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Biomedical subjects

M Moore

Publications and source records attributed to M Moore.

At least 127 records · Page 7Linked to original sources

Respective role of TNF receptors in the development of experimental cerebral malaria.

The respective role of the two receptors of TNF in experimental cerebral malaria (CM) was investigated. During CM, a significant upregulation of TNF-receptor 2 (TNFR2), but not of TNFR1, was found in brain microvessels of susceptible, but not resistant mice. Mice genetically deficient for TNFR2 (Tnfr2null) were significantly protected from CM, while TNFR1-deficient (Tfnr1null) mice were as susceptible as wild-type mice. The protection of Tnfr2null mice could be explained by their absence of ICAM-1 upregulation and leukocyte sequestration, known to occur in brain microvessels of CM-susceptible animals.

Animals↗

Differential effects on TNF alpha production by pharmacological agents with varying molecular sites of action.

This study describes the activation conditions for tumor necrosis factor-alpha (TNF alpha) production in myelomonocytic U937 cells and human primary peripheral blood monocytes in response to lipopolysaccharide (LPS) and/or phorbol 12-myristate 13-acetate (PMA). PMA itself induced only low levels of TNF alpha production with delayed kinetics (e.g. 0.758 +/- 0.128 ng/ml from U937 cells after 48 h) while LPS induced greater levels of TNF alpha production in less time (e.g. 2.083 +/- 0.96 ng/ml from monocytes in 24 h). Pharmacological agents with various molecular sites of action were used to validate the two systems, with the protein serine-threonine kinase inhibitors staurosporine and Ro-31-8220, the protein tyrosine kinase inhibitor herbimycin A (HBA) and dexamethasone exhibiting the greatest potency (IC50S 5-350 nM). In contrast to the effect on TNF alpha production, PMA induced strong phosphorylation/activation of p42/p44mapk in monocytes by 10 min determined in a mobility shift assay, while LPS was a weaker inducer. Additionally, staurosporine (to LPS and PMA) and HBA (to LPS only) inhibited the activation of these mitogen-activated protein kinase (MAPK) isoforms at doses 10-100 fold higher than those required to inhibit maximal TNF alpha production. These data indicate the involvement of the p42/p44mapk signalling pathway in LPS-induced pro-inflammatory cytokine production but suggest that other signalling pathways are also implicated in this phenomenon.

Benzoquinones↗

Will natural products remain an important source of drug research for the future?

In the highly competitive environment of contemporary pharmaceutical research, natural products provide a unique element of molecular diversity and biological functionality which is indispensable for drug discovery. The emergence of strategies to deliver drug leads from natural products within the same time frame as synthetic chemical screening has eliminated a major limitation of the past. At a more functional level, the application of molecular genetics techniques has permitted the manipulation of biosynthetic pathways for the generation of novel chemical species as well as rendering hitherto uncultivatable microorganisms accessible for secondary metabolite generation. These developments augur well for an industry confronted with the challenge of finding lead compounds directed at the plethora of new targets arising from genomics projects. The exploitation of structural chemical databases comprising a wide variety of chemotypes, in conjunction with databases on target genes and proteins, will facilitate the creation of new chemical entities through computational molecular modelling for pharmacological evaluation.

Biotechnology↗

Plasma membrane water permeability of cultured cells and epithelia measured by light microscopy with spatial filtering.

A method was developed to measure the osmotic water permeability (Pf) of plasma membranes in cell layers and applied to cells and epithelia expressing molecular water channels. It was found that the integrated intensity of monochromatic light in a phase contrast or dark field microscope was dependent on relative cell volume. For cells of different size and shape (Sf9, MDCK, CHO, A549, tracheal epithelia, BHK), increased cell volume was associated with decreased signal intensity; generally the signal decreased 10-20% for a twofold increase in cell volume. A theory relating signal intensity to relative cell volume was developed based on spatial filtering and changes in optical path length associated with cell volume changes. Theory predictions were confirmed by signal measurements of cell layers bathed in solutions of various osmolarities and refractive indices. The excellent signal-to-noise ratio of the transmitted light detection permitted measurement of cell volume changes of <1%. The method was applied to characterize transfected cells and tissues that natively express water channels. Pf in control Chinese hamster ovary cells was low (0.0012 cm/s at 23 degrees C) and increased more than fourfold upon stable transfection with aquaporins 1, 2, 4, or 5. Pf in apical and basolateral membranes in polarized epithelial cells grown on porous supports was measured. Pfbl and Pfap were 0.0011 and 0.0024 cm/s (MDCK cells), and 0.0039 and 0.0052 cm/s (human tracheal cells) at 23 degrees C. In intact toad urinary bladder, basolateral Pf was 0.036 cm/s and apical membrane Pf after vasopressin stimulation was 0.025 cm/s at 23 degrees C. The results establish light microscopy with spatial filtering as a technically simple and quantitative method to measure water permeability in cell layers and provide the first measurement of the apical and basolateral membrane permeabilities of several important epithelial cell types.

Animals↗

Alaska's statewide trauma registry: a useful surveillance tool for injury prevention planning and evaluation.

The state of Alaska is unique because it is one of a small number of states with a surveillance system that collects trauma information from every hospital in the state. The Alaska Trauma Registry (ATR) collects up to 144 data elements for every injured patient. Information from the ATR is useful as an injury surveillance tool for federal, state, and local governments and other agencies and organizations when planning and evaluating injury prevention programs. Combining trauma registry data with Bureau of Vital Statistics cause of death data provides complete, statewide, population-based data on all injuries serious enough to result in death or hospitalization.

Adolescent↗

Pharmacokinetics and metabolism of the novel anticonvulsant agent N-(2,6-dimethylphenyl)-5-methyl-3-isoxazolecarboxamide (D2624) in rats and humans.

N-(2,6-dimethylphenyl)-5-methyl-3-isoxazolecarboxamide (D2624) belongs to a new series of experimental anticonvulsants related to lidocaine. This study was undertaken to understand the pharmacokinetics and metabolism of D2624 in rats and humans, with emphasis on the possible formation of 2,6-dimethylaniline (2,6-DMA). After oral administration of stable isotope-labeled parent drug to rats and GC/MS analysis of plasma samples, two metabolites were identified: D3017, which is the primary alcohol, and 2,6-DMA, formed by amide bond hydrolysis of either D2624 or D3017. In urine, three metabolites of D2624 were identified: namely D3017,2,6-DMA, and D3270 (which is the carboxylic acid derivative of D3017). Based on plasma AUC analysis, D3017 and 2,6-DMA accounted for > 90% of the dose of D2624. After oral administration, D2624 was found to be well absorbed (93%), but underwent extensive first-pass metabolism in the rat, thus resulting in 5.3% bioavailability. Rat and human liver microsomal preparations were capable of metabolizing D2624 to D3017 and 2,6-DMA. The formation of D3017 was NADPH-dependent, whereas 2,6-DMA formation was NADPH-independent and probably was catalyzed by amidase(s) enzymes. In a single-dose (25-225 mg) human volunteer study, the parent drug (D2624) was not detected in plasma at any dose, whereas 2,6-DMA was detected only at the two highest doses (150 and 225 mg). D3017 was detected after all doses of parent drug, with approximate dose proportionality in AUC and a half-life of 1.3-2.2 hr. The metabolic behavior observed in humans suggests there is a marked species difference in the oxidative and hydrolytic pathways of D2624.

Aniline Compounds↗

Prognostic factors for relapse in stage I testicular seminoma treated with surveillance.

PURPOSE: We sought to identify prognostic factors predictive of disease progression in patients with clinical stage I seminoma on surveillance following orchiectomy. MATERIALS AND METHODS: Between January 1981 and December 1993, 201 patients 20 to 86 years old (median age 34) with clinical stage I seminoma were placed on surveillance following orchiectomy. The potential prognostic factors studied included age, tumor size, mitotic count, S phase fraction, ploidy, presence of small vessel invasion, syncytiotrophoblasts and tumor infiltrating lymphocytes, expression of beta-human chorionic gonadotropin and low molecular weight keratin on immunohistochemistry. RESULTS: With a median followup of 6.1 years (range 1.3 to 12.3) 31 patients had relapse for an actuarial 5-year relapse-free rate of 84.9%. The 5-year actuarial survival rate was 97.1% and the cause specific survival rate was 99.5%. On univariate analysis factors predictive of relapse were tumor size (5-year relapse-free rate 88 and 67% for tumors 6 cm. or less and greater than 6 cm., respectively, p = 0.004), age (5-year relapse-free rate 79 and 91% for age 34 years or younger versus older than 34 years, respectively, p = 0.009) and presence of small vessel invasion (5-year relapse-free rate 86 versus 69%, p = 0.01). On multivariate analysis age and tumor size were predictive of relapse, while small vessel invasion approached statistical significance. The risk of relapse in 57 patients with none of the 3 adverse prognostic factors (age greater than 34 years, tumor 6 cm. or smaller and no small vessel invasion) was 6%. CONCLUSIONS: We identified age, size of the primary tumor and small vessel invasion as important prognostic factors for relapse in patients with stage I seminoma treated with surveillance. Further followup and assessment of biological factors are needed to optimize selection of patients at a high risk for relapse who should receive immediate postoperative therapy.

Actuarial Analysis↗

Management of hepatic artery injury: case report.

The trauma surgeon encounters hepatic arterial injury only rarely. The majority of these injuries appear to be due to penetrating trauma, with few cases of hepatic artery injury secondary to blunt trauma reported in the literature. In the setting of blunt trauma, hepatic artery injury is generally accompanied by other severe injuries, and mortality remains high. We present two patients who sustained an avulsion of the left hepatic artery complicating severe blunt trauma to the abdomen and pelvis. Surgical management included ligation of the involved vessel. Both patients required management in the intensive care unit, one eventually succumbing to multisystem organ failure. The cases highlight management principles in these injuries, and treatment options are discussed.

Abdominal Injuries↗

Contact lens use after corneal trauma.

BACKGROUND: This study was performed to explore the epidemiology and visual outcomes of major anterior segment trauma cases referred to the Contact Lens Service (CLS) in a large, urban, eye trauma center at a university hospital. METHODS: All eye trauma patients seen on the CLS at The University of Illinois in Chicago for a 2-year period were identified (n = 122). A search of all eye trauma cases seen at UIC (n = 2279) during the same period yielded 757 cases with the same diagnostic codes. RESULTS: CLS cases represent 16.1% of cases with similar diagnoses and 5.35% of all cases seen during the period of study. Cases were predominantly young men (mean age, 28 years). The mean age for CLS cases (mean age, 17 years) was significantly younger. Best-corrected visual acuity was 20/100 or better in 75% of cases with a contact lens and in 68% of cases with a spectacle lens; 82% of CLS cases had iris damage versus 14.5% of non-CLS cases; 73% of CLS cases were aphakic; 105 CLS cases were given contact lenses. Mean follow-up time was 24 months. Mean wearing time was 11 hours/day. On interview, 35 of 79 cases (44%) continued to wear lenses. CONCLUSIONS: Cases referred to the CLS tended to be young men with unilateral injuries-predominantly open globes-with resultant aphakia and iris damage. Good visual acuity was achieved in most cases. Long-term success wearing contact lenses for this population was poor, suggesting that alternatives to contact lens wear should be more actively considered.

Adolescent↗

The role of HIV counseling and testing in the developing world.

The role of voluntary HIV counseling and testing is still under debate, especially in the developing world. HIV counseling-and-testing (HIV CT) services are a major component of HIV and AIDS control programs in the industrialized world and are increasingly being advocated in the developing world. In the United States, voluntary HIV CT has been a major component of HIV prevention efforts since the HIV antibody test became available in 1985. Yet even in the United States, questions about the management, cost, and effectiveness of voluntary HIV CT services continue to be raised. Because HIV CT has multiple goals, the evaluation of its effectiveness is a complicated task. Worldwide, a broad range of ethical, social, policy, technical, and economic issues encompass this HIV prevention activity. This article identifies the substantial barriers and serious concerns that are raised about HIV CT services and attempts to highlight the potential advantages of providing HIV CT as part of a developing country's comprehensive HIV prevention strategy.

AIDS Serodiagnosis↗

Regulation of neuronal and recombinant GABA(A) receptor ion channels by xenovulene A, a natural product isolated from Acremonium strictum.

Xenovulene A (XR368) is a natural product exhibiting little structural resemblance with classical benzodiazepines yet is able to displace high-affinity ligand binding to the benzodiazepine site of the gamma-aminobutyric acid (GABA)A receptor. We have characterized this compound and an associated congener (XR7009) by use of radioligand binding and electrophysiological methodologies with native neurons and the Xenopus oocyte expression system. Xenovulene A, and the more potent XR7009, inhibited [3H]flunitrazepam binding to rat forebrain with Ki values of 7 and 192 nM, and 1.7 and 42 nM, respectively, each site accounting for approximately 50% of the total specific binding. In cerebellar and spinal cord membranes, these ligands identified only single binding sites. These ligands demonstrated no intrinsic agonist activity at recombinant GABA(A) receptors comprising alpha1beta1gamma2S subunits expressed in Xenopus oocytes, yet at 1 microM both significantly potentiated the GABA-induced response and reduced the GABA EC50 from 10.9 (control) to 5.1 (Xenovulene A) or 2.7 microM (XR7009). The rank potency order for enhancement of the 10 microM GABA response is: XR7009 (EC50, 0.02 microM) > diazepam (0.03) > Xenovulene A (0.05) > flurazepam (0.17). The activity of XR368 and XR7009 was reduced by the benzodiazepine antagonist, flumazenil, and absent in receptors devoid of the gamma2 subunit. These agents exhibited receptor subtype selectivity because alpha3beta1gamma2S receptors were less sensitive to these compounds relative to alpha1 subunit-containing receptors, whereas alpha6beta1gamma2S receptors were completely insensitive. Potentiation of the response to GABA on native GABA(A) receptors in cortical neurons substantiates the profile of the novel structures of Xenovulene A and XR7009 as specific benzodiazepine agonists.

Acremonium↗

Clinical experience with gemcitabine in pancreatic carcinoma.

The treatment of advanced pancreatic carcinoma has been viewed with pessimism. Because of the lack of activity of commonly used agents, there is no consensus regarding a standard chemotherapy regimen. Assessment of response is neither uniform nor reproducible. Debilitating tumor-related symptoms, including pain, anorexia, weight loss, and impaired performance status, are common. Many studies have failed to evaluate the palliative benefit of treatments, although many patients consider such benefit to be of the utmost importance. Tools have been developed to uniformly assess tumor-related symptoms, and the concept of clinical benefit response has been developed as an end point to quantify symptomatic improvement utilizing these tools. Clinical benefit response incorporates palliative measures, such as pain control, analgesic consumption, performance status, and weight gain. In early phase I and II trials, gemcitabine (Gemzar) has shown activity in patients with chemotherapynaive advanced pancreatic carcinoma. In addition to producing some responses and symptomatic benefit, gemcitabine has a favorable toxicity profile. Two recent trials using clinical benefit response as the primary end point have demonstrated that gemcitabine significantly improves disease-related symptoms in approximately one-quarter of patients. These trials also showed improved survival with gemcitabine, as compared with fluorouracil. Additional studies are required to fully assess the role of gemcitabine in both adjuvant and advanced disease settings.

Adenocarcinoma↗

Sore throat.

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Anti-Bacterial Agents↗