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Biomedical subjects

B A Phillips

Publications and source records attributed to B A Phillips.

82 records · Page 5Linked to original sources

Polypeptide composition of poliovirions, naturally occurring empty capsids, and 14S precursor particles.

The three serotypes of poliovirus were compared with respect to their polypeptide composition. Type 1, 2, and 3 strains were clearly different from each other in the electrophoretic mobilities of their larger structural polypeptides. Some of the viral polypeptides formerly identified as single peaks (e.g., VP 2) were shown to contain multiple components, indicating that purified virions contain at least six polypeptides. Three type 1 strains were indistinguishable in their viral polypeptides. A quantitative estimate was made of the polypeptide composition of the type 1 Mahoney poliovirion, as well as of naturally occurring empty capsids and 14S precursor particles. The data are discussed in light of the antigenic differences among polioviruses and the possible modes of virion morphogenesis.

Animals↗

Polyadenylic acid sequences in the virion RNA of poliovirus and Eastern Equine Encephalitis virus.

Poliovirus virion RNA contains a single covalently bound sequence of polyadenylic acid which is approximately 49 nucleotides long. A single, slightly longer polyadenylic acid sequence is contained in Eastern Equine Encephalitis virus RNA. Since these viruses are otherwise dissimilar these sequences may play a common role in viral replication, possibly in translation of the viral RNA.

Adenine Nucleotides↗

Premenstrual asthma: the effect of estrogen on symptoms, pulmonary function, and beta 2-receptors.

STUDY OBJECTIVES: To characterize asthma symptoms, pulmonary function, and responsiveness to beta 2-agonist stimulation, and in vitro beta 2-receptor density and cyclic adenosine 3',5'-monophosphate (cAMP) response throughout the menstrual cycle in women with premenstrual asthma (PMA); and to examine the effect of exogenous estradiol administration on asthma symptoms, pulmonary function and responsiveness, and beta 2-receptor density and function in these women. DESIGN: Open-label, longitudinal, 9-week study. SETTING: A university clinical research center. PATIENTS: Seventeen women with mild to moderate asthma, of whom 14 completed the study. INTERVENTIONS: Every morning on awakening during the entire 9-week study, each subject completed visual analog scales for asthma symptomatology (cough, wheezing, breathlessness, chest tightness) and measured and recorded her peak expiratory flow rate (PEFR) with a peak flow meter. Also measured at various times throughout the menstrual cycle were dyspnea index scores, pulmonary function (PEFR, forced expiratory volume in 1 sec [FEV1]), pulmonary response to subcutaneous terbutaline, T lymphocyte beta 2-receptor density (Bmax) and function (cAMP), and estradiol, progesterone, and catecholamine concentrations, both with and without exogenous estradiol administration. MEASUREMENTS AND MAIN RESULTS: At the time of enrollment, only 5 subjects reported premenstrual worsening of asthma symptoms, but all 14 had greater than 20% decrease in PEFR and/or increase in symptoms premenstrually during the study. Significant differences (p < 0.05) existed in asthma symptoms and PEFR between day 13 (highest estradiol concentrations) and day 26 (lowest estradiol concentrations) of the menstrual cycle. Asthma symptoms and dyspnea index scores were significantly improved (p < 0.05) after estradiol administration compared with baseline (premenstrual period without exogenous estrogen). Pulmonary response to terbutaline, beta 2-receptor density and function, and catecholamine concentrations were not significantly altered after estradiol administration, but the trend was toward significant differences (0.05 < p < 0.2) in pulmonary function tests (PEFR, FEV1). CONCLUSIONS: Even asthmatics not previously aware of PMA may experience premenstrual worsening of asthma symptoms and/or PEFR. Estradiol is associated with a significant improvement in asthma symptoms and dyspnea index scores. This ameliorating effect does not appear to be related to beta 2-receptors.

Adolescent↗