Walter H. Lewis

Bio: Walter H. Lewis is an academic researcher from Washington University in St. Louis. The author has contributed to research in topics: Pollen & Plant ecology. The author has an hindex of 24, co-authored 85 publications receiving 2476 citations. Previous affiliations of Walter H. Lewis include Missouri Botanical Garden.

Medical Botany: Plants Affecting Man's Health

Abstract: Proprietary Registered and Trademark Names and Owners. Preface. Acknowledgements. 1. Introduction. 2. Complementary and Alternative Medicine. PART I: INJURIOUS PLANTS. 3. Internal Poisons. 4. Immune System and Cell Modifiers. 5. Allergies. PART II: REMEDIAL PLANTS. 6. Cancer. 7. Musculoskeletal System. 8. Peripheral Nervous System. 9. Heart and Circulation. 10. Metabolism. 11. Sensory Organs: Eye and Ear. 12. Oral Hygiene. 13. Gastrointestinal Tract. 14. Respiratory System. 15. Urogenital System. 16. Skin. 17. Deterrents: Antibiotics, Antiseptics, Pesticides, and Herbicides. 18. Panaceas, Adaptogens, and Tonics. PART III: PSYCHOACTIVE PLANTS. 19. Central Nervous System and Psychiatry. 20. Stimulants. 21. Hallucinogens. 22. Depressants. Appendix A: Outline Classification of Plants. Appendix B: Bibliography of Traditional and Herbal Medicine and Ethnobotany. Glossary. Index.

Drug Targeting Mycobacterium tuberculosis Cell Wall Synthesis: Genetics of dTDP-Rhamnose Synthetic Enzymes and Development of a Microtiter Plate-Based Screen for Inhibitors of Conversion of dTDP-Glucose to dTDP-Rhamnose

Abstract: An L-rhamnosyl residue plays an essential structural role in the cell wall of Mycobacterium tuberculosis. Therefore, the four enzymes (RmlA to RmlD) that form dTDP-rhamnose from dTTP and glucose-1-phosphate are important targets for the development of new tuberculosis therapeutics. M. tuberculosis genes encoding RmlA, RmlC, and RmlD have been identified and expressed in Escherichia coli. It is shown here that genes for only one isotype each of RmlA to RmlD are present in the M. tuberculosis genome. The gene for RmlB is Rv3464. Rv3264c was shown to encode ManB, not a second isotype of RmlA. Using recombinant RmlB, -C, and -D enzymes, a microtiter plate assay was developed to screen for inhibitors of the formation of dTDP-rhamnose. The three enzymes were incubated with dTDP-glucose and NADPH to form dTDP-rhamnose and NADP(+) with a concomitant decrease in optical density at 340 nm (OD(340)). Inhibitor candidates were monitored for their ability to lower the rate of OD(340) change. To test the robustness and practicality of the assay, a chemical library of 8,000 compounds was screened. Eleven inhibitors active at 10 microM were identified; four of these showed activities against whole M. tuberculosis cells, with MICs from 128 to 16 microg/ml. A rhodanine structural motif was present in three of the enzyme inhibitors, and two of these showed activity against whole M. tuberculosis cells. The enzyme assay was used to screen 60 Peruvian plant extracts known to inhibit the growth of M. tuberculosis in culture; two extracts were active inhibitors in the enzyme assay at concentrations of less than 2 microg/ml.

Polyploidy in Angiosperms: Dicotyledons

Abstract: As summarized by Goldblatt (1) in the previous article, “Polyploidy in angiosperms: monocotyledons,” recent estimates of polyploid frequency among angiosperms vary from 30–35% to 47%. The highest value is based on the postulation that haploid numbers in excess of n=13 would be mainly polyploid and those with n=13 or less would be predominantly diploid (2). On this basis 43% of dicotyledons and 58% of monocotyledons from a sample of 17,138 species were considered polyploid. Goldblatt (1) believes, however, that limiting Polyploidy to haploid numbers over n=13 is too conservative and that at least species with numbers of n=ll and above have Polyploidy in their evolutionary history, and perhaps also many of those with n=10 and n=9 may be aneuploid derivatives of ancestors with higher numbers. He suggests that at least 70% and most likely above 80% of monocotyledons are in some sense polyploid.

Plant Products as Antimicrobial Agents

Abstract: The use of and search for drugs and dietary supplements derived from plants have accelerated in recent years. Ethnopharmacologists, botanists, microbiologists, and natural-products chemists are combing the Earth for phytochemicals and “leads” which could be developed for treatment of infectious diseases. While 25 to 50% of current pharmaceuticals are derived from plants, none are used as antimicrobials. Traditional healers have long used plants to prevent or cure infectious conditions; Western medicine is trying to duplicate their successes. Plants are rich in a wide variety of secondary metabolites, such as tannins, terpenoids, alkaloids, and flavonoids, which have been found in vitro to have antimicrobial properties. This review attempts to summarize the current status of botanical screening efforts, as well as in vivo studies of their effectiveness and toxicity. The structure and antimicrobial properties of phytochemicals are also addressed. Since many of these compounds are currently available as unregulated botanical preparations and their use by the public is increasing rapidly, clinicians need to consider the consequences of patients self-medicating with these preparations.

The value of plants used in traditional medicine for drug discovery.

Abstract: In this review we describe and discuss several approaches to selecting higher plants as candidates for drug development with the greatest possibility of success. We emphasize the role of information derived from various systems of traditional medicine (ethnomedicine) and its utility for drug discovery purposes. We have identified 122 compounds of defined structure, obtained from only 94 species of plants, that are used globally as drugs and demonstrate that 80% of these have had an ethnomedical use identical or related to the current use of the active elements of the plant. We identify and discuss advantages and disadvantages of using plants as starting points for drug development, specifically those used in traditional medicine.

Allergen immunotherapy: A practice parameter third update

Abstract: These parameters were developed by the Joint Task Force on Practice Parameters, representing the American Academy of Allergy, Asthma & Immunology (AAAAI); the American Col- lege of Allergy, Asthma & Immunology (ACAAI); and the Joint Council of Allergy, Asthma & Immunology. The American Academy of Allergy, Asthma & Immunology and the American College of Allergy, Asthma & Immunology have jointly accepted responsibility for establishing ''Allergen immunotherapy: A practice parameter third update.'' This is a complete and com- prehensive document at the current time. The medical environ- ment is a changing environment, and not all recommendations will be appropriate for all patients. Because this document incorporated the efforts of many participants, no single individ- ual, including those who served on the Joint Task Force, is authorizedtoprovideanofficial AAAAIorACAAIinterpretation ofthesepracticeparameters.Anyrequestforinformationaboutor an interpretation of these practice parameters by the AAAAI or the ACAAI should be directed to the Executive Offices of the AAAAI, the ACAAI, and the Joint Council of Allergy, Asthma & Immunology. These parameters are not designed for use by pharmaceutical companies in drug promotion. A current list of published practice parameters of the Joint Task Force on Practice ParametersforAllergyandImmunologycanbefoundinTableE1 in this article's Online Repository at www.jacionline.org. Disclosure ofpotentialconflictofinterest:L.Coxisaconsultant forGenentech/Novartis, Hollister-Stier, and Stallergenes; is a speaker for Novartis; has received research support from Stallergenes; is on the Board of Directors for the American Board of Allergy and Immunology; and is on the US Food and Drug Administration (FDA)'s Allergenic Product Advisory Committee. H. Nelson is a consultant for Merck and Planet Biopharmaceuticals, is a Data and Safety Monitoring Board member of DBV Technologies, and has received research support from ALK-AbellM. Nelson has re- ceivedresearchsupportfromtheDepartmentofDefense,isaspeakerfortheAmerican College of Allergy, Asthma & Immunology (ACAAI), and is a member of the FDA's AdvisoryCommitteeonAllergicProducts.R.Weberisonthespeakers'bureauforAs- traZeneca and Genentech, has received research support from Novartis and Glaxo- SmithKline, and is Committee Chair of the ACAAI. D. I. Bernstein is a consultant and on the advisory board for ALK America, is on the advisory board for Merck, and has received research support from Merck and Schering-Plough. J. Blessing- Moore is a speaker for Merck-Schering/AstraZeneca, Novartis, TEVA, and Meda Alcon and has received research support from Meda. D. A. Khan is a speaker for As- traZeneca and Merck, has received research support from the Vanberg Family Foun- dation and the Sellars Family Foundation, is Conjoint Board Review Chair for the ACAAI,andisapastpresidentoftheTexasAllergy,AsthmaandImmunologySociety. D. M. Lang is a speaker and consultant for GlaxoSmithKline; is a speaker for Astra- Zeneca, Merck, TEVA, Sanofi-Aventis, and Genentech/Novartis; and has received re- search support from Genentech/Novartis. R. A. Nicklas is a fellow for the ACAAI. J. Oppenheimer is a consultant and has provided lectures for AstraZeneca, Merck, and GlaxoSmithKline; and has received research support from AstraZeneca, Merck, Glax- oSmithKline, and Genentech. J. M. Portnoy is a speaker for Phadia, Merck, and CSL Behring; hasreceived researchsupportfromtheUSDepartment ofHousingandUrban Development;andisa board memberof theACAAI board of regents.S.L. Spector has received research support from Genentech, GlaxoSmithKline, Schering-Plough, Aventis, Novartis, Pharmaxis, Boehringer Ingelheim, AstraZeneca, Johnson & John- son, Xyzal, Alcon, Centocor, Sepracor, UCB, Amgen, Capnia, and IVAX. S. Tilles isaspeakerforAlcon; isontheadvisoryboard forALK,Ista,Merck,andStallergenes; has received research support from Alcon, Amgen, Amphastar, Astellas, Boehringer Ingelheim,Ception,Genentech,Icagen, MAP Pharma, MEDA, Merck, Novartis, Rox- ane, and Sepracor; is Associate Editor of Allergy Watchand Annals of Allergy; and is a task force member for the Joint Task Force for Practice Parameters. D. Wallace is a speaker and advisor for Alcon, is a speaker for Merck and Sanofi-Aventis, and is President-Elect of the ACAAI. The rest of the authors have declared that they have no conflict of interest.