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Biomedical subjects

T Moody

Publications and source records attributed to T Moody.

At least 19 recordsLinked to original sources
PubMed2000

Expression of proadrenomedullin derived peptides in the mammalian pituitary: co-localization of follicle stimulating hormone and proadrenomedullin N-20 terminal peptide-like peptide in the same secretory granules of the gonadotropes.

Expression of proadrenomedullin-derived peptides in the rat, cow and human pituitary was studied by a variety of techniques. Immunocytochemical detection showed a widespread expression of adrenomedullin peptide in the adenohypophysis and the neural lobe, with low expression in the intermediate pituitary. Proadrenomedullin N-20 terminal peptide (PAMP)-immunoreactivity was also present in the anterior pituitary but showed a more marked heterogeneous distribution, with cells going from very strong to negative immunostaining. Lower levels of PAMP were found in the neural lobe. Interestingly, the distribution of adrenomedullin and PAMP immunoreactivity in the anterior pituitary did not completely overlap. In the present study, we concentrated our efforts to determine which cell type of the adenohypophysis expresses PAMP. Paraffin and semithin serial sections immunostained for PAMP and the classical pituitary hormones revealed that a subpopulation of the gonadotropes expresses high levels of PAMP-immunoreactive material. Ultrastructural analysis clearly showed PAMP-immunoreactivity in the follicle stimulating hormone (FSH)-containing large secretory granules of the gonadotropes, suggesting simultaneous secretion of PAMP and FSH by this cell type. Three mouse adenohypophysis-derived cell lines (AtT20, GH3, and alphaT3-1 derived from corticotropes, lacto/somatotropes and gonadotropes, respectively) were also analysed and showed expression of both proadrenomedullin-derived peptides and their mRNA. Functional studies in these three cell lines showed that neither adrenomedullin nor PAMP was able to stimulate cAMP production in our experimental conditions. Taken together, our results support that proadrenomedullin derived peptides are expressed in the pituitary in cell-specific and not overlapping patterns, that could be explained by differences in postranslational processing. Our data showing costorage of PAMP and FSH in the same secretory granules open a way by which PAMP could be involved in the control of reproductive physiology in a coordinated manner with FSH.

Adrenomedullin↗
PubMed1999

Targeting sigma receptor-binding benzamides as in vivo diagnostic and therapeutic agents for human prostate tumors.

Sigma receptors are known to be expressed in a variety of human tumor cells, including breast, neural, and melanoma tumors. A very high density (1.0-1.5 million receptors/cell) of sigma receptors was also reported in a human androgen-dependent prostate tumor cell line (LNCaP). In this study, we show that a very high density of sigma receptors is also expressed in an androgen-independent human prostate tumor cell line (DU-145). Pharmacological binding studies using the sigma-1-selective ligand [3H](+)-pentazocine showed a high-affinity binding (Kd = 5.80 nM, Bmax = 1800 fmol/mg protein). Similarly, binding studies with [3H]1,3-di-o-tolylguanidine in the presence of dextrallorphan also showed a high-affinity binding (Kd = 15.71 nM, Bmax = 1930 fmol/mg protein). Radioiodinated benzamide N-[2-(1'-piperidinyl)ethyl]-3-[125I]iodo-4-methoxybenzamide ([125I]PIMBA) was also shown to bind DU-145 cells in a dose-dependent manner. Three different radioiodinated benzamides, [125I]PIMBA, 4-[125I]iodo-N-[2-(1'-piperidinyl)ethyl]benzamide, and 2-[125I]-N-(N-benzylpiperidin-4-yl)-2-iodobenzamide, were screened for their potential to image human prostate tumors in nude mice bearing human prostate cells (DU-145) xenografts. All three compounds showed a fast clearance from the blood pool and a high uptake and retention in the tumor. Therapeutic potential of nonradioactive PIMBA was studied using in vitro colonogenic assays. A dose-dependent inhibition of cell colony formation was found in two different human prostate cells. These results demonstrate the potential use of sigma receptor binding ligands in non-invasive diagnostic imaging of prostate cancer and its treatment.

Animals↗
PubMed1996

Growth control of lung cancer by interruption of 5-lipoxygenase-mediated growth factor signaling.

Signal transduction pathways shared by different autocrine growth factors may provide an efficient approach to accomplish clinically significant control of lung cancer growth. In this study, we demonstrate that two autocrine growth factors activate 5-lipoxygenase action of the arachidonic acid metabolic pathway in lung cancer cell lines. Both growth factors increased the production of 5(S)-hydrooxyeicosa-6E,8Z,11Z,14Z-tetraeno ic acid (5-HETE), a major early 5-lipoxygenase metabolic product. Exogenously added 5-HETE stimulated lung cancer cell growth in vitro. Inhibition of 5-lipoxygenase metabolism by selective antagonists resulted in significant growth reduction for a number of lung cancer cell lines. Primary clinical specimens and lung cancer cell lines express the message for the 5-lipoxygenase enzymes responsible for the generation of active metabolites. In vivo evaluation demonstrated that interruption of 5-lipoxygenase signaling resulted in enhanced levels of programmed cell death. These findings demonstrate that 5-lipoxygenase activation is involved with growth factor-mediated growth stimulation for lung cancer cell lines. Pharmacological intervention with lipoxygenase inhibitors may be an important new clinical strategy to regulate growth factor-dependent stages of lung carcinogenesis.

5-Lipoxygenase-Activating Proteins↗
PubMed1992

The in vitro dissociation kinetics of (R,R)-[125I]4IQNB is reflected in the in vivo washout of the radioligand from rat brain.

We have determined the kinetics of dissociation of (R)-3-Quinuclidinyl (R)-4-[125I]Iodobenzilate ((R,R)-[125I]4IQNB) from muscarinic acetylcholine receptor preparations from the cortex, hippocampus, caudate/putamen, thalamus, pons and colliculate bodies. The dissociation curves are well described by a biexponential function and are consistent with subtype selectivity favoring slow dissociation from the M1, M3, and M4 receptors with a 20-fold faster dissociation rate for the M2 receptor. Following intravenous injection, (R,R)-[125I]4IQNB binds to receptor in the rat brain in concentrations which reflect the receptor concentration present in a structure. We determined the extent of radioligand present at two times, 2 and 24 hrs, as an indication of the relative proportions of m-AChR which exhibits rapid vs. slow dissociation of (R,R)-[125I]4IQNB. A good correlation between in vitro and in vivo results suggests that the relative populations of receptor subtypes can be imaged using in vivo pharmacokinetics of (R,R)-[125I]4IQNB.

Animals↗
PubMed1988

Metabolism of murine and human embryos: search for a growth indicator in vitro culture medium.

Ham's F-10 medium was analyzed biochemically before and after growth of murine and human embryos. Ham's F-10 medium (280 mosm/kg, pH 7.4) alone, by means of reverse-phase high-performance liquid chromatography, demonstrated one major hydrophilic peak, which eluted at 4 to 8 minutes in a 10% to 48% acetonitrile gradient. This peak showed a single peptide of 50 kilodaltons in one-dimensional polyacrylamide gel electrophoresis and size exclusion high-performance liquid chromatography. After the growth of two-cell murine embryos to eight-cell embryos or blastocysts, the major hydrophilic peak was greatly reduced or absent in the culture medium, and in turn a major hydrophobic peak appeared that eluted at 29 minutes. The major hydrophobic peak could not be focused in one-dimensional polyacrylamide gel electrophoresis, but a high content of polar and nonpolar amino acids was revealed in N-terminal sequencing and mass spectrometric analysis. This shift in the peaks was not detected when embryos were cultured in the presence of 0.02% sodium azide. In vitro culture of human zygotes from the pronuclear stage to two to eight cells caused a similar disappearance of the major hydrophilic peak concomitant with the appearance of one to three major hydrophobic peaks in the culture medium. We conclude that the change in profile of culture medium from hydrophilic to hydrophobic peaks on high-performance liquid chromatography is indicative of the metabolic pattern of murine and human embryos. These data also indicate that murine and human embryos do not secrete any major peptide during their development in vitro.

Animals↗
PubMed1988

Bombesin: a potent mitogen for small cell lung cancer.

While advances in the diagnosis and staging of SCLC have been made over the past decade, overall therapeutic results remain essentially unchanged. However, during this time period there have been major advances in understanding the biology of this tumor cell type. The recognition of considerable heterogeneity among SCLC cells may be of prognostic importance, while the demonstration of specific growth factors, including bombesin, for this tumor type may open up new means for endocrine therapy of lung carcinoma in vivo. Over the next 5-10 yr, studies of clinical trials using specific antibodies or analogs of bombesin-like growth factors in patients with SCLC will define more clearly the role of BLI and GRP in patients with this disease.

Animals↗
PubMed1986

Factors influencing murine embryo bioassay: effects of proteins, aging of medium, and surgical glove coatings.

The 2-cell murine embryo bioassay as quality control for human in vitro fertilization (IVF) was used to evaluate the effects of protein supplements, medium aging, and surgical glove coatings. Ham's F-10 medium (GIBCO, Grand Island, NY) without protein supplementation supported growth of the 2-cell embryos to blastocysts. Addition of bovine serum albumin (BSA), fetal cord serum (FCS), or maternal serum (MS) did not enhance or reduce the blastulation rates (medium alone, 89.4%; BSA, 86.4%; FCS, 90%; MS, 74.7%). Unsupplemented Ham's F-10 medium was found to contain three major peaks of approximately 50,000 daltons and several minor peaks, analyzed on high-performance liquid chromatography (HPLC) and sodium sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), suggesting the presence of protein(s) in the medium itself. The storing of medium up to 425 days at 4 degrees C affected neither the HPLC profile nor its ability to support embryo growth (blastulation rates: fresh, 84%; stored 150 to 425 days, 77.7%). The coating of surgical gloves affected embryo growth. Both talc-coated (TC) and "talc-free," starch-coated (SC) surgical gloves were found to be progressively embryotoxic when they touched the medium for increasing lengths of time, compared with uncoated latex (UL) gloves and untouched control medium. Quality control of medium preparation and handling in murine embryo bioassay is reemphasized, with requirements for protein supplementation, use of fresh medium, and possible contamination with even talc-free, SC surgical gloves reevaluated.

Animals↗
PubMed1984

An atypical endocrine tumor of the lung responsive to radiation therapy and 5-fluorouracil-streptozotocin.

A case is reported of a patient who presented with a peripheral left upper-lobe lung mass, a thyroid nodule, and multiple enlarged cervical and supraclavicular lymph nodes. Fine-needle aspiration cytology of the lung lesion, the thyroid nodule, and several of the lymph nodes was interpreted as small cell cancer of the lung (SCCL). The patient was treated with Cytoxan (cyclophosphamide), Adriamycin (doxorubicin), and vincristine (CAV), alternating with VP-16 + cisplatin. When progressive disease was documented after three cycles of chemotherapy, an involved cervical lymph node was biopsied. By light microscopy (LM) the tumor appeared to be a poorly differentiated adenocarcinoma, but by transmission electron microscopy (TEM) it was found to have both neuroendocrine and glandular features. Biochemical analysis of the biopsy specimen revealed immunoreactive bombesin, and on immunoperoxidase staining many tumor cells contained neuron-specific enolase. The tumor was therefore classified as an atypical endocrine tumor of the lung (AETL), a recently described morphologic variant for which no therapy has yet been established. The patient was treated with radiation therapy (RT) followed by chemotherapy including 5-fluorouracil (5-FU) (500 mg/m2 IV, d 1-5) and streptozotocin (STZ) (500 mg/m2 IV, d 1-5) every 5-6 weeks, with objective evidence of tumor regression following each modality. This report illustrates the importance of ultrastructural study in the characterization of lung cancer, and indicates the need for the further evaluation of RT and 5FU + STZ in the treatment of neuroendocrine tumors of the lung.

Adenocarcinoma↗
PubMed1979

Uses of fluorescent cholinergic analogues to study binding sites for cholinergic ligands in Torpedo californica acetylcholine receptor.

A series of synthetic 1,n-bis(3-aminopyridinio)-alkane fluorescent probes have been used to determine the ligand binding properties of the acetylcholine receptor purified from Torpedo californica electroplax. At equilibrium, the probes bound to a single class of sites. The binding affinity of the fluorescent decamethonium analogues increased progressively as the number of methylene groups (n) increased from 4 to 12 and decreased in the range of 16--18 such groups. The receptor bound 1,12-bis(3-aminopyridinio)dodecane and 1,14-bis(3-aminopyridinio)tetradecane with the highest affinity while related monofunctional probes such as 1-(3-amino-pyridinio)propane were bound with a substantially lower affinity. The data indicate that the receptor interacts strongly with both ends of a bifunctional probe such as 1,14-bis(3-aminopyridinio)tetradecane. Also, competition between bifunctional fluorescent probe binding and the binding of conventional cholinergic ligands, was investigated and led to the conclusion that the probes, which are antagonists, form ternary complexes in the presence of acetylcholine.

Acetylcholine↗
PubMed1978

Interaction of bombesin and litorin with specific membrane receptors on pancreatic acinar cells.

We have prepared (125)I-labeled [Tyr(4)]bombesin and have examined the kinetics, stoichiometry, and chemical specificity with which the labeled peptide binds to dispersed acini from guinea pig pancreas. Binding of (125)I-labeled [Tyr(4)]-bombesin was saturable, temperature-dependent, and reversible and reflected interaction of the labeled peptide with a single class of binding sites on the plasma membrane of pancreatic acinar cells. Each acinar cell possessed approximately 5000 binding sites, and binding of the tracer to these sites could be inhibited by [Tyr(4)]bombesin [concentration for half-maximal effect (Kd), 2 nM], bombesin (Kd, 4 nM), or litorin (Kd, 40 nM) but not by eledoisin, physalemin, somatostatin, carbachol, atropine, secretin, vasocative intestinal peptide, neurotensin, or bovine pancreatic polypeptide. At high concentrations (>0.1 muM), cholecystokinin and caerulein each caused a small (15-20%) reduction in binding of lableled [Tyr(4)]bombesin. With bombesin, litorin, and [Tyr(4)]bombesin, there was a close correlation between the relative potency for inhibition of binding of labeled [Tyr(4)]bombesin and that for stimulation of amylase secretion. For a given peptide, however, a 10-fold higher concentration was required for half-maximal inhibition of binding than for half-maximal stimulation of amylase secretion, calcium outflux, or cyclic GMP accumulation. These results indicate that dispersed acini from guinea pig pancreas possess a single class of receptors that interact with [Tyr(4)]bombesin, bombesin, and litorin and that occupation of 25% of these receptors will cause a maximal biological response.

Amylases↗