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Biomedical subjects

M Phillips

Publications and source records attributed to M Phillips.

At least 325 records · Page 18Linked to original sources
PubMed1980

An improved adhesive patch for long-term collection of sweat.

An improved adhesive patch is described, capable of collecting sweat continuously at a steady rate for periods up to ten days. Four normal subjects wore duplicate patches applied to the skin above the outer ankle and the collecting pads were weighed every second day for ten days. Uptake was linear in all patches (r2 = 0.99) and the uptake rate varied from 18.38 to 47.01 mg/day (mean = 27.18 mg/day, equivalent to 0.71 mg/cm2/hour). Several drugs are excreted in the sweat, and this patch has potential applications as a tool to monitor drug-taking behavior.

Adhesiveness↗
PubMed1979

Diazepam kinetics in acute alcohol withdrawal.

We performed a within-subject comparison of the kinetics of diazepam given to 7 alcoholic subjects during acute alcohol withdrawal and again after detoxification. The initial rapid exponential decline of plasma diazepam concentrations (t1/2 alpha) was more rapid during (0.21 +/- 0.03 hr) than after withdrawal (0.44 +/- 0.14 hr, p less than 0.05). Terminal t1/2, clearance, and volumes of distribution changed in individual patients, but mean values did not change. Protein binding was less in patients (93.4 +/- 2.4%) than in healthy controls (97.0 +/- 1.0, p less than 0.05). The effects of alcohol withdrawal on diazepam disposition do not explain the high doses of diazepam commonly required to treat the withdrawal.

Adult↗
PubMed1979

Isolation and purification of bovine IgM by dissociating immunoglobulin-brucella complexes.

Methods for the dissociation of immunoglobulin-Brucella complexes (IgM-rich) were evaluated. The antigen-antibody complex was separated from serum by centrifugation and dissociated with either H2O, 2.0 M pH 2.0 glycine buffer, or various concentrations of KSCN. Optimal antibody recoveries for KSCN were obtained using 1.0--2.0 M KSCN. Dissociation of the complex with water resulted in the highest recovery of antibody and the glycine buffer was lowest. Immunoelectrophoretic analysis of the eluted antibody revealed the presence of IgG and IgM. At concentrations of KSCN greater than 2.5 M, albumin-like protein was also eluted from the antibody-antigen complex. The IgM could readily be separated from IgG and albumin by gel filtration. Purified IgM was Brucella specific, monodisperse, and had a sedimentation coefficient of 20.0.

Animals↗
PubMed1979

Processing of common precursor forms of adrenocorticotropin and endorphins in cultures of mouse pituitary cells and in mouse pituitary.

The initial steps in the processing of the common precursor to adrenocorticotropin (ACTH) and beta-lipotropin (beta-LPH) in mouse pituitary cells (AtT-20) have been investigated. Three forms of the precursor have been resolved by sodium dodecyl sulfate (NaDodSO4) polyacrylamide gel electrophoresis with apparent molecular weights of 29,000, 32,000 and 34,000 (29K, 32K, and 34K ACTH-endorphin). The three precursor forms have a very similar peptide backbone, but their carbohydrate content differs. In particular, a tryptic glycopeptide has been observed in 32K ACTH-endorphin which is not present in 29K ACTH-endorphin and has been identified as a tryptic peptide containing the alpha(22--39) sequence of ACTH. Pulse chase and continuous-labeling studies with radioactive amino acids and sugars suggest that the 29K form is converted to the 32K and 34K forms of the precursor by the addition of carbohydrate. The glycopeptide and pulse chase studies suggest that 29K ACTH-endorphin can either be converted to 4.5K ACTH by proteolytic processing or to 32K ACTH-endorphin by the further addition of carbohydrate.

Adrenocorticotropic Hormone↗
PubMed1978

Home blood sampling for plasma glucose assay in control of diabetes.

Estimation of plasma glucose in home blood samples is needed to improve diabetic control. Sufficiently precise measurements on capillary blood were obtained by (a) storing Reflotest glucose-oxidase strips in a desiccant container before reading and (b) collecting blood samples into a simple vacuum bottle containing potassium fluoride (assay of sodium content indicating volume of plasma collected). The precision of the methods (+/- 1 SD) was +/-0.35 mmol/1 (+/-6.3 mg/100 ml). Clinical reliability was assessed by measuring the basal plasma glucose concentration at home on different mornings in patients with maturity-onset diabetes, the day-to-day variation (+/- 1 SD) being +/-0.73 and +/-0.92 mmol/1 (+/-13.2 and +/-16.6 mg/100 ml) respectively. The mean basal plasma glucose concentration in all 84 patients with maturity-onset diabetes from three general practices was 8 mmol/1 (144 mg/100 ml), 44 of the values exceeding 6 mmol/1 (108 mg/100 ml). Improving control by monitoring the basal plasma glucose concentration in maturity-onset diabetes might help to prevent diabetic complications.

Aged↗
PubMed1978

Steps involved in the processing of common precursor forms of adrenocorticotropin and endorphin in cultures of mouse pituitary cells.

The initial steps in the processing of the common precursor to adrenocorticotropin (ACTH) and endorphin in mouse pituitary tumor cells (AtT-20) have been investigated. Three forms of the precursor have been resolved by sodium dodecyl sulfate (NaDodSO4)-polyacrylamide gel electrophoresis with apparent molecular weights of 29 000 (29K ACTH-endorphin), 32 000 (32K ACTH-endorphin) and 34 000 (34K ACTH-endorphin). These forms have a similar peptide backbone, but their carbohydrate content differs. In particular, a tryptic glycopeptide has been observed in 32K ACTH-endorphin which is not present in 29K ACTH-endorphin and has been identified as the tryptic peptide containing the alpha(22--39) sequence of ACTH. Similar heterogeneity in carbohydrate has been observed in some of the smaller molecular weight forms of ACTH which are resolved by NaDodSO4 gel electrophoresis. Pulse chase and continuous labeling studies using radioactive amino acids and sugars suggest that the 29K ACTH-endorphin is converted to 32K and 34K ACTH-endorphin by the addition of carbohydrate. The glycopeptide and pulse chase studies suggest that 29K ACTH-endorphin is at a branch point in the processing pathways. It can either be converted to 4.5K ACTH by proteolytic processing or to 32K ACTH-endorphin by the further addition of carbohydrate. The 32K ACTH-endorphin can then be converted to 13K ACTH, the glycosylated form of 4.5K ACTH (Eipper, B.A., & Mains,, R.E. (1977) J.Biol. Chem.252, 882), by proteolytic processing. A comparison of the distribution of the different molecular weight forms of ACTH and endorphin in mouse pituitary extracts and in the mouse pituitary tumor cells reveals that the pituitary contains all of the forms of ACTH and endorphin seen in the tumor cells, including the three forms of the ACTH-endorphin precursor. However, the molecular weight distribution of the forms in the anterior lobe is very different from that in the intermediate lobe of mouse pituitary.

Adrenocorticotropic Hormone↗
PubMed1978

The mucosa-associated microflora of the rat intestine: a study of normal distribution and magnesium sulphate induced diarrhoea.

Specimens of intestinal mucosa of rats were examined closely to determine the distribution of the mucosa-associated microbial flora. Six distinct zones were found along the length of the intestinal tract. The first zone, in the small intestine 50 cm or more from the ileocaecal junction, had no associated flora: however, each of the five other zones had different populations of microorganisms associated with the mucosa. Some of these organisms have not been reposted previously. Treatment of rats with oral doses of the purgative magnesium sulphate resulted in dramatic changes in the distribution of these mucosa-associated microorganisms. The normal flora of ileal and caecal crypts disappeared, while the organisms in colonic crypts were unchanged. Large numbers of mucosa-associated bacteria appeared in the stools of treated animals.

Animals↗
PubMed1978

Isolation of a precipitating glycoprotein antigen from cell cultures persistently infected with bovine leukemia virus.

A procedure was developed to isolate a glycoprotein with precipitating antigen activity from fluids from fetal lamb kidney cell cultures persistently infected with bovine leukemia virus (BLV). The antigen was precipitated by ammonium sulfate and subjected to affinity chromatography on concanavalin A Sepharose. The glycoprotein was eluted with alpha-methyl-D-mannoside and was further purified by gel filtration over Sephadex G-100. Antigen activity was determined by agar gel immunodiffusion (AGID) reactions with serum from cattle infected with the virus. The major portion of the AGID activity was eluted from the Sephadex G-100 in the 60,000-dalton elution region. In some experiments, identical AGID activity was also found in the 18,000-dalton elution region. The larger protein was discovered to have a molecular weight of 58,000 daltons by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Its designation as a glycoprotein was confirmed by carbohydrate-positive staining. The isolated BLV glycoprotein antigen did not contain ovine or bovine proteins as indicated by gel immunodiffusion.

Antigens, Viral↗