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Biomedical subjects

J M Moore

Publications and source records attributed to J M Moore.

At least 37 records · Page 2Linked to original sources

Chronic prenatal cocaine treatment down-regulates mu-opioid receptor mRNA expression in the brain of fetal Rhesus Macaque.

Ribonuclease protection assays (RPA) were performed to quantify mu-opioid receptor mRNA expression in specific brain regions of day 70 Rhesus Macaque fetuses that were exposed to cocaine (3 mg/kg) or saline from days 22-70 of gestation. The content of mu-receptor mRNA was high in the diencephalon and moderate in the mesencephalon. In contrast, mu-receptor mRNA was lightly expressed in areas such as the frontal cortex, striatum and the temporal lobe. The content of mu-opioid receptor mRNA was significantly higher in the diencephalon than in other brain regions (P < 0.001; n = 4). Cocaine exposure significantly decreased the expression of mu-receptor mRNA in the fetal diencephalon (P < 0.05; n = 4 in each group). Our data would indicate that prolonged gestational cocaine exposure causes mu-opioid receptor mRNA down-regulation in specific brain regions of the fetus.

Animals↗

NMR techniques for characterization of ligand binding: utility for lead generation and optimization in drug discovery.

Over the last ten years, nmr spectroscopy has evolved into an important discipline in drug discovery. Initially, nmr was most useful as a technique to provide structural information regarding protein drug targets and target-ligand interactions. More recently, it has been shown that nmr may be used as an alternative method for identification of small molecule ligands that bind to protein drug targets. High throughput implementation of these experiments to screen small molecule libraries may lead to identification of potent and novel lead compounds. In this review, we will use examples from our own research to illustrate how nmr experiments to characterize ligand binding may be used to both screen for novel compounds during the process of lead generation, as well as provide structural information useful for lead optimization during the latter stages of a discovery program.

Binding Sites↗

NMR screening in drug discovery.

NMR methods in drug discovery have traditionally been used to obtain structural information for drug targets or target-ligand complexes. Recently, it has been shown that NMR may be used as an alternative approach for identification of ligands that bind to protein drug targets, shifting the emphasis of many NMR laboratories towards screening and design of potential drug molecules, rather than structural characterization.

Biotechnology↗

The SHAPES strategy: an NMR-based approach for lead generation in drug discovery.

BACKGROUND: Recently, it has been shown that nuclear magnetic resonance (NMR) may be used to identify ligands that bind to low molecular weight protein drug targets. Recognizing the utility of NMR as a very sensitive method for detecting binding, we have focused on developing alternative approaches that are applicable to larger molecular weight drug targets and do not require isotopic labeling. RESULTS: A new method for lead generation (SHAPES) is described that uses NMR to detect binding of a limited but diverse library of small molecules to a potential drug target. The compound scaffolds are derived from shapes most commonly found in known therapeutic agents. NMR detection of low (microM-mM) affinity binding is achieved using either differential line broadening or transferred NOE (nuclear Overhauser effect) NMR techniques. CONCLUSIONS: The SHAPES method for lead generation by NMR is useful for identifying potential lead classes of drugs early in a drug design program, and is easily integrated with other discovery tools such as virtual screening, high-throughput screening and combinatorial chemistry.

IMP Dehydrogenase↗

Immunity to placental malaria. I. Elevated production of interferon-gamma by placental blood mononuclear cells is associated with protection in an area with high transmission of malaria.

In areas in which malaria is holoendemic, primigravidae and secundigravidae, compared with multigravidae, are highly susceptible to placental malaria (PM). The nature of gravidity-dependent immune protection against PM was investigated by measuring in vitro production of cytokines by placental intervillous blood mononuclear cells (IVBMC). The results demonstrated that interferon (IFN)-gamma may be a critical factor in protection against PM: production of this cytokine by PM-negative multigravid IVBMC was elevated compared with PM-negative primigravid and secundigravid and PM-positive multigravid cells. Low IFN-gamma responsiveness to malarial antigen stimulation, most evident in the latter group, was balanced by increased interleukin (IL)-4 production, suggesting that counter-regulation of these two cytokines may be a crucial determinant in susceptibility to PM. A counter-regulatory relationship between IL-10 and tumor necrosis factor-alpha was also observed in response to malarial antigen stimulation. These data suggest that elevated production of IFN-gamma, as part of a carefully regulated cytokine network, is important in the control of PM.

Adult↗

Dose-response effects of spinal neostigmine added to bupivacaine spinal anesthesia in volunteers.

BACKGROUND: Intrathecal adjuncts often are used to enhance small-dose spinal bupivacaine for ambulatory anesthesia. Neostigmine is a novel spinal analgesic that could be a useful adjunct, but no data exist to assess the effects of neostigmine on small-dose bupivacaine spinal anesthesia. METHODS: Eighteen volunteers received two bupivacaine spinal anesthetics (7.5 mg) in a randomized, double-blinded, crossover design. Dextrose, 5% (1 ml), was added to one spinal infusion and 6.25, 12.5, or 50 microg neostigmine in dextrose, 5%, was added to the other spinal. Sensory block was assessed with pinprick; by the duration of tolerance to electric stimulation equivalent to surgical incision at the pubis, knee, and ankle; and by the duration of tolerance to thigh tourniquet. Motor block at the quadriceps was assessed with surface electromyography. Side effects (nausea, vomiting, pruritus, and sedation) were noted. Hemodynamic and respiratory parameters were recorded every 5 min. Dose-response relations were assessed with analysis of variance, paired t tests, or Spearman rank correlation. RESULTS: The addition of 50 microg neostigmine significantly increased the duration of sensory and motor block and the time until discharge criteria were achieved. The addition of neostigmine produced dose-dependent nausea (33-67%) and vomiting (17-50%). Neostigmine at these doses had no effect on hemodynamic or respiratory parameters. CONCLUSIONS: The addition of 50 microg neostigmine prolonged the duration of sensory and motor block. However, high incidences of side effects and delayed recovery from anesthesia with the addition of 6.25 to 50 microg neostigmine may limit the clinical use of these doses for outpatient spinal anesthesia.

Adult↗

Comparison of three solutions of ropivacaine/fentanyl for postoperative patient-controlled epidural analgesia.

BACKGROUND: Ropivacaine, 0.2%, is a new local anesthetic approved for epidural analgesia. The addition of 4 microg/ml fentanyl improves analgesia from epidural ropivacaine. Use of a lower concentration of ropivacaine-fentanyl may further improve analgesia or decrease side effects. METHODS: Thirty patients undergoing lower abdominal surgery were randomized in a double-blinded manner to receive one of three solutions: 0.2% ropivacaine-4 microg fentanyl 0.1% ropivacaine-2 microg fentanyl, or 0.05% ropivacaine-1 microg fentanyl for patient-controlled epidural analgesia after standardized combined epidural and general anesthesia. Patient-controlled epidural analgesia settings and adjustments for the three solutions were standardized to deliver equivalent drug doses. Pain scores (rest, cough, and ambulation), side effects (nausea, pruritus, sedation, motor block, hypotension, and orthostasis), and patient-controlled epidural analgesia consumption were measured for 48 h. RESULTS: All three solutions produced equivalent analgesia. Motor block was significantly more common (30 vs. 0%) and more intense with the 0.2% ropivacaine-4 microg fentanyl solution. Other side effects were equivalent between solutions and mild in severity. A significantly smaller volume of 0.2% ropivacaine-4 microg fentanyl solution was used, whereas the 0.1% ropivacaine-2 microg fentanyl group used a significantly greater amount of ropivacaine and fentanyl. CONCLUSIONS: Lesser concentrations of ropivacaine and fentanyl provide comparable analgesia with less motor block despite the use of similar amounts of ropivacaine and fentanyl. This finding suggests that concentration of local anesthetic solution at low doses is a primary determinant of motor block with patient-controlled epidural analgesia after lower abdominal surgery.

Amides↗

Designing an effective statewide tobacco control program--Oregon.

In this report, the author documents the first stages in the development and implementation of Oregon's tobacco control program. She briefly reviews the history of tobacco control coalitions in Oregon prior to the passage of Ballot Measure 44 and attributes much of the success to earlier coalition-building efforts.

Communication↗

Designing an effective counteradvertising campaign--Oregon.

In this report, the authors describe the key components for development of the soon to be created counteradvertising campaign. Emphasis is placed on numerous factors, including training, selection of target groups, the need for multiple media channels, and scientific assessment of media strategies.

Advertising↗

Postpartum coma.

Explore the source record for details and available documents.

Coma↗

Are we underestimating rates of vaginal birth after previous cesarean birth? The validity of delivery methods from birth certificates.

Previous studies of birth certificates have not fully evaluated how accurately they identify delivery methods that have a historical component, such as repeat cesarean and vaginal birth after previous cesarean (VBAC). The authors used linked Georgia birth certificates for first and second deliveries to examine the accuracy of four reported delivery methods in the second pregnancy: vaginal (without previous cesarean), VBAC, primary cesarean, and repeat cesarean, as well as an indicator of a previous cesarean. From the immediate birth certificates, the delivery method for each of the two births was classified as vaginal (V) or cesarean section (CS), which produced possible sequences of V-V, CS-V, V-CS, and CS-CS. The delivery method for the second births to 106,049 women from 1989 through 1992 was reviewed, taking into account the historical information from the linked certificates regarding the first births. Only 42.0% of women with a CS-V sequence were correctly designated on the second birth certificate as a VBAC; 79.3% of women with a V- CS sequence were correctly designated as primary cesarean. From 1980 through 1988, birth certificates contained a check box indicating a previous cesarean (but no VBAC box). During this period, only 75.5% of 25,491 women with a previous cesarean were so designated on the birth certificate. These findings suggest that cross-sectional vital records data substantially underestimate VBAC and primary cesarean rates.

Birth Certificates↗

Geological evidence for solid-state convection in Europa's ice shell.

The ice-rich surface of the jovian satellite Europa is sparsely cratered, suggesting that this moon might be geologically active today. Moreover, models of the satellite's interior indicate that tidal interactions with Jupiter might produce enough heat to maintain a subsurface liquid water layer. But the mechanisms of interior heat loss and resurfacing are currently unclear, as is the question of whether Europa has (or had at one time) a liquid water ocean. Here we report on the morphology and geological interpretation of distinct surface features-pits, domes and spots-discovered in high-resolution images of Europa obtained by the Galileo spacecraft. The features are interpreted as the surface manifestation of diapirs, relatively warm localized ice masses that have risen buoyantly through the subsurface. We find that the formation of the features can be explained by thermally induced solid-state convection within an ice shell, possibly overlying a liquid water layer. Our results are consistent with the possibility that Europa has a liquid water ocean beneath a surface layer of ice, but further tests and observations are needed to demonstrate this conclusively.

Extraterrestrial Environment↗

Angiotensin II type 2 receptor stimulation of neuronal delayed-rectifier potassium current involves phospholipase A2 and arachidonic acid.

Angiotensin II (Ang II) elicits an Ang II type 2 (AT2) receptor-mediated increase in delayed-rectifier K+ current (IK) in neurons cultured from newborn rat hypothalamus and brainstem. This effect involves a pertussis toxin (PTX)-sensitive Gi protein and is abolished by inhibition of serine and threonine phosphatase 2A (PP-2A). Here, we determined that Ang II stimulates [3H]arachidonic acid (AA) release from cultured neurons via AT2 receptors. This effect of Ang II was blocked by inhibition of phospholipase A2 (PLA2) and by PTX. Because AA and its metabolites are powerful modulators of neuronal K+ currents, we investigated the involvement of PLA2 and AA in the AT2 receptor-mediated stimulation of IK by Ang II. Single-cell reverse transcriptase (RT)-PCR analyses revealed the presence of PLA2 mRNA in neurons that responded to Ang II with an increase in IK. The stimulation of neuronal IK by Ang II was attenuated by selective inhibitors of PLA2 and was mimicked by application of AA to neurons. Inhibition of lipoxygenase (LO) enzymes significantly reduced both Ang II- and AA-stimulated IK, and the 12-LO metabolite of AA 12S-hydroxyeicosatetraenoic acid (12S-HETE) stimulated IK. These data indicate the involvement of a PLA2, AA, and LO metabolite intracellular pathway in the AT2 receptor-mediated stimulation of neuronal IK by Ang II. Furthermore, the demonstration that inhibition of PP-2A abolished the stimulatory effects of Ang II, AA, and 12S-HETE on neuronal IK but did not alter Ang II-stimulated [3H]-AA release suggests that PP-2A is a distal event in this pathway.

Angiotensin II↗

Capillary electrophoresis analysis of isomeric truxillines and other high molecular weight impurities in illicit cocaine.

The analysis of by-products and impurities in illicit cocaine, including the isomeric truxillines, is important for derivation of both strategic and tactical intelligence. In the present study, various capillary electrophoresis techniques were investigated for this purpose. The use of the anionic beta-cyclodextrin sulfobutyl ether IV as a run buffer additive at pH 8.6 gave a good separation of the truxillines and similar high molecular weight impurities in less than eight minutes. These impurities were first isolated from the bulk cocaine matrix using liquid-liquid extraction and size-exclusion high performance liquid chromatography. There was a red shift in the UV spectra obtained for the truxillines using photodiode array (PDA) UV detection during CE analysis. This anomalous behavior is attributed to photo-degradation of the truxillines during the PDA-UV irradiation process. Laser-induced fluorescence detection using a UV krypton/fluoride laser provided greater selectivity and sensitivity versus UV detection for certain uncharacterized high molecular weight impurities.

Cocaine↗

Microdrop screening: a rapid method to optimize solvent conditions for NMR spectroscopy of proteins.

Determining appropriate solvent conditions is a crucial first step for carrying out NMR spectroscopy of proteins, but rapid and efficient methods for doing so are currently lacking. Microdrop screening examines a large number of different solvent conditions using very small amounts of protein and minimal labor. Starting from one initial buffer condition, small aliquots of protein solution are combined with an array of solutions in which concentration, pH, buffer type, and added stabilizers are systematically varied. The protein concentration of each microliter-sized test drop ('microdrop') is gradually changed using vapor diffusion, and the solubility of the protein is determined by visual examination. A variety of analytical techniques may be applied to the contents of the microdrops to monitor enzymatic activity, aggregation, ligand binding, and protein folding.

Buffers↗

Selection of T-DNA-tagged male and female gametophytic mutants by segregation distortion in Arabidopsis.

As a strategy for the identification of T-DNA-tagged gametophytic mutants, we have used T-DNA insertional mutagenesis based on screening for distorted segregation ratios by antibiotic selection. Screening of approximately 1000 transgenic Arabidopsis families led to the isolation of eight lines showing reproducible segregation ratios of approximately 1:1, suggesting that these lines are putative gametophytic mutants caused by T-DNA insertion at a single locus. Genetic analysis of T-DNA transmission through reciprocal backcrosses with wild type showed severe reductions in genetic transmission of the T-DNA through the male and/or female gametes. Direct evidence for mutant phenotypes in these lines was investigated by DAPI staining of mature pollen grains and by the analysis of seed set and embryo sac morphology in cleared ovules. One line, termed limpet pollen, showed a novel pollen phenotype in that the generative cell failed to migrate inward after pollen mitosis I, such that the generative or sperm cells remained against the pollen wall. Two other lines, andarta and tistrya, were defective in female transmission and showed an early arrest of embryo sac development with the viable megaspore not initiating the nuclear division cycles. These data demonstrate the efficacy of a segregation ratio distortion strategy for the identification of T-DNA-tagged gametophytic mutants in Arabidopsis.

Arabidopsis↗

The effect of epinephrine on small-dose hyperbaric bupivacaine spinal anesthesia: clinical implications for ambulatory surgery.

UNLABELLED: The effect of adding epinephrine to small doses of spinal bupivacaine on the duration of sensory motor block has not been carefully investigated. Twelve volunteers underwent hyperbaric bupivacaine spinal anesthesia (7.5 mg) with and without epinephrine (0.2 mg) in a randomized, double-blind, cross-over fashion. Sensory block was assessed with pinprick, transcutaneous electrical stimulation (TES) equivalent to surgical stimulation (at umbilicus, pubis, knee, and ankle), and tolerance of a pneumatic thigh tourniquet. Motor block was assessed with isometric force dynamometry. Discharge criteria were defined as return of pinprick sensation to dermatome S2, ability to ambulate, and ability to urinate. Extent of sensory block to pinprick over time was unaffected by the addition of epinephrine. However, epinephrine prolonged tolerance of TES at the pubis, knee, and ankle (33-48 min, P < 0.05) and of thigh tourniquet (30 min, P < 0.01). Motor block was prolonged by epinephrine at the quadriceps and gastrocnemius muscles (by 23 and 51 min, respectively, P < 0.002). Achievement of discharge criteria was prolonged by 48 min by the addition of epinephrine (P < 0.01). Thus, epinephrine may prolong surgical anesthesia for lower abdominal and lower extremity surgery and delay time until patients achieve discharge criteria. IMPLICATIONS: Using a cross-over study design, 12 volunteers underwent bupivacaine spinal anesthesia with and without epinephrine. This study suggests that adding epinephrine to bupivacaine may prolong surgical anesthesia and also delay patients' discharge.

Adult↗