Search PubMed⌕ Search

Biomedical subjects

M S Miller

Publications and source records attributed to M S Miller.

At least 127 records · Page 7Linked to original sources
PubMed1981

The role of oligosaccharide in transport of egg yolk riboflavin-binding protein to the egg.

The carbohydrate portion of chicken egg yolk riboflavin-binding protein was examined to determine its role in the biological activity of the protein. Yolk RBP was found to contain 5--6 mannose, five galactose, 12 N-acetylglucosamine and four sialic acid residues. Specific modifications of the oligosaccharide moiety were performed which included removal of sialic acid by mild acid hydrolysis, oxidation of galactose by galactose oxidase, and removal of N-acetylglucosamine and galactose residues by a mixture of glycosidases from Aspergillus niger. All of the modified proteins retained the ability to bind riboflavin although their capacities were lower than that of native yolk RBP. Circular dichroism of the modified yolk RBP samples showed changes in the near ultraviolet, but molar ellipticities in the far ultraviolet displayed only minor variations indicating no gross structural changes. All samples cross-reacted with RBP-specific antiserum. The plasma half-life of 125I-labeled yolk RBP was 62 min. Each of the modified samples was cleared more rapidly from the blood than native yolk RBP. Removal of sialic acid decreased the half-life of yolk RBP by 31%, while the other modifications decreased the half-life by as much as 60%. During a 10-day period following injection of 125I-labeled yolk RBP, 5.9% of the labeled protein was recovered from egg yolk. Relative to native yolk RBP, the transport of asialo-yolk RBP was decreased by 82%. The other modifications resulted in even less transport to the egg, the lowest being glycosidase-treated asialo-yolk RBP which was decreased by over 99%. By comparison of samples with similar clearance times, a positive correlation was made between sialic acid and ovarian transport.

Animals↗
PubMed1981

Thiamin deposition in eggs is not dependent on riboflavin-binding protein.

The thiamin content of eggs laid by hens possessing no, one or two functional genes for riboflavin-binding protein is unaffected by the genotype. This does not support the hypothesis of Muniyappa & Adiga [Biochem. J. (1979) 177, 887-894] that the deposition of thiamin-binding protein is coupled to the deposition of riboflavin-binding protein.

Animals↗
PubMed1981

Accurate measurement of intestinal transit in the rat.

A new method for quantifying intestinal transit was evaluated by comparison with two other popular techniques. The distribution of radiochromium (51Cr) throughout the small intestine of rats previously treated with saline (1.0 ml/kg s.c.), capsaicin (10 mg/kg s.c.), hexamethonium (20 mg/kg i.p.), D-ala2-met-enkephalinamide (1.0 microgram i.c.v.), or neostigmine (0.1 mg/kg i.p.) was quantified by (1) measuring the most distal intestinal segment reached by chromium, (2) calculating the slope produced by linear regression analysis on cumulative percent chromium that had passed through each segment, and (3) determining the geometric center of the distribution of chromium throughout the small intestine. It was concluded that the geometric center methods for quantifying intestinal transit provides the most sensitive and reliable measure of intestinal transit. Less sensitive techniques often fail to detect important effects of drugs on intestinal transit.

Analysis of Variance↗
PubMed1980

The purification and partial characterization of human somatomedin C.

Somatomedin C was purified from a Cohn IV fraction of human plasma by acid release followed by dialysis, ultrafiltration, Sephadex G-50 chromatography, and isoelectric focusing between pH 7 to 11. The resulting preparation, which focused at pH 8.6, was essentially free of insulin contamination and appeared homogeneous by acid gel chromatography and sodium dodecyl sulfate gel electrophoresis. The somatomedin C was purified about one-half-million-fold with a yield of 7%. The purified preparation had an apparent molecular weight of 7,400 with no indication of intermolecular disulfide bonds. Its amino acid composition revealed a lysine-rich peptide containing significant amounts of histidine and methionine. No free sulfhydryl was found. It stimulated in vitro cartilage sulfation and DNA synthesis of hypophysectomized rats. In the presence of hypopituitary serum, it increased cartilage sulfation of embryonic chick. Somatomedin C competed potentially with [125I]iodoinsulin for insulin receptors on human placenta cell membranes. [125I]Iodosomatomedin C apparently binds preferentialy to a high affinity placental receptor which is different from the insulin receptor.

Amino Acids↗
PubMed1980

Disposition of enflurane in obese patients.

The disposition of enflurane, a volatile halogenated anesthetic, was studied in obese (n = 26) and nonobese (n = 8) consenting adult subjects undergoing elective intra-abdominal surgical procedures. Enflurane and fluoride ion, a nephrotoxic metabolite of enflurane, were measured in the blood of subjects before, during and up to 24 hr after exposure to pharmacologically equivalent doses of enflurane [approximately 2.0 MAC hr (the minimal alveolar concentration at which 50% of humans do not respond to a painful stimulus)] Arterial enflurane in obese subjects reached maximal concentrations 3 times faster than nonobese subjects who reached similar blood levels 80 min after the initiation of anesthesia. The blood/gas partition coefficient for enflurane in the obese was found to be 30% lower than that in the nonobese (0.99 +/- 0.02 vs. 1.42 +/- 0.02) and may possibly explain the observed differences in enflurane uptake. The rate at which inorganic fluoride appeared in obese serum (5.5 microM/hr) was twice that seen in the nonobese group. No differences in urinary fluoride excretion were demonstrated. Maximum serum fluoride concentration occurred 2 hr postenflurane anesthesia in both groups with the obese having a 60% higher concentration (27.8 +/- 2.0 vs. 17.0 +/- 3.0 microM), indicating increased biotransformation in the obese. Hepatic triglyceride content was demonstrated to be unrelated to the increased enflurane biotransformation observed in obese subjects. Equations are presented for the estimation of mean maximum serum inorganic fluoride levels in both obese and nonobese subjects after enflurane anesthesia.

Biotransformation↗
PubMed1979

A rapid, sensitive method for quantifying enflurane in whole blood.

Thermal conductively detection (TCD) in conjunction with gas-liquid chromatography was employed for the analysis of enflurane in n-heptane extracts of whole blood. Enflurane was estimated to be 98 per cent extracted from whole blood by n-heptane. Analysis of enflurane standards ranging in concentration from 4.1 to 813 muM demonstrated linearity, with a correlation coefficient of 0.9999. As little as 8 muM enflurane may be detected in whole blood. TCD gas-liquid chromatography is a rapid and sensitive method for quantifying enflurane in whole blood.

Chromatography, Gas↗
PubMed1978

Stimulation of human fibroblast protein, ribonucleic acid, and deoxyribonucleic acid synthesis by bovine growth hormone fragments.

Bovine GH and two fragments which were obtained by dissociation of a limited tryptic digest of the hormone stimulated protein, RNA, and DNA synthesis of contact-inhibited human fibroblasts. The stimulation of protein, RNA, and DNA synthesis was similar for the test substances. Maximal stimulation was noted at 10 nM. At that concentration, protein, RNA, and DNA synthesis were respectively increased 1.80, 1.42, and 1.37 times by GH; 1.93, 1.27, and 1.46 times by A-I (the larger fragment); and 1.99, 1.26, and 1.33 times by A-II (the smaller fragment). The action of GH, A-I, and A-II was similar to that of fetal calf serum, but was distinguished by the time course of stimulation and by the magnitude of the response. For example, GH, A-I, and A-II produced their earliest detectable effect at 10 h for protein synthesis, 22 h for RNA synthesis, and 26 h for DNA synthesis. On the other hand, serum stimulated protein, RNA, and DNA synthesis at 6, 10, and 16 h, respectively. These data show that human fibroblasts respond equally to GH, A-I, and A-II and suggest that there may be more than one "active site" in the GH molecule. Lastly, human fibroblasts may represent a useful system to study the actions of GH in vitro.

Animals↗
PubMed1977

Cardiac contusion and right bundle branch block.

In a case of transient right bundle branch block due to nonpenetrating chest trauma, this abnormal electrocardiographic finding was the sole manifestation of cardiac contusion. There is a high frequency of occult cardiac contusion and routine electrocardiography is recommended in the evaluation of nonpenetrating chest trauma.

Adult↗
PubMed1976

Familial colon cancer.

Study was made of a kindred with a strong history of carcinoma of the colon. Twenty-three family members were screened for the tumor with carcinoembryonic antigen (CEA) assay, barium enema, and proctoscopy; one occult colon cancer was diagnosed. Identification and surveillance of families at high colon cancer was diagnosed. Identification and surveillance of families at high risk of cancer can provide unusual opportunities for early tumor detection.

Adenocarcinoma↗
PubMed1975

Amino acid and sugar transport incells permissively infected with simian virus 40.

Transport of alpha-aminoisobutyric acid and 2-deoxy-D-glucose in African green monkey kidney cells was measured 8 to 100 hr following permissive simian virus 40 infection. No differences in transport were detected during the time-period studies, and no significant differences were seen between the apparent Michaelis-Menten constants of normal and virally infected cells. The absence of transport enhancement in permissive simian virus 40 infection suggests that the augmented transport of viral-transformed cell lines devolves upon altered host genome function.

Aminobutyrates↗