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Biomedical subjects

M Hardy

Publications and source records attributed to M Hardy.

At least 91 records · Page 5Linked to original sources
PubMed1984

A comparison of the cyclic anhydride and mixed anhydride methods for 111In-DTPA chelation to monoclonal antibodies.

The cyclic anhydride (CA) and the mixed anhydride (MA) of DTPA were synthesized and used to chelate 111In to an antimelanoma monoclonal antibody. The CA and MA methods showed mean labeling efficiencies of 25.7 and 20.5%, respectively (p = NS). The binding efficiency of labeled antibody to human melanoma cells in tissue culture also was similar (means = 52 and 50%, respectively, p = NS), as was tumor uptake in nude mice at 96 hrs post-injection (16%-CA vs 12%-MA). The method required less complicated chemical syntheses, much less preparation time, and the product was stable over a much longer period. The results suggest that the CA method is preferable for bifunctional chelate labeling of monoclonal antibodies with 111In-DTPA.

Animals↗
PubMed1983

Evidence for triiodothyronine receptors in human endometrium and myometrium.

Thyroid gland dysfunction in humans may cause various female reproductive tract disorders. Thyroid hormone action is thought to be mediated by high-affinity low-capacity receptor proteins located in the nucleus. The studies detailed in this report were undertaken to determine if uterine nuclei contain specific high-affinity receptors for thyroid hormone. Nuclei from human endometrium and myometrium were prepared by homogenization and centrifugation following routine surgical procedures. With the use of isolated nuclei, binding experiments with 125I-triiodothyronine (T3) revealed a dissociation constant of approximately 1 X 10(-9) M in both endometrium and myometrium with a maximum number of binding sites equivalent to 0.06 and 0.21 pmol/mg of DNA, respectively. The solubilized binding sites were destroyed largely by trypsin treatment. Competition experiments revealed the following relative binding affinities for these nuclear binding sites: L-T3 greater than D-T3 greater than L-thyronine greater than reverse T3. These results indicate the presence in the human uterus of specific high-affinity binding sites with characteristics expected of a T3 receptor and thus raise the possibility that thyroid hormone may exert effects on the uterus through these receptors.

Binding Sites↗
PubMed1983

Immobilization of proteins on partially hydrolyzed agarose beads.

Treatment of agarose beads with mild acid (0.2 M HCl, 55 degrees C, several hours) hydrolyzes some of the glycosidic bonds between D-galactosyl residues and 3,6-anhydro-L-galactosyl residues, and thus produces aldehydo-groups useful for immobilization of amino compounds by reductive amination with NaCNBH3. More than 20 mg (0.3 mumol) of bovine serum albumin could be coupled per gram of partially hydrolyzed agarose beads. Arthrobacter neuraminidase immobilized by this method was useful for desialylation of sialyl glycoconjugates, and was found not to leach from the gel and to be much more thermostable than the free enzyme.

Animals↗
PubMed1983

Pancreatic polypeptide (PP) immunoreactivity in human parathyroid culture media.

Media from cultures of normal and abnormal human parathyroid fragments were assayed for parathyrin (PTH) and pancreatic polypeptide (PP) using sensitive radioimmunoassays. PP immunoreactivity was present in media (Day 6-7 in vitro) from cultures of 3/10 adenomas and 6/6 3 degrees hyperplastic glands (mean = 126. fmole/mg protein/day) (range = 6.-675.), and was not suppressed by 0 leads to 3 mM calcium challenge. PP was undetectable in media from cultures of one parathyroid carcinoma, one 1 degree hyperplasia, and one normal parathyroid. Medium C-terminal PTH levels were quite variable (26.-2,545,000. pg/mg protein/day). Presence of PP immunoreactivity in media from cultures of some hyperplastic parathyroids and some parathyroid adenomas suggests that PP may be released from these tissues in vitro. The significance of elevated PP levels in the MEA syndromes may be of special clinical relevance to this observation.

Adenoma↗
PubMed1983

Evidence for thyroid hormone receptors in uterine nuclei.

Nuclear preparations from the rat uterus contain specific, high affinity binding sites for T3, with the properties expected of a thyroid hormone receptor. The Kd value for the binding of T3 to these sites is 9.3 +/- 0.1 x 10(-10) M and the maximum number of binding sites is 0.11 +/- 0.02 pmoles T3 bound per mg of DNA. Competition experiments with Triac, D-T3, T4, and rT3 compared to L-T3 revealed relative affinities of 87%, 22%, 15%, and 1.6% respectively. T3 binding sites solubilized from uterine nuclear preparations by high salt extraction sediment at 3.6 S and are destroyed largely by trypsin treatment. Estradiol treatment of ovariectomized rats for 3 days did not alter the quantity of T3 binding sites expressed on the basis of DNA content. These results suggest that uterine nuclei contain a specific T3 receptor and raise the possibility that this hormone may have direct effects on the uterus.

Animals↗
PubMed1983

Peripheral nervous system myelin and Schwann cell glycoproteins: identification by lectin binding and partial purification of a peripheral nervous system myelin-specific 170,000 molecular weight glycoprotein.

Radioiodinated lectins were used to detect glycoproteins of peripheral nervous system (PNS) myelin (rat, human, bovine) and cultured rat Schwann cells. Proteins were resolved by sodium dodecyl sulfate-polyacrylamide slab gel electrophoresis and transferred to nitrocellulose filters. The filters were overlaid with radioiodinated lectins of known saccharide affinities. These included concanavalin A, Helix pomatia, Limulus polyphemus, Maclura pomifera, peanut, soybean, Ulex europaeus, and wheat germ agglutinins. Inclusion of the appropriate monosaccharide in the overlay solution (0.2 M) inhibited lectin binding to the nitrocellulose-fixed proteins. Fluorography permitted identification of 26 myelin glycoproteins and many more in Schwann cells. All lectins labeled a band present in myelin, but not Schwann cells, corresponding to the major PNS myelin protein, P0. Our attention focused on a high-molecular-weight myelin glycoprotein [apparent molecular weight (Mr) 170,000], which appeared abundant by Coomassie Blue staining and which was heavily labeled by all lectins except concanavalin A. A protein with approximately this Mr and lectin-binding pattern was present in human and bovine PNS myelin as well, but not detected in rat Schwann cells, CNS myelin, liver and fibroblast homogenates, or cultured bovine oligodendroglia. Hence this 170,000 Mr glycoprotein is apparently unique to PNS myelin.

Animals↗
PubMed1983

Antigenic modulation of pan-T-cell and T-cell subset-specific markers.

The time course and extent of antigenic modulation induced by monoclonal antibodies OKT3, OKT4, OKT8, BE2, and BE3 was investigated. OKT3-induced antigenic modulation could be detected as early as after 3-hr incubation with the antibody and almost total removal of the OKT3-reactive antigen was seen by 42 hr. This modulation did not decrease the expression of T-cell antigens detected by OKT4 and OKT8. OKT3-modulated cells reexpressed the antigen after 42-hr incubation in OKT3-free media. BE3 (homologue of OKT1) also caused modulation of its surface antigen after 24-hr incubation. In contrast, OKT4 did not induce modulation even after 42-hr incubation with high concentrations of OKT4 antibody. Approximately 43% of the OKT8-reactive lymphocytes could be induced to modulate this antigen. A tumor-associated antigen present on neoplastic lymphocytes from patients with cutaneous T-cell lymphoma, recognized by monoclonal antibody BE2, also was not induced to modulate. These results suggest that antigenic modulation and the fate of the modulated antibody may be of importance to immunotherapeutic applications of these reagents.

Animals↗
PubMed1983

[Identification and assay of nonvolatile organic by capillary column gas chromatography].

The assay of organic acids as trimethyl silyl isobutyl compounds by gas chromatography was described. The lyophilization was used instead the extraction by organic reagent of the classical methods. Our method avoids the loss of some hydroxylacids. The identification and the measurement of one organic acid need respectively 3 and 5 hours. Our method is currently used for the metabolic diseases diagnosis.

Carboxylic Acids↗
PubMed1982

Sensitization to low dose 5-fluorouracil. Subsequent enhancement of its systemic antitumor effect in the rat.

This report describes a novel method of immunochemotherapy; the active immunization to the drug 5-fluorouracil (5-FU) with enhanced antitumor activity resulting from its subsequent systemic administration. Two metastasizing carcinomas in the Fischer strain (F344) rat have been used: a chemically induced bladder carcinoma (FBCa) and a spontaneous mammary adenocarcinoma (MACa). Both tumors grow rapidly and result in 100% mortality within 10 wk of implantation. Neither tumor is sensitive to systemic 5-FU alone. Intradermal sensitization to 5-FU before FBCa tumor implantation, followed by 5-FU administered systemically, resulted in significant tumor regression and improvement in survival with eradication of all tumor and cure in 20% of animals. A similar antitumor effect was observed with the MACa. A comparable drug effect was observed when methotrexate sensitization was given before FBCa implantation followed by systemic MTX. Specificity to the sensitizing drug was demonstrated by the lack of effect of sensitization with either 5-FU or MTX unless followed by systemic therapy with the requisite sensitizing agent. Sensitization to 5-FU has also been assessed after FBCa implantation followed by resection of the local tumor. Resection was performed after distant tumor metastases had occurred, and was followed by systemic 5-FU therapy. Whereas tumor resection alone failed to cure any animal, sensitization to 5-FU increased cure rate fourfold over animals receiving systemic 5-FU alone. Antibody to 5-FU in the sera of sensitized animals has been suggested by an immunoenzymatic staining technique and its specificity confirmed in a radioimmunoassay. It is postulated that a combination of the systemic agent and the antibody elicited to it by sensitization produces the significant antitumor effect observed. The antitumor effect observed with this new approach to immunochemotherapy warrants further experimental and clinical study.

Animals↗
PubMed1982

Hormonal control of uterine growth: temporal relationships between estrogen administration and deoxyribonucleic acid synthesis.

Administration of a single injection of estradiol (E2) causes a maximum increase in DNA synthesis of all major uterine cell types approximately 24 h later. Animals given a second injection of E2 6-12 h after the first show an apparent increase in DNA synthesis in the luminal epithelium. Animals receiving a second injection of E2 15-18 h after the first show an apparent decrease in DNA synthesis at 24 h, which is most prominent in the luminal epithelium. This apparent decrease in DNA synthesis is most apparent if the second injection of E2 is given 18 h after the first, and is due to a shift of 10-12 h in the time course of DNA synthesis rather than to an absolute decrease in this parameter. This shift in the time course of uterine DNA synthesis is a dose-dependent phenomenon and displays a dose-response curve similar to that for the stimulation of DNA synthesis by a single injection of E2. A third injection of E2, 28 h after the initial hormone treatment, again causes a shift of 10-12 h in the time course of DNA synthesis relative to that in animals receiving two injections of hormone. These results suggest that nuclear levels of estrogen receptor, which initially increase after hormone administration, must decrease before the onset of uterine DNA synthesis.

Animals↗
PubMed1981

New HLA-D alleles associated with DR1 and DR2.

The present study describes two new HLA-D specificities : LD 13, associated with DR1, and LD14 associated with DR2. LD13 is defined by an HTC who is the bc offspring of an a: A25, B18, DR7, Dw7/b: A33, B14, DR1, Dx father, and of a c: A24, B14, Dr1, Dx/d: A26, B41, DR5, Dw5 mother. This HTC was included both as a responder and as a stimulator in our cross-reference studies of 8W HTCs. While failing to cluster with any other 8W HTC, it typed 2 of 64 panel members carrying a "blank" HLA-D, linked to DR1. To exclude the possibility that HTC-LD13 might be a split of Dwl, the entire family was tested with the Family Set of 8W HTCs. No typing responses to any 8W Dw1 HTCs were observed. Furthermore, checkerboard experiments between HTC-LD13 and 8WDw1 HTCs showed strong reciprocal stimulation. The LD13 specificity was only found in Ashkenazi Jews and may be in linkage disequilibrium with HLA-B14. LD14 is defined by three, SD different, HTCs deriving from the same family of Sicilian descent. The family was included in the 8th Workshop and each HTC was shown to have inherited DR2, MT1 from both parents. When tested as stimulators, on our HLA-D reference panel, these cells were clustered in a distinct group, LD14, associated with DR2. None of the 8W HTCs appeared to belong to this cluster. The antigen frequency of LD14 is 0.03.

Alleles↗
PubMed1981

Oligodendroglial glycerophospholipid synthesis: incorporation of radioactive precursors into ethanolamine glycerophospholipids by calf oligodendroglia prepared by a Percoll procedure and maintained in suspension culture.

Oligodendroglia prepared from minced calf cerebral white matter by trypsinization at pH 7.4, screening, and isosmotic Percoll (polyvinylpyrolidone-coated silica gel) density gradient centrifugation survived in culture on polylysine-coated glass, extending processes and maintaining phenotypic characteristics of oligodendroglia. In the present study, ethanolamine glycerophospholipid (EGP) metabolism of the freshly isolated cells was examined during short-term suspension culture by dual label time course and substrate concentration dependence experiments with [2-3H]glycerol and either [1,2-14C]ethanolamine or L-[U-14C]serine. Rates of incorporation of 3H from the glycerol and of 14C from the ethanolamine into EGP were constant for 14 h. In medium containing 3 mM-[1,2-14C]ethanolamine and 4.8 mM-[2-3H]glycerol, rates of incorporation of 14C and 3H into diacyl glycerophosphoethanolamine (diacyl GPE) were similar. Under the same conditions, 3H specific activities of alkylacyl GPE and alkenylacyl GPE were much lower than 14C specific activities, likely as a result of the loss of tritium during synthesis of these forms of EGP via dihydroxyacetone phosphate. L-[U-14C]serine was incorporated into serine glycerophospholipid (SGP) by base exchange rather than de novo synthesis. 14C from L-[U-14C]serine also appeared in EGP after an initial lag period of several hours. Methylation of oligodendroglial EGP to choline glycerophospholipid (CGP) was not detected.

Animals↗
PubMed1981

Stimulatory and inhibitory effects of estrogen and antiestrogen on uterine cell division.

Acute administration of 17 beta-estradiol or the antiestrogen nafoxidine to immature rats produces quantitatively similar responses in the uterine stroma and myometrium, although the responses to nafoxidine occur at slightly later times. Both the hormone and drug cause nuclear translocation of equivalent amounts of estrogen receptor in these two cell types, although receptor translocation is slower with nafoxidine, and nuclear receptor levels remain elevated for an extended time. Based upon labeling and mitotic indices, however, the response of the luminal epithelium to a maximum dose of nafoxidine is much lower than that produced by estradiol, although nafoxidine treatment causes massive hypertrophy of luminal epithelial cells and causes nuclear translocation of estrogen receptors in this cell type. If nafoxidine is administered 30 min after administration of estradiol, cell division in the luminal epithelium is inhibited. Furthermore, multiple injections of estradiol itself within a 24-h period decrease cell division in the luminal epithelium relative to controls receiving a single injection of the hormone. These results indicate that estradiol and the antiestrogen can have both inhibitory and stimulatory effects on the luminal epithelium and that cell division in different uterine cell types can be differentially affected.

Animals↗