an additional ten patients with SSPE was examined for inhibitory activity: seven of these completely blocked and one partially blocked cell-mediated cytotoxicity to SSPE-infected cells. Preliminary characterization of the serum inhibitory factor suggested that it is IgM or antigen-antibody complexes. These data also suggest antigenic differences between the SSPE and measles viruses.

Adolescent↗
PubMed1976

Skin test and blastogenic responses to Sporotrichun schenckii.

In vivo skin testing and in vitro lymphocyte blastogenesis were evaluated in a young adult population as methods for detecting cellular immunity to Sporotrichum schenckii. Similar procedures for Candida albicans and Coccidioides immitis were also investigated. 5 of 143 subjects had positive skin tests and 14 had positive blastogenic responses to S. schenckii. These 14 subjects also exhibited unusually high responses to C. albicans in vitro and 11 of the 14 were female. Data demonstrated a correlation coefficient of 0.89 when comparing the blastogenic assays for S. schenckii and C. albicans, suggesting cross antigenicity. Intact cellular immune mechanisms in combination with exposure to C. albicans may protect the host from systemic infection with S. schenckii. Although a limited number of subjects were studied, as a group, females had more vigorous cellular immune responses to C. albicans than males. The rare occurence of sporothrix infection in females as compared to males may be the result of antigenic stimulation from commonly observed vaginal colonization with C. albicans. The present data indirectly support this hypothesis.

Adolescent↗
PubMed1976

Severe combined immunodeficiency with cartilage-hair hypoplasa: in vitro response to thymosin and attempted reconstitution.

The present report describes an infant with severe combined immunodeficiency and cartilage-hair hypoplasia whose lymphocytes responded to thymosin in vitro. Immunologic evaluation was undertaken at 4 1/2 months of age following a history of recurrent severe infection. Family history included three cousins who died in early infancy, one from streptococcal meningitis and pneumonia, one from generalized varicella, and another from reticuloendotheliosis. Quantitative immunoglobulins were markedly depressed: IgG 141, IgA 0, and IgM 24 mg/100 ml. There was an absolute lymphopenia, multiple skin tests were negative, and in vitro lymphocyte responses to mitogens and antigens were depressed. Spontaneous E rosette determinations were 21% compared with control values of 65.7%. Erythrocyte adenosine deaminase (ADA) activity was normal. The patient's E rosette formation increased in the presence of thymosin, fraction 5, reaching a maximum of 56% with a concentration of 500 mug thymosin. Blastogenic responses to phytohemagglutinin also increased in the presence of thymosin. Transplantation of 24-week fetal thymus in Millipore diffusion chambers and subsequently transplantation of 18-week fetal thymus by intraperitoneal injection was accomplished. E rosettes increased to 35-40% and blastogenic responses to mitogens increased. Eight days after the second transplant the patient underwent a mild graft vs. host reaction which subsided after 1 week and mitogen blastogenic responses again increased to 5-8 times previous values, but still well below control ranges. Repeated episodes of pulmonary infection ensued, cor pulmonale resulted, and the clinical course was relentlessly downhill with the patient expiring from respiratory failure 5 months after transplantation.

Cartilage↗
PubMed1975

Cellular immune responses to Herpes simplex virus type 1 in recurrent herpes labialis: in vitro blastogenesis and cytotoxicity to infected cell line.

Cellular immunity to herpes simplex virus type 1 (HSV-1) in 12 volunteers with recurrent herpes labialis was evaluated by means of two microassays. In the blastogenesis assay, lymphocytes were incubated with tissue culture cells persistently infected with HSV-1. Uninfected cells were used as controls, and a blastogenic index was calculated. The mean blastogenic index (plus or minus SD) for subjects with recurrent herpes labialis was 26.9 (plus or minus 8.3); the mean blastogenic index (plus or minus SD) in control donors with antibody to HSV-1 was 13.4 (plus or minus 7.2). The difference between these values was statistically significant (t equals 4.154; P smaller than 0.001). In the cytotoxicity assay, cells of the same persistently infected line were used as target cells, and release of 51-Cr from these cells or from control cells served as the index of lymphocyte reactivity. Specific immune release attributable to HSV-1 averages 3.7% (plus or minus 1.8%) in subjects with recurrent herpes labialis, compared with 23.1% (plus or minus 9.8%) in controls (t equals 6.135; P smaller than 0.001). These data suggest a dissociation between mechanisms of cellular immunity, with enhanced lymphocyte blastogenesis but decreased cytotoxicity. Recurrent herpes labialis may thus result from subtle cellular immune deficiency involving at least one of the efferent mechanisms.

Adenoma↗
PubMed1975

Effects of adenine arabinoside on cellular immune mechanisms in humans.

In vitro lymphocyte blastogenic responses to the commonly employed mitogens, phytohemagglutinin, pokeweed, and concanavalin A, were evaluated when adenine arabinoside (ara-A) in a concentration of 3 mug/ml was added to the culture materials. Similarly, blastogenic and cytotoxic responses to cell cultures persistently infected with herpes simplex virus 1, herpes simplex virus 2, and varicella-zoster virus were determined in the presence of ara-A. No depression of these cellular immune responses by ara-A was demonstrated. This was in contrast to the effect of cytosine arabinoside, which at a concentration of 3 mug/ml severely inhibited these immune responses. Further studies examined lymphocyte blastogenic responses to the mitogens and blastogenic and cytotoxic responses specific for the herpes group virus infecting patients who were subsequently treated with ara-A; determinations were made before, during, and after treatment. In vitro responses during and after treatment with ara-A were unchanged or often enhanced as compared to pretreatment values. Therefore, the antiviral chemotherapeutic agent, ara-A, does not appear to depress the host's cellular immune responses, which are vital to successful elimination of invading herpes group viruses.

Humans↗
PubMed1974

Impaired cellular immunity to rubella virus in congenital rubella.

Specific cell-mediated immunity (CMI) responses to rubella virus were studied in 12 children with documented congenital rubella syndrome employing a (51)Cr lymphocytotoxicity microassay. Hemagglutination inhibition antibody was detected in 11 of the 12 children, with titers ranging from 1:4 to 1:128. CMI to rubella virus was demonstrated in only 3 of the 11 antibody-positive children. The 12th child was negative for both hemagglutination inhibition and CMI. Of the three children with a positive CMI response, two had histories of reinfection with rubella virus. These data suggest that congenital rubella infection produces an impaired CMI response which subsequently may be altered by reinfection with rubella virus. The lack of CMI in the presence of antibody and concurrent excretion of live virus in the child with documented congenital rubella infection suggest a factor to be explored in the pathogenesis of this disease.

Adolescent↗