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Biomedical subjects

A C Ferguson

Publications and source records attributed to A C Ferguson.

51 records · Page 3Linked to original sources
PubMed1978

Prolonged impairment of cellular immunity in children with intrauterine growth retardation.

Cellular immunity was studied in 17 newborn infants, in eight children aged 1 to 5 years with intrauterine growth retardation, and in age-matched control subjects. At birth T and B peripheral blood lymphocytes were decreased, and delayed cutaneous hypersensitivity to phytohemagglutinin was diminished. In vitro PHA-induced lymphocyte proliferation was similar to that in control subjects but was greater than in healthy adults. In later childhood the numbers of T lymphocytes were normal, but their proliferative capacity was significantly reduced and cutaneous hypersensitivity was minimal or absent. Prolonged impairment of cellular immunity in these children may explain their increased susceptibility to infection and inadequate response to immunization, and predispose to the development of allergic, autoimmune, and neoplastic disease.

Aging↗
PubMed1977

Correlation of cutaneous hypersensitivity with lymphocytic response to Candida albicans.

The relationship between delayed cutaneous hypersensitivity to Candida albicans and in-vitro lymphocytic proliferative response using a highly sensitive micro-technic was studied in 26 healthy adult subjects and six children with chronic mucocutaneous candidiasis. The maximum in-vitro lymphocytic proliferative response in adult subjects with cutaneous hypersensitivity, 18.94 +/- 4.16 (SE), was significantly greater than that in those without cutaneous reactions, 2.49 +/- 0.45 (SE) (P less than 0.005). A close correlation was found between cutaneous hypersensitivity (mean diameter of induration at 48 hours) and in-vitro lymphocytic proliferative response (r = 0.73, P less than 0.001). A cutaneous reaction of 5 mm or more of induration after injection of 0.1 ml of 1:100 Candida albicans extract corresponded to an in-vitro lymphocytic proliferative index of 5 or more (P less than 0.005), which supports the previously empiric use of 5 mm of induration as an indicator of intact cellular immunity in clinical practice. In the children with chronic mucocutaneous candidiasis, no consistent relationship between cutaneous hypersensitivity and lymphocytic proliferative response was found. Administration of Levamisole resulted in increased lymphocytic proliferation in vitro, and the development of cutaneous hypersensitivity, suggesting potentiation of cellular immune function.

Adolescent↗
PubMed1977

Serotonin metabolism in cystic fibrosis.

The average blood serotonin level of 67 children with cystic fibrosis was found to be about twice that of age-matched normal children. There was no corresponding increase in the urinary excretion of 5-hydroxyindoleacetic acid (5-HIAA). Children with cystic fibrosis were well able to metabolize serotonin taken by mouth. No significant correlations were found between the blood serotonin level and the platelet count, height, weight, skinfold thickness, and pulmonary function test, 5 out of 44 patients had raised serum IgE levels, and their mean blood serotonin was higher than in those with normal IgE levels. No explanation for this emerged. Comparable findings (raised blood serotonin normal platelet count, normal urinary 5-HIAA) have been reported only in severe mental retardation. Further study of this phenomenon is warranted because (a) a raised blood serotonin level is sufficiently characteristic of cystic fibrosis to explore its use in diagnosis, and (b) it may help to explain the pathogenesis of cystic fibrosis and (c) the metabolism and function of serotonin.

Adolescent↗
PubMedDate not supplied

Quantifying videotaped activity patterns: video translation software and training methodologies.

Questionnaires and diaries, the current methods of human activity data collection, do not accurately capture the detail necessary to quantify exposure incurred through the dermal and non-dietary ingestion routes. Stanford University's Environmental Engineering and Science Program has developed methodologies and software (VideoTraq) for training video translators, determining inter-observer reliability, and translating videotaped micro-activity patterns into computer text files. VideoTraq output files contain duration, in seconds, for each combination of location, activity, and object contacted corresponding to the sequential micro-activities of a videotaped subject's contact boundary (e.g., left hand, right hand, mouth). Such output allows for detailed analyses of micro-activity data, including contact frequency and duration. When coupled with environmental concentrations, these data will allow for more accurate exposure assessments, particularly for the dermal and non-dietary ingestion exposure routes.

Activities of Daily Living↗
PubMedDate not supplied

Quantified dermal activity data from a four-child pilot field study.

Thirty-three hours of videotape collected in a 1993 pilot study were quantified, via a video translation software application, to obtain left and right hand activity data of four children of farmworkers. Reported here are the children's contact duration and frequency for each object in their environment, duration spent in each location and activity exertion level, and frequency distributions of object contact durations. The pilot study provided valuable information for evaluating and improving videotaping and videotape translation methodologies as a means of gathering activity information that can be used to refine dermal exposure estimates. Although a larger database of children's videotaped activities for different ages and populations is needed before generalizations can be made, the data presented here are the most detailed information to date for children's micro-level dermal activities.

Administration, Cutaneous↗