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Biomedical subjects

I Stewart

Publications and source records attributed to I Stewart.

At least 109 records · Page 6Linked to original sources
PubMed1977

The structure and differentiation of granulated metrial gland cells of the pregnant mouse uterus.

A study was made with the light and electron microscopes of the granulated metrial gland cells of the decidua basalis of the pregnant mouse uterus, up to day 11 of pregnancy. The granulated metrial gland cells are large, up to 50 mu in diameter, mono- or binucleate and the glycogen rich cytoplasm typically contains many large glycoprotein granules which may be up to 5 mu in diameter. Morphological evidence is described in support of a lymphocyte-like cell being the precursor to the granulated metrial gland cell. This differentiation sequence is similar to that already proposed in the rat but differences between the ultrastructure of the mature metrial gland cells of rats and mice were noted.

Animals↗
PubMed1977

High performance liquid chromatographic determination of provitamin A in orange juice.

A quantitative method has been developed for the determination of alpha- and beta-carotenes and beta-cryptoxanthin, the provitamin A carotenoids in orange juice. The carotenoids were separated by high performance liquid chromatography on a single column in approximately 30 min. The procedure may also be used to measure zeta-carotene and alpha-cryptoxanthin.

Beverages↗
PubMed1976

Specific removal of DNA antibodies in vivo with an extracorporeal immuno-adsorbent.

The selective removal of circulating antibody specific for DNA was affected with an immuno-absorbent consisting of DNA-cellulose incorporated into agar gel. Antisera to DNA obtained from patient with systemic lupus erythematosus was circulated in vitro through experimental and control columns by a dual channel haemodialysis pump and serial aliquots were withdrawn and assayed for antibody. A 65% reduction in DNA binding of serum was achieved at a flow rate of 210 ml/min over a 4-hr period with no release of 125I-labelled DNA from the column into the serum. For in vivo studies, 2-6-3-8 kg rabbits were actively immunized with methylated bovine serum albumin conjugated to single-stranded DNA (MBSA-ssDNA). Whole blood was pumped from the femoral artery through an immuno-adsorbent composed of ssDNA-cellulose in an agar matrix. Results showed significant reductions in ssDNA binding activity over various periods after connection of the rabbit's circulation to the immuno-adsorbent with only minimal changes in BSA binding during the same period. Little release of incorporated 125I-labelled DNA from the column as assayed in the blood and tissues of the experimental animals occurred during the procedure. The immuno-adsorbent columns showed no residual cellular debris or thrombotic material. These results suggest that this immuno-adsorbent system may be used to specifically withdraw circulating DNA antibodies in vivo. Such a system may have clinical potential for specific therapy of systemic lupus erythematosus.

Adsorption↗
PubMed1975

Localization of neuroblastoma in vivo with tumor-specific antibodies.

Studies of the mouse C-1300 neuroblastoma were undertaken in order to isolate tumor-specific antibodies and harness them for detection of tumors in vivo. Preliminary investigations demonstrated the strain-growth specificity of the neuroblastoma in A/Jax male mice and established the requirement for tumor viability for successful adoptive passage. Intradermally passaged tumor permitted extended survival of mice so that serum could be sampled at intervals for the presence of tumor-specific antibodies. By means of an indirect radioimmunoassay with glutaraldehyde-fixed identified in the serum of tumor-bearing hosts 6 days after inoculation, with a steady increase in antibody levels observed through Day 22. An eluate in which immunoglobulin G antibodies were identified by immunoelectrophoresis was obtained from purified tumor cells by acid buffer incubation. These antibodies were labeled with 125-I, absorbed with normal tissues, and injected into tumor-bearing mice. A selectively collimated single-probe isotope localization was positioned over the intradermal tumor, while the rest of the animal was shielded with lead. With this device, 125-neuroblastoma eluate was significantly taken up in the neuroblastoma but not in the mouse head or in a reticulum cell sarcoma control. Increasing uptake of MOPC 141 125-I-immunoglobulin G was not observed in either tumor. These studies suggest that the mouse neuroblastoma may provide a source of tumor-specific, antibodies and that, with sensitive monitoring devices, these antibodies may be utilized to localize occult neoplastic tissue in vivo.

Animals↗
PubMedDate not supplied

The killing of mouse trophoblast cells by granulated metrial gland cells in vitro.

Mouse placental cell preparations have been maintained in culture, and the types of cell that attached to the culture dish were classified according to morphological criteria. However, these morphological criteria were insufficient to determine from which trophoblast layer in the placenta all of the types of cell found in the cultures originated. Some placental cell preparations were co-cultured with granulated metrial gland (GMG) cells and these cultures were studied using time-lapse video. Various responses to contacts between GMG cells and trophoblast cells were observed. These responses included the killing of trophoblast cells by GMG cells.

Animals↗
PubMedDate not supplied

Monolith.

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Journal Article↗
PubMedDate not supplied

The magic of seven.

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Magic↗
PubMedDate not supplied

Phosphorus in fresh and dry dung of grazing dairy cattle, deer, and sheep: sequential fraction and phosphorus-31 nuclear magnetic resonance analyses.

Knowledge of phosphorus (P) fractions in dung of animals (dairy cattle, deer, sheep) grazing pasture is important for soil fertility and the potential for P transport in runoff and subsequent surface water quality deterioration. We used sequential fractionation and 31P nuclear magnetic resonance (NMR) spectroscopy to determine P forms in fresh and air-dried (to simulate field conditions during grazing) dung. Sheep dung was richest in P (8 g kg(-1)), and cattle dung poorest (5.5 g kg(-1)). Data for sequential fractionation indicated that most P was extractable by water (15-36%) and bicarbonate (36-45%) in fresh dung, and shifted toward recalcitrant, HCl (12-28%), and residual P forms (15-31%) with drying. Organic P concentration in dung was poor (maximum of 15% of total P), probably due to the poor concentration of phytate in pasture. The 31P NMR spectra of NaOH-EDTA extracts supported this by detecting a low concentration of monoesters (9-19% of total P in extracts), of which phytate is a major component. The 31P NMR data also showed that changes in organic P concentration with drying could be due to the degradation of diesters. Data indicate the decreasing bioavailability of dairy cattle, deer, and sheep dung with drying and the need to consider this effect with respect to P returns for soil fertility and the potential for runoff.

Animals↗