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Biomedical subjects

D B Goodman

Publications and source records attributed to D B Goodman.

At least 55 records · Page 3Linked to original sources
PubMed1987

Histochemical and elemental localization of calcium in the granular cell subapical granules of the amphibian urinary bladder epithelium.

The ultrahistochemical analysis of apical granules in the epithelial cells, i.e., granular cells, of the amphibian urinary bladder using the N,N-naphthaloylhydroxylamine procedure identified the presence of calcium in these structures. Subsequent analytical microscopy employing fresh-frozen ultrathin cryosections for X-ray microanalysis of the granules further confirmed the above histochemical findings. In addition to calcium, elemental analysis indicated the presence of magnesium, phosphorus, sulfur, silicon, potassium, and chlorine either within or in close proximity to the granules. The possibility that these granules function as subcellular compartments for the uptake and storage of calcium ions, in a way similar to mitochondria, and thus function in intracellular calcium homeostasis, is discussed. Additionally, a role for this cation in the secretion of granular glycoproteins, i.e., stimulus-secretion coupling, is hypothesized.

Animals↗
PubMed1987

Hyperbaric hyperoxia reversibly inhibits erythrocyte phospholipid fatty acid turnover.

The present study is one component of a comprehensive investigation of oxygen tolerance of tissues and organs in normal human subjects. The focus of this study was the acylation of membrane phospholipid in situ by erythrocytes. Activation of exogenous [9,10-3H]oleic acid to acyl thioester and transesterification of the acyl thioester into phospholipid by intact human erythrocytes incubated in vitro decreased 30% after exposure of 10 human subjects to hyperbaric hyperoxia (100% O2, 3 ATA, 3.5 h). Partial recovery of activity could be detected when additional cells were obtained from these subjects and assayed in vitro 24 h after cessation of exposure. No significant change in membrane phospholipid fatty acid composition was detected under these conditions. The reduced glutathione content of intact erythrocytes increased by 15% after hyperbaric hyperoxia and remained elevated 24 h after exposure. In isolated membranes prepared from the same cells activation of [9,10-3H]oleic acid to acyl thioester and its transesterification into phospholipid did not change after hyperoxia. Since the ability of intact cells to replace oxidized fatty acids in membrane phospholipids via deacylation and reacylation in situ may be necessary for the maintenance of membrane integrity during exposure to oxidative stress, the decrease in [9,10-3H]oleic acid incorporation by human erythrocytes detected in vitro after hyperbaric hyperoxia in vivo may reflect an early event in the pathogenesis of oxygen-induced cellular injury and may be a useful index for assessment of the tolerance of tissues to hyperoxia.

Adult↗
PubMed1987

Electron microscopic cytochemical localization of Ca-ATPase in toad urinary bladder.

The calcium-regulating enzyme calcium adenosine triphosphatase (Ca-ATPase) was localized in the epithelium of amphibian urinary bladder by the one-step electron microscopic cytochemical procedure. The enzyme was identified along the basolateral border of the epithelial cells that comprise the bladder mucosa. The electron-dense precipitate indicating Ca-ATPase activity was seen in association with the outer leaflet of the basolateral plasmalemmae. Intracellularly, Ca-ATPase activity was seen in association with the mitochondrial matrix of the mitochondria-rich cells. Ca-ATPase was not seen along the apical microvillated border. Enzyme activity was also not seen after incubation in substrate-free media, calcium-free media, or incubation in the presence of vanadate. However, Ca-ATPase activity was evident when the calcium in the standard reaction medium was deleted in favor of magnesium. Addition of antidiuretic hormone (ADH; vasopressin) increased both the basolateral Ca-ATPase reaction and the mitochondrial reaction. Such data appear to indicate further that changes in cytosolic calcium ion concentration take place during the response of amphibian urinary bladder to the polypeptide hormone vasopressin.

Animals↗
PubMed1987

Electron microscopic cytochemical localization of adenylate cyclase in amphibian urinary bladder epithelium: effects of antidiuretic hormone.

A cytochemical technique for electron microscopic localization of adenylate cyclase was used to identify this enzyme in quiescent and hormone-stimulated toad urinary bladder epithelium. In the absence of vasopressin (antidiuretic hormone), adenylate cyclase was detected along the outer surface of the basolateral plasma membranes of granular cells, mitochondria-rich cells, and basal cells, the major cell types comprising the hormone-sensitive urinary epithelium. In the presence of antidiuretic hormone, the basolateral precipitates were markedly increased. The latter was true for both tissues incubated in the presence of an osmotic gradient and those stimulated in the absence of such a gradient. A significant mucosal reaction was never seen. Such data indicate that the hormone receptors for vasopressin are located along the basolateral membranes of all epithelial cells comprising the mucosal hormone-sensitive epithelium. All cells of the epithelium also demonstrate a vasopressin-sensitive adenylate cyclase. We discuss possible mechanisms that attempt to integrate the cytochemical data into an overall scheme for the physiological action of this hormone on amphibian urinary bladder.

Adenylyl Cyclases↗
PubMed1986

t-Butyl hydroperoxide alters fatty acid incorporation into erythrocyte membrane phospholipid.

Because the ability of cells to replace oxidized fatty acids in membrane phospholipids via deacylation and reacylation in situ may be an important determinant of the ability of cells to tolerate oxidative stress, incorporation of exogenous fatty acid into phospholipid by human erythrocytes has been examined following exposure of the cells to t-butyl hydroperoxide. Exposure of human erythrocytes to t-butyl hydroperoxide (0.5-1.0 mM) results in oxidation of glutathione, formation of malonyldialdehyde, and oxidation of hemoglobin to methemoglobin. Under these conditions, incorporation of exogenous [9,10-3H]oleic acid into phosphatidylethanolamine is enhanced while incorporation of [9,10-3H]oleic acid into phosphatidylcholine is decreased. These effects of t-butyl hydroperoxide on [9,10-3H]oleic acid incorporation are not affected by dissipating transmembrane gradients for calcium and potassium. When malonyldialdehyde production is inhibited by addition of ascorbic acid, t-butyl hydroperoxide still decreases [9,10-3H]oleic acid incorporation into phosphatidylcholine but no stimulation of [9,10-3H]oleic acid incorporation into phosphatidylethanolamine occurs. In cells pre-treated with NaNO2 to convert hemoglobin to methemoglobin, t-butyl hydroperoxide reduces [9,10-3H]oleic acid incorporation into phosphatidylcholine by erythrocytes but does not stimulate [9,10-3H]oleic acid incorporation into phosphatidylethanolamine. Under these conditions oxidation of erythrocyte glutathione and formation of malonyldialdehyde still occur. These results indicate that membrane phospholipid fatty acid turnover is altered under conditions where peroxidation of membrane phospholipid fatty acids occurs and suggest that the oxidation state of hemoglobin influences this response.

Calcium↗
PubMed1986

Phenytoin hypersensitivity: a case of severe acute rhabdomyolysis.

A 22-year-old black man was hospitalized with fever, rash, myalgias, and marked periorbital and facial edema three months after beginning phenytoin therapy. His hospital course was marked by an initial serum creatine phosphokinase level of 85,000 IU/liter, which rose to a peak value of 242,000 IU/liter on the third hospital day and a striking eosinophilia (8,400/microliter). Muscle biopsy revealed only early fiber necrosis with partial dissolution of the sarcoplasm without evidence of inflammation, vasculitis, regeneration, or parasitic infection. When therapy with phenobarbital, a structural congener of phenytoin, was begun, the patient had an exacerbation of his rash and became febrile again.

Acute Disease↗
PubMed1986

Antidiuretic hormone response in the amphibian urinary bladder: time course of cytochalasin-induced vacuole formation, an ultrastructural study employing ruthenium red.

Cytochalasin is known to inhibit the antidiuretic hormone-induced hydro-osmotic response (bulk water flow) in the amphibian urinary bladder without altering hormone-stimulated diffusional water permeability or short-circuit current. In addition, histological studies have shown that the mold metabolite induces the formation of large intracellular vacuoles or lakes in the epithelial cells. We report here a transmission electron microscopic time-course study which indicates that during the early phases of the ADH response cytochalasin causes the formation of numerous multivesicular bodies or aggregates derived from individual basolateral pinocytotic vesicles. Because of their apparent hypertonic nature, the vesicles, as well as the vesicular aggregates, accumulate water during hormone-stimulated hydro-osmotic flow. As a result, the multivesicular bodies dilate and fuse to form the large intracellular lakes characteristic of cytochalasin treatment in the presence of both an applied osmotic gradient and vasopressin. In the presence of mucosal ruthenium red, the luminal glycocalyx was heavily stained with this tracer. At no time, however, even in the presence of hormone, was there any evidence for the uptake of this dye at the apical epithelial border. In the presence of serosal ruthenium red, the lateral intercellular spaces, basolateral pinocytotic vesicles, basal lamina, and collagen, as well as other subepithelial structures, were ruthenium positive. With cytochalasin D, vasopressin, and serosal ruthenium red, both the pinocytotic vesicles and the multivesicular bodies demonstrated an apparent membrane associated ruthenium positive coat. The tracer data indicates that the basolateral pinocytotic vesicles, increased by the presence of hormone, are indeed endocytotic in nature. The mucopolysaccharide coat associated with these structures may be involved in ionic and/or fluid transport.

Animals↗
PubMed1986

Cell surface antigen identification by a modified fluorescein immunosphere method.

Fluorescein immunospheres may be used in an indirect technic to label lymphocyte cell surface antigens. Wright's counter-staining allows simultaneous identification of fine morphology and surface antigen properties. Studies designed to determine methods for separating cells with bound immunospheres from free immunospheres revealed that removal of unbound immunospheres by flotation over cold protein solution creates excessive numbers of false negatives. Glutaraldehyde cross-linking of the primary and secondary antibodies linking immunospheres to the lymphocyte stabilizes the complex. This modification of the fluorescein immunosphere method compares favorably with flow cytometry.

Adult↗
PubMed1986

Cytochemical localization of malate synthase in amphibian fat body adipocytes: possible glyoxylate cycle in a vertebrate.

The adipocytes of amphibian abdominal fat bodies contain typical microperoxisomes, as indicated by their fine structure. Electron microscopic cytochemistry showed that these organelles contain the enzymes catalase, typical for peroxisomes, and malate synthase. The latter is an enzymatic component characteristic of the glyoxylate cycle, a biochemical pathway known to exist in plant glyoxysomes (peroxisomes). This metabolic pathway makes possible the net conversion of lipid to carbohydrate. Toad adipocytes may represent yet another example of vertebrate peroxisomes which contain one of the marker enzymes (malate synthase) characteristic of the glyoxylate shunt.

Adipose Tissue↗
PubMed1986

Aminoglycoside toxicity: pH dependent inhibition of ADH response.

The effect of aminoglycoside antibiotics on the response of the isolated toad urinary bladder to antidiuretic hormone (ADH) was investigated. Gentamicin and neomycin both acidify the serosal bathing solution and cause a dose-dependent inhibition of the hydroosmotic response to ADH, while streptomycin has minimal effect on media pH and causes no inhibition of the response to ADH. Detailed studies employing gentamicin indicate that acidification stimulates production of PGE2, a known inhibitor of the hydroosmotic response of the toad bladder to ADH. When media pH is rigidly controlled or PGE2 production is inhibited by indomethacin, the inhibitory effect of gentamicin on the response to ADH is ameliorated. These studies suggest that the defect in renal concentrating ability seen as part of aminoglycoside nephrotoxicity could be due, in part, to an acidification-induced, prostaglandin-mediated resistance to the action of ADH.

Aminoglycosides↗
PubMed1985

Preparation of inside-out vesicles from erythrocyte membranes inactivates the pathway for oleic acid incorporation into phospholipid.

The pathway for membrane phospholipid fatty acid turnover in situ may be important in the regulation of the composition and turnover of the lipid microenvironment of membrane proteins. This pathway has been characterized further by studying the activation and incorporation of [9,10(n)-3H]oleic acid and transesterification of [1-14C]oleoyl-CoA into membrane phospholipids by isolated erythrocyte membrane ghosts and inside-out vesicles derived from these ghosts. Erythrocyte ghosts and sealed vesicles of defined orientation prepared from them have been widely employed in studies of the function of membrane proteins, particularly those which mediate the transport of ions and sugars. Preparation of inside-out vesicles from ghosts by exposure to alkaline hypotonic conditions results in elution of some membrane proteins but no loss of membrane phospholipid. Compared to ghosts, the ability of inside-out vesicles to activate and incorporate [9,10(n)-3H]oleic acid into phospholipid is diminished by over 90% and the ability of inside-out vesicles to transesterify [1-14C]oleoyl-CoA to phospholipid is diminished by over 50%. These findings indicate that exposure of erythrocyte membranes to the alkaline hypotonic conditions required for inside-out vesicle preparation results in loss or inactivation of both acyl-CoA ligase and acyl-CoA-lysophospholipid acyltransferase activities. This lability of the enzymes for in situ phospholipid fatty acid turnover should be considered in the design and interpretation of studies concerned with elucidation of the relationship between phospholipid fatty acid turnover and the regulation of membrane protein function in this membrane preparation.

1-Acylglycerophosphocholine O-Acyltransferase↗
PubMed1985

The relationship between valinomycin-induced alterations in membrane phospholipid fatty acid turnover, membrane potential, and cell volume in the human erythrocyte.

The relationship between alterations in transmembrane potential, cell volume, and phospholipid fatty acid turnover has been examined in human erythrocytes by treating the cells with the monovalent cation ionophore valinomycin. Valinomycin increases the cellular uptake of tetra[3H]phenylphosphonium ion by erythrocytes, indicating membrane hyperpolarization, and causes net loss of potassium chloride and water from the cells leading to a decrease in cell volume. Treatment of erythrocytes with valinomycin also enhances incorporation of [9, 10-(3)H]oleic acid into phospholipids, primarily diacylphosphatidylethanolamine. After replacing intracellular chloride with sulfate and treating cells with the anion transport inhibitor 4,4'-diisothiocyanostilbene-2,2'-disulfonate, exposure to valinomycin results in uptake of tetra[3H]phenylphosphonium ion and stimulation of [9, 10-(3)H]oleic acid incorporation, but, because anion efflux is prevented, no decrease in cell volume occurs. When tetra[3H]phenylphosphonium ion uptake is also prevented by suspending these cells in 125 mM KCl to dissipate the transmembrane potassium gradient, valinomycin still enhances [9, 10-(3)H] oleic acid incorporation into phospholipid. These results suggest that the presence of valinomycin in the membrane directly alters phospholipid fatty acid turnover and that some of the effects of this ionophore on cellular function previously attributed to alterations in transmembrane potential or cellular potassium content may instead be due to altered phospholipid turnover. Since it is possible that valinomycin may directly perturb phospholipid fatty acid turnover in other cells, the possibility that valinomycin-induced alterations in cellular function are due to altered phospholipid turnover rather than membrane hyperpolarization or altered potassium content should be considered in the interpretation of studies employing this ionophore.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed1985

Activation of actin-containing microfilaments by vasopressin in the amphibian urinary bladder epithelium: a fluorescent study using NBD-phallacidin.

The effect of an antidiuretic hormone (ADH, vasopressin) on the microfilament system of the toad urinary bladder lumenal epithelium was investigated using NBD-phallacidin (NBD-ph). The latter material is a specific fluorescent label for F actin. In the presence of an osmotic gradient, both ADH and cyclic adenosine monophosphate (cAMP) appear to induce the polymerization of monomeric actin into F actin-containing microfilaments. The latter may then be involved in the morphological changes, including the formation of lateral intercellular lakes, associated with the typical hydroosmotic response.

Actins↗
PubMed1985

Detection of the ovulatory luteinizing hormone (LH) surge with a semiquantitative urinary LH assay.

We examined blood concentrations of ovarian steroid hormones (E2, P) and serum LH concentrations to establish that the Ovu-STICK assay reliably reflects endocrine events in the periovulatory period. In all 16 cycles studied, which included 2 cycles in which the women received CC, the ovulatory surge of LH was detected with the use of the Ovu-STICK assay. In contrast, BBT monitoring correctly predicted the ovulatory event in only half the cycles.

Clomiphene↗
PubMed1985

Normobaric hyperoxia in vivo inhibits fatty acid incorporation into sheep erythrocyte phospholipid in vitro.

Oxygen toxicity is a major complication of normobaric hyperoxia in therapeutic settings. Because alterations in membrane function occurring as a consequence of peroxidation of membrane phospholipid fatty acids may be an early event in the pathogenesis of oxygen-induced injury, we studied the effects of hyperoxia on the ability of the membrane to repair itself by incorporating fatty acid via the pathway for deacylation and reacylation in situ. Although the lung is the major site of clinically significant injury, the erythrocyte is also directly exposed to elevated PO2 in vivo. In this study, incorporation of [9,10(-3)H]-oleic acid into phospholipid has been measured in sheep erythrocytes in vitro after exposure of four animals to normobaric hyperoxia in vivo. [9,10(-3)H]-Oleic acid incorporation into erythrocyte phospholipid decreased within 24 hours and reached 50% of pre-exposure levels after 70 hours of exposure to 100% O2. No significant change in the fatty acid composition of membrane phospholipid was detected under these conditions. In contrast to the results with intact cells, incorporation of [9,10(-3)H]-oleic acid into phospholipid by isolated erythrocyte membranes prepared from the cells of two animals increased after 70 hours of exposure to 100% O2, indicating that the inhibition of fatty acid incorporation in intact erythrocytes does not result from irreversible inactivation of the enzymes involved in acylation of endogenous lysophospholipid. Because the ability of cells to replace membrane phospholipid fatty acids via deacylation and reacylation in situ could be important in the maintenance of membrane integrity during oxidative stress, the decrease in fatty acid incorporation by erythrocytes in vitro may reflect an early event in the pathogenesis of oxygen-induced cellular injury.

Animals↗
PubMed1985

Identification of hyperthyroid patients by means of a sensitive assay for thyrotropin.

We evaluated a new assay (TSH3 MAIAclone) for thyrotropin (TSH) with improved sensitivity, testing a series of hospital inpatients with increased free thyroxin indices (thyroxin concentration X triiodothyronine uptake on resin). This assay involves use of three monoclonal antibodies and an antibody-magnetic particle conjugate that rapidly and completely separates bound and free tracer in a magnetic field. The assay turnaround time is 3 h. By the TSH3-MAIAclone assay, 65% of these patients with an increased free thyroxin index were identified on the basis of a TSH value less than or equal to 0.50 milli-int. unit/L. In contrast, another commercially available assay for TSH detected suppressed TSH concentrations in less than 5% of these patients. We conclude that the TSH3 MAIAclone assay markedly improves our ability to discriminate hyperthyroidism from euthyroidism.

Antibodies, Monoclonal↗
PubMed1982

Studies of the Ca2+ transport mechanism of human erythrocyte inside-out membrane vesicles. Evidence for the development of a positive interior membrane potential.

Previous observations on the effects of permeant anions on ATP-dependent calcium transport in inside-out vesicles prepared from human erythrocytes suggested that the calcium pump is electrogenic, generating a positive interior membrane potential. The present work demonstrates the development of a positive interior membrane potential across inside-out vesicle membranes during calcium transport in the absence of permeant anions. Several membrane potential probes, 1-anilino-8-naphthalenesulfonate, 3,3'-dipropylthiodicarbocyanine iodide, and an electron paramagnetic resonant triphenylphosphonium derivative, provide qualitative evidence for the development of a membrane potential. Moreover, a number of parallels are observed between the changes in the membrane potential measured by the probes and calcium transport. These include enhancement by calmodulin, time course of change, similar kinetic properties, and the requirement for intact vesicle membranes. Quantitative measurements of the membrane potential shows a positive interior membrane potential of 26-37 mV using radiolabeled permeant anion distribution and 38-57 mV using 3,3'-dipropylthiodicarbocyanine iodide fluorescence changes. These membrane potentials are of a similar magnitude to those reported for the sarcoplasmic reticulum calcium pump (Zimniak, P., and Racker, E. (1978). J. Biol. Chem. 253, 4631-4637).

Anilino Naphthalenesulfonates↗