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1.
Invest New Drugs ; 33(2): 389-96, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25523151

ABSTRACT

PURPOSE: Inhibiting survivin and Cdc2 (CDK1) has preclinical anti-leukemic activity. Terameprocol is a small molecule survivin and Cdc2/CDK1 inhibitor that was studied in a Phase I dose-escalation trial. PATIENTS AND METHODS: Sixteen patients with advanced acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS) were enrolled and 15 treated with Terameprocol in three dose cohorts intravenously three times per week for 2 weeks every 21 days. RESULTS: Patients had AML (n = 11), chronic myelogeneous leukemia in blast phase (CML-BP, n = 2) and one each T-cell acute lymphoblastic leukemia (T-ALL) and MDS. Four, five and six patients were treated at the 1000, 1500 and 2200 mg Terameprocol dose cohorts respectively. Common related treatment emergent adverse events (TEAE) were grade 1 or 2 headache, transaminitis and pruritus, with one grade 4 serious AE (SAE) of pneumonia. No dose limiting toxicity (DLT) was observed, however, due to other observed grade 3 TEAE the recommended phase 2 dose (RP2D) was determined at 1500 mg 3×/week for 2 weeks of a 21-day cycle. Partial remission and transfusion independence in a CML-BP patient (1500 mg cohort) and hematological improvement in erythroid (HI-E) and platelet lineage (HI-P) in an AML patient were observed. Five AML patients had stable disease greater/equal to 2 months. Pharmacodynamic studies showed a reduction of CDK1 and phospho-AKT protein expression. CONCLUSION: Terameprocol can be safely administered to advanced leukemia patients, sufficient drug exposure was obtained and clinical activity and biomarker modulation were observed.


Subject(s)
Antineoplastic Agents/pharmacokinetics , CDC2 Protein Kinase/antagonists & inhibitors , Leukemia/drug therapy , Masoprocol/analogs & derivatives , Adult , Aged , Antineoplastic Agents/administration & dosage , Antineoplastic Agents/adverse effects , Chemistry, Pharmaceutical , Dose-Response Relationship, Drug , Drug Administration Schedule , Female , Humans , Liver Function Tests , Male , Masoprocol/administration & dosage , Masoprocol/adverse effects , Masoprocol/pharmacokinetics , Maximum Tolerated Dose , Middle Aged , Polyethylene Glycols/chemistry , Remission Induction
2.
Ann Occup Hyg ; 51(2): 161-72, 2007 Mar.
Article in English | MEDLINE | ID: mdl-17046960

ABSTRACT

OBJECTIVES: This study presents a procedure allowing the numerical synthesis of exposure data reported in different ways in the literature, including summary parameters and single measurements. The procedure was applied to literature regarding formaldehyde exposure in the reconstituted wood panels industry, including oriented-strand board (OSB), medium density fibre board (MDF) and particle board (PB). METHODS: For each publication providing summary parameters we estimated geometric means (GM) and geometric standard deviations (GSD) by assuming lognormality of exposure levels. Monte Carlo simulation was performed to re-create datasets from the sample sizes and estimated GMs and GSDs, allowing their subsequent formatting together with the single measurements. The precision and bias of the methods used to estimate GMs and GSDs were evaluated. RESULTS: Altogether, the 13 articles included in our study yielded a final database of 874 data, of which 732 were simulated. For both area and personal data, exposures corresponding to MDF and PB were similar while OSB levels were lower. The most recent available personal levels (1985-1994) were highest in PB for jobs performed in the vicinity of the press (GM=0.63 mg m-3). Corresponding area levels were highest for PB in the main production zone (GM=0.43 mg m-3). Mixed-effects models fitted to area PB data explained 38% of the total variability. A 6-fold decrease in exposures from 1965 to 1995 was estimated. Replication of the simulation process yielded relative standard deviations of the calculated GMs and GSDs between 10 and 20%. The relative biases of the methods used to estimate GMs and GSDs varied across methods and decreased with higher sample sizes (from approximately 15% for n=5 to less than 5% for n=30, in absolute value). The precision also varied across methods and improved with higher sample sizes (from approximately 30% for n=5 to approximately 10% for n=30). DISCUSSION: This methodology constitutes a new meta-analysis tool that should improve the interpretation of industrial hygiene literature data, but needs to be further validated.


Subject(s)
Environmental Pollutants/analysis , Formaldehyde/analysis , Manufactured Materials/analysis , Occupational Exposure/analysis , Air Pollutants, Occupational , Databases, Factual , Hazardous Substances/analysis , Humans , Industry , Monte Carlo Method , Publications , Risk Assessment/methods , Wood , Workplace
3.
Anal Bioanal Chem ; 381(8): 1540-5, 2005 Apr.
Article in English | MEDLINE | ID: mdl-15770470

ABSTRACT

Domoic acid (DA) is a naturally-occurring amino acid that causes a form of human intoxication called amnesic shellfish poisoning (ASP) following the consumption of shellfish. A rapid and sensitive HPLC-UV method has been developed for analysis of DA and analogues in shellfish without the need for SPE clean-up. Isocratic chromatographic separation of DA and its isomers from shellfish matrix interferences and from the prevalent amino acid, tryptophan, was achieved by careful control of the mobile phase pH. The optimised pH was found to be 2.5 when using a Luna(2) C18 column. Sample extraction was verified with control extracts from shellfish spiked at 5.0 and 10.0 microg/g of DA and with certified reference material. The average extraction efficiency was 98.5%. The calibration, based on mussel tissue spiked with DA standard, was linear in the range 0.05-5.0 microg/ml (r = 0.9999) and the detection limit (signal:noise 3:1) was better than 25 ng/ml. The DA assay achieved good precision; %RSD = 1.63 (intra-day, n = 6) and %RSD = 3.7 (inter-day, n = 8). This method was successfully applied to a variety of shellfish species, allowing the rapid screening of a large number of samples per day (20-30), without the need for SPE clean-up. Quantitative data were obtained for shellfish samples containing domoic acid in the concentration range 0.25-330 microg/g. Using the same chromatographic conditions, LC-MS3 was used to determine DA and its isomers, isodomoic acid D and epi-domoic acid, in scallop tissues.


Subject(s)
Chromatography, High Pressure Liquid/methods , Kainic Acid/analogs & derivatives , Kainic Acid/analysis , Marine Toxins/analysis , Shellfish/analysis , Animals , Hydrogen-Ion Concentration , Molecular Structure , Shellfish Poisoning , Spectrometry, Mass, Electrospray Ionization/methods
4.
J Neurooncol ; 53(2): 161-76, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11716068

ABSTRACT

Microarray analysis of complementary DNA (cDNA) allows large-scale, comparative, gene expression profiling of two different cell populations. This approach has the potential for elucidating the primary transcription events and genetic cascades responsible for increased glioma cell motility in vitro and invasion in vivo. These genetic determinants could become therapeutic targets. We compared cDNA populations of a glioma cell line (G112) exposed or not to a motility-inducing substrate of cell-derived extracellular matrix (ECM) proteins using two sets of cDNA microarrays of 5,700 and 7,000 gene sequences. The data were analyzed considering the level and consistency of differential expression (outliers) and whether genes involved in pathways of motility, apoptosis, and proliferation were differentially expressed when the motility behavior was engaged. Validation of differential expression of selected genes was performed on additional cell lines and human glioblastoma tissue using quantitative RT-PCR. Some genes involved in cell motility, like tenascin C, neuropilin 2, GAP43, PARG1 (an inhibitor of Rho), PLCy, and CD44, were over expressed; other genes, like adducin 3y and integrins, were down regulated in migrating cells. Many key cell cycle components, like cyclin A and B, and proliferation markers, like PCNA, were strongly down regulated on ECM. Interestingly, genes involved in apoptotic cascades, like Bcl-2 and effector caspases, were differentially expressed, suggesting the global down regulation of proapoptotic components in cells exposed to cell-derived ECM. Overall, our findings indicate a reduced proliferative and apoptotic activity of migrating cells. cDNA microarray analysis has the potential for uncovering genes linking the phenotypic aspects of motility, proliferation, and apoptosis.


Subject(s)
Brain Neoplasms/pathology , Gene Expression Regulation, Neoplastic , Glioma/pathology , Neoplasm Invasiveness/genetics , Neoplasm Proteins/biosynthesis , Transcription, Genetic , Apoptosis/genetics , Brain Neoplasms/chemistry , Cell Cycle Proteins/biosynthesis , Cell Cycle Proteins/genetics , Cell Movement/drug effects , Cell Movement/genetics , Computer Systems , Culture Media/pharmacology , DNA, Complementary/genetics , Expressed Sequence Tags , Extracellular Matrix Proteins/pharmacology , Gene Expression Profiling , Gene Expression Regulation, Neoplastic/drug effects , Glioblastoma/chemistry , Glioblastoma/pathology , Growth Substances/biosynthesis , Growth Substances/genetics , Humans , Lasers , Neoplasm Proteins/genetics , Oligonucleotide Array Sequence Analysis , Phenotype , Polymerase Chain Reaction , Tenascin/biosynthesis , Tenascin/genetics , Transcription, Genetic/drug effects , Tumor Cells, Cultured/drug effects , Tumor Cells, Cultured/metabolism , Tumor Cells, Cultured/pathology
5.
Clin Cancer Res ; 7(8): 2480-9, 2001 Aug.
Article in English | MEDLINE | ID: mdl-11489830

ABSTRACT

PURPOSE: To discover the genetic determinants of glioma invasion in vivo, we compared the mRNA expression profiles of glioblastoma cells residing at the tumor core versus those at the invasive rim of a human tumor resection. EXPERIMENTAL DESIGN: From a single glioblastoma specimen, 20,000 individual cells from each region (core and invasive rim) were collected by laser capture microdissection and analyzed by mRNA differential display. Differential expression of gene candidates was confirmed by laser capture microdissection and quantitative reverse transcription-PCR in additional glioblastoma multiforme specimens, and the role in migration was further evaluated in glioma cell lines in vitro. RESULTS: Reproducible overexpression the death-associated Protein 3 (Dap-3) mRNA (NM 004632, GenBank; also reported as human ionizing resistance conferring protein mRNA, HSU18321, GenBank) by invasive cells was identified. Although the full-length Dap-3 protein has been described as proapoptotic, the NH(2)-terminal fragment can act in a dominant negative way resulting in protection from programmed cell death. In glioma cell lines T98G and G112 with an induced motility phenotype, Dap-3 was up-regulated at the mRNA and protein level as assessed by quantitative reverse transcription-PCR, cDNA microarray, and Western blot analysis. These cells showed an increased resistance to undergo camptothecin-induced apoptosis, which was overcome by effective Dap-3-antisense treatment. Antisense treatment also decreased the migration ability of T98G cells. CONCLUSIONS: Dap-3 is up-regulated in invasive glioblastoma multiforme cells in vivo and in glioma cells with an induced motility phenotype in vitro. When migration is activated, Dap-3 is up-regulated and cells become resistant to apoptosis. These findings suggest that Dap-3 confers apoptosis-resistance when migration behavior is engaged.


Subject(s)
Cell Movement , Glioblastoma/pathology , Proteins/genetics , Apoptosis/drug effects , Apoptosis Regulatory Proteins , Cell Movement/drug effects , Cell Movement/genetics , DNA, Antisense/pharmacology , Dose-Response Relationship, Drug , Extracellular Matrix/physiology , Gene Expression Regulation, Neoplastic/drug effects , Glioblastoma/genetics , Humans , Immunohistochemistry , Laminin/pharmacology , Neoplasm Invasiveness , Phenotype , Proteins/analysis , RNA, Messenger/drug effects , RNA, Messenger/genetics , RNA, Messenger/metabolism , RNA-Binding Proteins , Ribosomal Proteins , Tumor Cells, Cultured
6.
Cancer Res ; 61(10): 4190-6, 2001 May 15.
Article in English | MEDLINE | ID: mdl-11358844

ABSTRACT

The mRNA expression profiles from glioblastoma cells residing at the tumor core and invasive rim of a human tumor resection were compared. From a single tumor specimen, 20,000 single cells from each region were collected by laser capture microdissection. Differential expression of 50-60 cDNA bands was detected. One of the sequences overexpressed by the invasive cells showed 99% homology to the P311 gene, the protein product of which is reported to localize at focal adhesions. Relative overexpression of P311 by invading glioblastoma cells compared with tumor core was confirmed by quantitative reverse transcription-PCR of six glioblastoma specimens after laser capture microdissection collection of rim and core cells. In vitro studies using antisense oligodeoxynucleotides and integrin activation confirmed the role of P311 in supporting migration of malignant glioma cells. Immunochemistry studies confirmed the presence of the P311 protein in tumor cells, particularly at the invasive edge of human glioblastoma specimens.


Subject(s)
Glioblastoma/genetics , Nerve Tissue Proteins , Oncogene Proteins/genetics , Amino Acid Sequence , Cell Movement/physiology , Dissection , Gene Expression Profiling , Glioblastoma/pathology , Humans , Lasers , Molecular Sequence Data , Neoplasm Invasiveness , Oligonucleotides, Antisense/genetics , Oligonucleotides, Antisense/pharmacology , Oncogene Proteins/physiology , Oncogenes , Reproducibility of Results , Reverse Transcriptase Polymerase Chain Reaction , Tumor Cells, Cultured
7.
Nature ; 406(6795): 536-40, 2000 Aug 03.
Article in English | MEDLINE | ID: mdl-10952317

ABSTRACT

The most common human cancers are malignant neoplasms of the skin. Incidence of cutaneous melanoma is rising especially steeply, with minimal progress in non-surgical treatment of advanced disease. Despite significant effort to identify independent predictors of melanoma outcome, no accepted histopathological, molecular or immunohistochemical marker defines subsets of this neoplasm. Accordingly, though melanoma is thought to present with different 'taxonomic' forms, these are considered part of a continuous spectrum rather than discrete entities. Here we report the discovery of a subset of melanomas identified by mathematical analysis of gene expression in a series of samples. Remarkably, many genes underlying the classification of this subset are differentially regulated in invasive melanomas that form primitive tubular networks in vitro, a feature of some highly aggressive metastatic melanomas. Global transcript analysis can identify unrecognized subtypes of cutaneous melanoma and predict experimentally verifiable phenotypic characteristics that may be of importance to disease progression.


Subject(s)
Gene Expression Profiling , Melanoma/classification , Skin Neoplasms/classification , Adult , Cluster Analysis , Disease Progression , Female , Humans , Male , Melanoma/genetics , Middle Aged , Neoplasm Invasiveness , Prognosis , RNA, Messenger/metabolism , Skin Neoplasms/genetics , Tumor Cells, Cultured , Uveal Neoplasms/classification , Uveal Neoplasms/genetics
8.
Org Lett ; 1(11): 1827-9, 1999 Dec 02.
Article in English | MEDLINE | ID: mdl-10836042

ABSTRACT

[formula: see text] The 6,8-dioxabicyclo[3.2.1]octane skeleton is a common structural subunit in natural products. A conceptionally new strategy affording these structures is described for the syntheses of (+)-exo-brevicomin and rac-endo- and enantiomerically enriched (+)-endo-brevicomin, employing desymmetrization of trienes derived from diols with C2 and meso symmetry via ring-closing metathesis.


Subject(s)
Bridged Bicyclo Compounds, Heterocyclic/chemical synthesis , Heterocyclic Compounds, 2-Ring/chemical synthesis , Octanes/chemical synthesis , Sex Attractants/chemical synthesis , Animals , Catalysis , Coleoptera/chemistry , Stereoisomerism
9.
Endocrinology ; 137(6): 2558-64, 1996 Jun.
Article in English | MEDLINE | ID: mdl-8641209

ABSTRACT

We have described a thyroid hormone receptor in synaptosomes of the chick embryo brain. To understand how the hormones exert their actions at this level, we performed a series of studies to demonstrate that this receptor could be linked to G proteins. Guanosine 5'-[gamma-thio]triphosphate (GTP gamma S)(100 muM) lowered the binding capacity of the receptor high affinity site from 8.9 +/- 1.3 to 3.4 +/- 1.3 ng T3/mg protein, a finding consistent with the coupling of receptor to G proteins. Furthermore, ADP ribosylation with pertussis toxin showed that thyroid hormones induced a dose-dependent increase in the inactive alpha 0-subunit of the G0 protein. This effect was detected at 10 pM, with a maximal increase (mean +/- SEM, 50 +/- 3.6%) at 100 nM, and T4 was as effective as T3. Both hormones also decreased the intrinsic guanine triphosphatase activity of G proteins by lowering the binding of GTP to the alpha-subunit and their rate of hydrolysis. This inhibition was greater with T4 (25 +/- 5%) than with T3 (14 +/- 2%), suggesting that the former could be the more active hormone at the synaptosomal level. The effect on guanine triphosphatase activity confirms that the synaptosomal thyroid hormone receptor is coupled to a G(zero) protein. These results demonstrate that thyroid hormones increase or favor the ADP ribosylation of G alpha(zero) by pertussis toxin. Thus, they enhance the alpha(zero)-GDP form of the G(zero) protein, namely its inactive conformation. By decreasing the activity of this protein, these hormones may modulate the formation of second messengers in synaptosomes and intervene in the regulation of neuronal proliferation and differentiation induced by several factors. Therefore, thyroid hormones may exert their action on brain maturation at least in part by modulating G alpha(zero) through their synaptosomal receptor.


Subject(s)
Brain/embryology , GTP-Binding Proteins/metabolism , Receptors, Thyroid Hormone/metabolism , Synaptosomes/metabolism , Thyroxine/pharmacology , Triiodothyronine/pharmacology , Adenosine Diphosphate Ribose/metabolism , Animals , Brain/drug effects , Brain/metabolism , Chick Embryo , GTP Phosphohydrolases/metabolism , Guanosine 5'-O-(3-Thiotriphosphate)/pharmacology , Pertussis Toxin , Synaptosomes/drug effects , Thyroxine/metabolism , Triiodothyronine/metabolism , Virulence Factors, Bordetella/pharmacology
10.
Can J Physiol Pharmacol ; 73(12): 1784-94, 1995 Dec.
Article in English | MEDLINE | ID: mdl-8834493

ABSTRACT

The involvement of various phosphodiesterases (PDEs) in controlling the time-dependent mechanical properties of guinea pig trachealis smooth muscles was determined by using different classes of PDE inhibitors as pharmacological tools. These drugs produced low amplitude and long-lasting dose-dependent relaxations on the resting tone with the following EC50 values: rolipram, 3 nM; indolidan, 0.11 microM; and zaprinast, 0.5 nM and 1 microM. These PDE inhibitors were 50% less active than 1 microM norepinephrine. The effects of the drugs were also tested on carbachol-induced contractions and norepinephrine-evoked relaxations. Zaprinast, but not rolipram nor indolidan, decreased the rate of rise of contraction, thus prolonging the time to reach the plateau by 75% without modifying the magnitude of the responses. Zaprinast and rolipram significantly increased the total length of the norepinephrine effect by 25 and 35%, respectively. Similar results were obtained in a dose-dependent manner on isoproterenol-induced relaxations. In contrast, a higher concentration of indolidan was required to affect the amplitude, duration, and time to peak of isoproterenol- or norepinephrine-induced relaxations. These results indicate that PDE IV (rolipram sensitive) and PDE I, and less likely PDE V (both zaprinast sensitive), are involved in the control of guinea pig airway contractile kinetics, whereas PDE III (indolidan sensitive) is essentially involved in the modulation of the resting tone. Four cytosolic isozymes were identified in bovine airway smooth muscles (ASMs); PDE I (calmodulin-dependent PDE), PDE II (cGMP-stimulated PDE), PDE IV (cAMP-specific and rolipram-sensitive PDE), and PDE V (cGMP-specific and zaprinast-sensitive PDE). Characterization of PDE isoforms present in the microsomal fraction by HPLC showed the presence of PDE IV, PDE V, and to a lesser extent PDE III. However, PDE III was not detected in ASM cytosol. Using newly synthesized radioligands, binding studies confirmed the low level of expression of PDE III and the presence of PDE IV. We conclude that PDE I controls the rate of contraction, whereas PDE V and PDE IV prolong the time of relaxation induced by NE. PDE V would control the ASM responsiveness by regulating the intracellular cGMP concentration, which in turn would both activate PKG and stimulate PDE II (cGS-PDE). Since the various isozymes of PDE are differently involved in the kinetic control of the mechanical events in ASM, they represent physiologically relevant and important pharmacological targets.


Subject(s)
Muscle Contraction/drug effects , Muscle, Smooth/drug effects , Muscle, Smooth/enzymology , Phosphodiesterase Inhibitors/pharmacology , Trachea/drug effects , Animals , Carbachol/pharmacology , Cattle , Cyclic AMP/metabolism , Cyclic GMP/metabolism , Cytosol/enzymology , Dogs , Guinea Pigs , Isoenzymes/pharmacology , Kinetics , Membrane Proteins/chemistry , Muscle Relaxation/drug effects , Norepinephrine/pharmacology , Phosphodiesterase Inhibitors/chemistry , Rabbits , Radioligand Assay
11.
Clin Nephrol ; 44(5): 284-9, 1995 Nov.
Article in English | MEDLINE | ID: mdl-8605707

ABSTRACT

When loss of graft function occurs more than six months after transplantation, allograft nephrectomy is not routinely performed at the time of graft failure. It is usually performed only on those patients who subsequently develop specific complications. However, little is known about the characteristics that make patients more likely to require allograft nephrectomy. The purpose of our study was to identify risk factors for the subsequent need for allograft nephrectomy in patients with graft failure occurring more than 6 months after transplantation. Forty-one patients were studied. Inclusion criteria were: loss of graft function > or = 6 months after transplantation, resumption of dialysis and initiation of weaning from immunosuppression. Thirty patients were treated with cyclosporine + prednisone +/- azathioprine and 11 with azathioprine + prednisone. Mean follow-up time was 17.8 months, ranging from 6 months to 6.1 years. Recipient age, sex and race, original renal disease, donor, donor source (cadaveric vs living related), HLA compatibility, levels of panel reactive antibodies, occurrence of initial delayed graft function, causes of graft failure and tapering of immunosuppression were similar in patients with and without allograft nephrectomy. Using univariate analysis, allograft nephrectomy was found to be significantly more frequent in patients with a history of 2 or more episodes of acute rejection than in patients with no rejection episode: 83% vs 30% (p = 0.03). In addition, allograft nephrectomy was found to be significantly more frequent if the immunosuppressive regimen included cyclosporine (62% vs 27.3%; p = 0.04). Using multivariate analysis however, the number of previous episodes of rejection was found to be the only significant predictor for allograft nephrectomy. None of the other variables considered in the multivariate analysis, including the type of immunosuppressive therapy, was identified as a significant predictor for the need to perform allograft nephrectomy. In summary, the need for late allograft nephrectomy was correlated with the number of previous episodes of acute rejection. Patients with a history of numerous rejection episodes should thus be considered more likely to require allograft nephrectomy once immunosuppression is withdrawn. Possible interventions to reduce or prevent the need for nephrectomy include more gradual tapering of immunosuppression at the time of graft failure or indefinite low-dose immunosuppressive therapy.


Subject(s)
Graft Rejection/surgery , Kidney Transplantation/immunology , Nephrectomy , Adult , Female , Follow-Up Studies , Graft Rejection/prevention & control , Humans , Immunosuppressive Agents/therapeutic use , Male , Retrospective Studies , Risk Factors
12.
J Pharmacol Exp Ther ; 265(3): 1142-51, 1993 Jun.
Article in English | MEDLINE | ID: mdl-8389853

ABSTRACT

The distribution of phosphodiesterase (PDE) activities was studied in canine cardiac microsomal fractions separated by sucrose density gradient (fractions F1 to Fv1). These fractions were characterized by their 45Ca2+ uptake and release properties, [3H] ryanodine binding [used as sarcoplasmic reticulum (SR) markers] and their [3H]nitrendipine binding (as a T-system marker). The solubilized canine and human SR-enriched membranes were subjected to high performance liquid chromatography and the PDE forms were then analyzed for their kinetic properties and drug sensitivies. In human SR, a notable amount of PDE I hydrolyzing both cAMP and cGMP was characterized; however, its stimulation by calmodulin was reduced. Two selective cAMP-PDE forms were identified in the canine and human cardiac SR-enriched fractions. The major form presents the characteristics of PDE III: an apparent Km value of 0.29 and 0.35 microM in canine and human cardiac SR, respectively, potent inhibition by cGMP and AAL 05 > cilostamide > Cl 930 > indolidan, and insensitivity to rolipram. The other form displays the properties of PDE IV: an apparent Km value of 1.4 and 1.3 microM in canine and human cardiac SR respectively, potent inhibition by rolipram and poorly sensitive to inhibition by PDE III inhibitors. The PDE IV distribution in canine SR suggests that this form is mostly associated with the FII fraction enriched in sarcolemmal membranes. In contrast, PDE III assessed by its indolidan sensitivity and [3H]LY186126 binding is associated with the microsomal membranes enriched in vesicles derived from T-tubule and junctional SR membranes. Because these membranes are directly involved in controlling excitation-contraction coupling, such PDE location enhances the physiologic relevance to study their implication in regulating cardiac contraction.


Subject(s)
Indoles/pharmacology , Microsomes/enzymology , Myocardium/enzymology , Phosphoric Diester Hydrolases/metabolism , Pyridazines/pharmacology , Pyrrolidinones/pharmacology , 3',5'-Cyclic-AMP Phosphodiesterases/metabolism , Animals , Cardiotonic Agents/pharmacology , Chromatography, High Pressure Liquid , Dogs , Humans , In Vitro Techniques , Indoles/metabolism , Intracellular Membranes/metabolism , Kinetics , Oxindoles , Phosphodiesterase Inhibitors/pharmacology , Pyridazines/metabolism , Rolipram , Sarcoplasmic Reticulum/enzymology
13.
Can Assoc Radiol J ; 43(5): 381-4, 1992 Oct.
Article in English | MEDLINE | ID: mdl-1393706

ABSTRACT

The authors describe a patient with a rare type of renal arteriovenous malformation, which was successfully treated by therapeutic coil embolization. Embolization did not destroy healthy renal tissue, as was shown by the Cerino technique, which measures the glomerular filtration rate of each kidney by image processing for standard renograms obtained after administration of diethylene-triaminepenta-acetic acid labelled with technetium 99m.


Subject(s)
Arteriovenous Malformations/diagnostic imaging , Embolization, Therapeutic , Renal Artery/abnormalities , Renal Artery/diagnostic imaging , Arteriovenous Malformations/therapy , Female , Humans , Middle Aged , Radionuclide Imaging
14.
Mol Cell Biochem ; 114(1-2): 109-17, 1992 Sep 08.
Article in English | MEDLINE | ID: mdl-1281262

ABSTRACT

In order to study the conductances of the Sarcoplasmic Reticulum (SR) membrane, microsomal fractions from cardiac SR were isolated by differential and sucrose gradient centrifugations and fused into planar lipid bilayers (PLB) made of phospholipids. Using either KCl or K-gluconate solutions, a large conducting K+ selective channel was characterized by its ohmic conductance (152 pS in 150 mM K+), and the presence of short and long lasting subconducting states. Its open probability Po increased with depolarizing voltages, thus supporting the idea that this channel might allow counter-charge movements of monovalent cations during rapid SR Ca2+ release. An heterogeneity in the kinetic behavior of this channel would suggest that the cardiac SR K+ channels might be regulated by cytoplasmic, luminal, or intra SR membrane biochemical mechanisms. Since the behavior was not modified by variations of [Ca2+] nor by the addition of soluble metabolites such as ATP, GTP, cAMP, cGMP, nor by phosphorylation conditions on both sides of the PLB, a specific interaction with a SR membrane component is postulated. Another cation selective channel was studied in asymmetric Ca2+, Ba2+ or Mg(2+)-HEPES buffers. This channel displayed large conductance values for the above divalent cations 90, 100, and 40 pS, respectively. This channel was activated by microM Ca2+ while its Ca2+ sensitivity was potentiated by millimolar ATP. However Mg2+ and calmodulin modulated its gating behavior. Ca2+ releasing drugs such as caffeine and ryanodine increased its Po. All these features are characteristics of the SR Ca2+ release channel. The ryanodine receptor which has been purified and reconstituted into PLB, may form a cation selective pathway.(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Ion Channels/physiology , Myocardium/metabolism , Sarcoplasmic Reticulum/metabolism , Adenosine Triphosphate/physiology , Animals , Calcium Channels/physiology , Dogs , Electric Conductivity , In Vitro Techniques , Ion Channel Gating , Membrane Potentials , Myocardium/chemistry , Potassium Channels/physiology , Receptors, Cholinergic/physiology , Ryanodine Receptor Calcium Release Channel
16.
Gen Comp Endocrinol ; 53(1): 116-25, 1984 Jan.
Article in English | MEDLINE | ID: mdl-6232168

ABSTRACT

An aldosterone receptor in the cytosol from kidney of chick embryos which had a sedimentation coefficient of 8.2 S and a molecular weight higher than 100,000 was identified. Kinetic analysis at 4 degrees revealed a rapid association of the hormone to the receptor that followed second-order reaction kinetics and a dissociation of pseudo-first-order reaction kinetics. The association (ka) and dissociation (kd) rate constants were, respectively, 4.94 X 10(5) M-1 sec-1 and 8.33 X 10(-6) sec-1. From their ratio a KA value of 5.9 X 10(10) M-1 was calculated. In a series of experiments performed with kidneys of 17-day-old embryos, the KA at equilibrium, obtained from the Scatchard plot, was 3.1 +/- 1.2 X 10(8) M-1, whereas the Nmax was 172 +/- 14 fmol/mg protein. Competition studies with various steroids demonstrated that corticosterone had an affinity for the receptor close to that of aldosterone, thus suggesting a degree of resemblance of the mineralo- and glucocorticoid receptors in the chick embryo. However, the profiles of the binding affinities and capacities during the embryogenesis showed that the aldosterone-binding sites had a pattern completely different from that of the glucocorticoid receptor, indicating that the two receptors are most likely separate entities.


Subject(s)
Aldosterone/metabolism , Chick Embryo/metabolism , Kidney/metabolism , Receptors, Glucocorticoid/metabolism , Receptors, Steroid/metabolism , Animals , Binding, Competitive/drug effects , Chromatography, Gel , Dexamethasone/metabolism , Glucocorticoids/metabolism , Kidney/embryology , Kinetics , Models, Biological , Molecular Weight , Receptors, Mineralocorticoid
17.
J Urol ; 130(6): 1183-5, 1983 Dec.
Article in English | MEDLINE | ID: mdl-6315969

ABSTRACT

We report 2 cases of nephrogenic adenoma several years after successful cadaver kidney transplantation. In 1 case the lesion had cytomegalovirus inclusions, and we observed a marked and sustained reduction in the extension of the lesion with cessation of azathioprine. Surgical trauma and cytomegalovirus infections are discussed as etiologic factors. Conservative treatment seemed appropriate.


Subject(s)
Adenoma/etiology , Azathioprine , Cytomegalovirus Infections/complications , Intraoperative Complications , Kidney Transplantation , Urinary Bladder Neoplasms/etiology , Urinary Bladder/injuries , Adult , Female , Humans , Middle Aged , Time Factors
18.
Gen Comp Endocrinol ; 50(2): 292-304, 1983 May.
Article in English | MEDLINE | ID: mdl-6862176

ABSTRACT

Cytosol from kidney of chick embryo (age 16-18 days) contained a corticosterone-binding site with the features of a putative receptor. This receptor was a thermolabile protein, readily digested by proteolytic enzymes, with a sedimentation coefficient of 7-8 S and with an apparent molecular weight greater than 100,000. Simultaneous studies with transcortin (CBG) revealed several differences between the renal- and serum-binding protein pertaining to the effect of temperature, the sedimentation coefficient, the charcoal "stripping" and, finally, the binding and competition of various steroids for the two proteins. Kinetic analysis showed a rapid association (10 min), which followed second-order reaction kinetics, and a dissociation of pseudo-first-order reaction kinetics with a t1/2 of 168 min at 0 degrees. The analysis of the Scatchard plot showed the presence of a single class of binding sites with an association constant (KA) of 1.3 X 10(8)M-1 and a binding capacity (nmax) of 500-700 fmol/mg protein. We obtained similar results when we used dexamethasone as a ligand. The association (ka) and dissociation (kd) rate constants were respectively 2.9 X 10(6)M-1 sec-1 and 6.86 X 10(-5) sec-1. From their ratio a KA value of 4.2 X 10(10) M-1 was obtained. Studies with various steroids demonstrated that only dexamethasone and, to a lesser degree, progesterone competed for the binding site. These data showed that the kidney of chick embryo possessed one type of receptor for the glucocorticoids, which was similar to the type II described in rat kidney.


Subject(s)
Kidney/metabolism , Receptors, Glucocorticoid/metabolism , Receptors, Steroid/metabolism , Animals , Chick Embryo , Corticosterone/metabolism , Cytosol/metabolism , Dexamethasone/metabolism , Kidney/embryology , Kinetics , Molecular Weight , Temperature , Transcortin/metabolism
19.
Gen Comp Endocrinol ; 50(2): 305-12, 1983 May.
Article in English | MEDLINE | ID: mdl-6862177

ABSTRACT

In this study the ontogeny of cytosol receptors for corticosterone in the chick embryo kidney was examined and then this ontogenic profile was compared with that of an index of cellular development, i.e., the enzyme ornithine decarboxylase (ODC). The corticosterone receptor concentration (nmax) increased by sevenfold from Day 12 to Day 15 of embryogenesis and then declined to its lowest level by the time of hatching (Day 21). Similar results were obtained when dexamethasone was used as ligand, except that the baseline values at Day 9 and 21 were higher than those found with corticosterone. An identical ontogenic profile was obtained when the results were corrected for the endogenous glucocorticoids present in the cytosol. This increase of the corticosterone receptor occurred simultaneously with the enhanced adrenal corticoid synthesis. The ODC also showed a marked increase and a rapid fall during chick embryogenesis, but the enzyme activity was at its maximum when the corticosterone receptor number was still low (Days 12 and 13) and quickly decreased by the time the receptors had reached their highest levels (Days 14 and 15). The lowest level of ODC was observed immediately before hatching. These results indicate that during chick embryogenesis adrenal corticoids may induce the development of the corticosteroid receptor and that such development may cause a suppression of ODC activity. This suppressive effect of glucocorticoids could represent a mechanism of hormonal action on the kidney.


Subject(s)
Kidney/embryology , Receptors, Glucocorticoid/metabolism , Receptors, Steroid/metabolism , Age Factors , Animals , Chick Embryo , Dexamethasone/metabolism , Kidney/enzymology , Kidney/metabolism , Ornithine Decarboxylase/metabolism
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