| U-Plasminogen Activator use Urokinase-Type Plasminogen Activator               | 
              | U1 Small Nuclear Ribonucleoproteins use Ribonucleoprotein, U1 Small Nuclear               | 
              | U1 snRNP use Ribonucleoprotein, U1 Small Nuclear               | 
              | U2 Small Nuclear Ribonucleoproteins use Ribonucleoprotein, U2 Small Nuclear               | 
              | U2 snRNP use Ribonucleoprotein, U2 Small Nuclear               | 
              | U4 Small Nuclear Ribonucleoproteins use Ribonucleoprotein, U4-U6 Small Nuclear               | 
              | U4 snRNP use Ribonucleoprotein, U4-U6 Small Nuclear               | 
              | U4-U6 Small Nuclear Ribonucleoproteins use Ribonucleoprotein, U4-U6 Small Nuclear               | 
              | U4-U6 snRNP use Ribonucleoprotein, U4-U6 Small Nuclear               | 
              | U5 Small Nuclear Ribonucleoproteins use Ribonucleoprotein, U5 Small Nuclear               | 
              | U5 snRNP use Ribonucleoprotein, U5 Small Nuclear               | 
              | U6 Small Nuclear Ribonucleoproteins use Ribonucleoprotein, U4-U6 Small Nuclear               | 
              | U6 snRNP use Ribonucleoprotein, U4-U6 Small Nuclear               | 
              | U7 Small Nuclear Ribonucleoproteins use Ribonucleoprotein, U7 Small Nuclear               | 
              | U7 snRNP use Ribonucleoprotein, U7 Small Nuclear               | 
              | U937 Cells               | 
              | Ubiquinol-Cytochrome-c Reductase use Electron Transport Complex III               | 
              | Ubiquinone               | 
              | Ubiquitin               | 
              | Ubiquitin C               | 
              | Ubiquitin Thiolesterase               | 
              | Ubiquitin-Activating Enzymes               | 
              | Ubiquitin-Conjugating Enzymes               | 
              | Ubiquitin-Like Proteins use Ubiquitins               | 
              | Ubiquitin-Protein Ligase use Ubiquitin-Protein Ligases               | 
              | Ubiquitin-Protein Ligase Complexes               | 
              | Ubiquitin-Protein Ligases               | 
              | Ubiquitination               | 
              | Ubiquitins               | 
              | Uca use Brachyura               | 
              | Udder use Mammary Glands, Animal               | 
              | UDP use Uridine Diphosphate               | 
              | UDP Acetylgalactosamine use Uridine Diphosphate N-Acetylgalactosamine               | 
              | UDP Acetylglucosamine use Uridine Diphosphate N-Acetylglucosamine               | 
              | UDP Acetylmuramic Acid use Uridine Diphosphate N-Acetylmuramic Acid               | 
              | UDP Galactose use Uridine Diphosphate Galactose               | 
              | UDP Galactose Acetylglucosamine Galactosyltransferase use N-Acetyllactosamine Synthase               | 
              | UDP Galactose Epimerase use UDPglucose 4-Epimerase               | 
              | UDP Galactose Pyrophosphorylase use UTP-Hexose-1-Phosphate Uridylyltransferase               | 
              | UDP Glucose use Uridine Diphosphate Glucose               | 
              | UDP Glucose Dehydrogenase use Uridine Diphosphate Glucose Dehydrogenase               | 
              | UDP Glucose Epimerase use UDPglucose 4-Epimerase               | 
              | UDP Glucose Pyrophosphorylase use UTP-Glucose-1-Phosphate Uridylyltransferase               | 
              | UDP Glucuronic Acid use Uridine Diphosphate Glucuronic Acid               | 
              | UDP Glucuronosyltransferase use Glucuronosyltransferase               | 
              | UDP Sugars use Uridine Diphosphate Sugars               | 
              | UDP Xylose use Uridine Diphosphate Xylose               | 
              | UDPG use Uridine Diphosphate Glucose               | 
              | UDPG Dehydrogenase use Uridine Diphosphate Glucose Dehydrogenase               | 
              | UDPGA use Uridine Diphosphate Glucuronic Acid               | 
              | UDPGal use Uridine Diphosphate Galactose               | 
              | UDPgalactose 4-Epimerase use UDPglucose 4-Epimerase               | 
              | UDPglucose 4-Epimerase               | 
              | UDPglucose 4-Epimerase Deficiency Disease use Galactosemias               | 
              | UDPglucose-Hexose-1-Phosphate Uridylyltransferase               | 
              | UDPglucose-Hexose-1-Phosphate Uridylyltransferase Deficiency use Galactosemias               | 
              | UDPGNAc use Uridine Diphosphate N-Acetylglucosamine               | 
              | Uganda               | 
              | Ukraine               | 
              | Ulcer               | 
              | Ulcer, Aphthous use Stomatitis, Aphthous               | 
              | Ulcer, Rodent use Carcinoma, Basal Cell               | 
              | Ulex               | 
              | Ulmaceae               | 
              | Ulmus               | 
              | Ulmus campestris               | 
              | Ulna               | 
              | Ulna Fractures               | 
              | Ulnar Artery               | 
              | Ulnar Nerve               | 
              | Ulnar Nerve Compression Syndromes               | 
              | Ulnar Nerve Diseases use Ulnar Neuropathies               | 
              | Ulnar Neuropathies               | 
              | Ultimobranchial Body               | 
              | Ultracentrifugation               | 
              | Ultradeformable Liposomes use Liposomes               | 
              | Ultradian Cycles use Activity Cycles               | 
              | Ultrafiltration               | 
              | Ultrahigh Frequency Waves use Microwaves               | 
              | Ultramicrotomy use Microtomy               | 
              | Ultrasonic Diagnosis use Ultrasonography               | 
              | Ultrasonic Endoscopy use Endosonography               | 
              | Ultrasonic Imaging use Ultrasonography               | 
              | Ultrasonic Lithotripsy use Lithotripsy               | 
              | Ultrasonic Therapy               | 
              | Ultrasonics               | 
              | Ultrasonography               | 
              | Ultrasonography, Color Doppler use Ultrasonography, Doppler, Color               | 
              | Ultrasonography, Doppler               | 
              | Ultrasonography, Doppler, Color               | 
              | Ultrasonography, Doppler, Duplex               | 
              | Ultrasonography, Doppler, Pulsed               | 
              | Ultrasonography, Doppler, Transcranial               | 
              | Ultrasonography, Duplex Doppler use Ultrasonography, Doppler, Duplex               | 
              | Ultrasonography, Endoscopic use Endosonography               | 
              | Ultrasonography, Fetal use Ultrasonography, Prenatal               | 
              | Ultrasonography, Interventional               | 
              | Ultrasonography, Intravascular use Ultrasonography, Interventional               | 
              | Ultrasonography, Mammary               | 
              | Ultrasonography, Prenatal               | 
              | Ultrasonography, Pulsed Doppler use Ultrasonography, Doppler, Pulsed               | 
              | Ultrasonography, Transcranial Doppler use Ultrasonography, Doppler, Transcranial               | 
              | Ultrasound, High-Intensity Focused, Transrectal               | 
              | Ultrasound, Interventional use Ultrasonography, Interventional               | 
              | Ultraviolet Filters               | 
              | Ultraviolet Microscopy use Microscopy, Ultraviolet               | 
              | Ultraviolet Rays               | 
              | Ultraviolet Spectrophotometry use Spectrophotometry, Ultraviolet               | 
              | Ultraviolet Therapy               | 
              | Ulva               | 
              | Umbelliferae use Apiaceae               | 
              | Umbelliferones               | 
              | Umbellularia               | 
              | Umbilical Arteries               | 
              | Umbilical Cord               | 
              | Umbilical Cord Blood use Fetal Blood               | 
              | Umbilical Cord Blood Stem Cell Transplantation use Cord Blood Stem Cell Transplantation               | 
              | Umbilical Cyst use Urachal Cyst               | 
              | Umbilical Hernia use Hernia, Umbilical               | 
              | Umbilical Veins               | 
              | Umbilicus               | 
              | Umbra use Umbridae               | 
              | Umbrella Filters use Vena Cava Filters               | 
              | Umbrella Tree use Araliaceae               | 
              | Umbridae               | 
              | UMLS use Unified Medical Language System               | 
              | UMP use Uridine Monophosphate               | 
              | UN use United Nations               | 
              | Unaccompanied Child use Unaccompanied Minor               | 
              | Unaccompanied Minor               | 
              | Unaccounted-For Water               | 
              | Unassigned Codon use Codon, Nonsense               | 
              | Uncaria               | 
              | Uncaria procumbens use Harpagophytum               | 
              | Uncaria tomentosa use Cat's Claw               | 
              | Uncertainty               | 
              | Uncinaria stenocephala use Ancylostomatoidea               | 
              | Uncompensated Care               | 
              | Unconscious (Psychology)               | 
              | Unconscious State use Unconsciousness               | 
              | Unconsciousness               | 
              | Uncoupling Agents               | 
              | Undaria               | 
              | Undecylenic Acids               | 
              | Under-Developed Countries use Developing Countries               | 
              | Underachievement               | 
              | Underground Storage use Underground Tanks               | 
              | Underground Streams use Groundwater Flow               | 
              | Underground Tanks               | 
              | Underlying Cause of Death               | 
              | Underpopulation use Population Density               | 
              | Underregistration               | 
              | Understanding use Comprehension               | 
              | Undertaking use Mortuary Practice               | 
              | UNDP use United Nations Development Programme               | 
              | Undulant Fever use Brucellosis               | 
              | Unedited Footage               | 
              | Unemployment               | 
              | UNESCO use United Nations Educational, Scientific and Cultural Organization               | 
              | UNICEF use United Nations               | 
              | Unicism               | 
              | Unified Health System use Single Health System               | 
              | Unified Medical Language System               | 
              | Uniform Flow               | 
              | Unilamellar Liposomes               | 
              | Unilateral Hearing Loss use Hearing Loss, Unilateral               | 
              | Unio               | 
              | Union Lists               | 
              | Union of South Africa use South Africa               | 
              | Union of Soviet Socialist Republics use USSR               | 
              | Unionidae               | 
              | Uniparental Disomy               | 
              | Uniparental Heterodisomy use Uniparental Disomy               | 
              | Uniparental Isodisomy use Uniparental Disomy               | 
              | Unipolar Depression use Depressive Disorder               | 
              | Uniport use Ion Transport               | 
              | Unit Dose Drug Distribution Systems use Medication Systems               | 
              | Unit Operations               | 
              | Unit Process use Unit Operations               | 
              | United Arab Emirates               | 
              | United Arab Republic use Egypt               | 
              | United Kingdom use Great Britain               | 
              | United Nations               | 
              | United Nations Development Program use United Nations Development Programme               | 
              | United Nations Development Programme               | 
              | United Nations Educational, Scientific and Cultural Organization               | 
              | United Nations International Children's Emergency Fund use United Nations               | 
              | United States               | 
              | United States Agency for Health Care Policy and Research use United States Agency for Healthcare Research and Quality               | 
              | United States Agency for Healthcare Research and Quality               | 
              | United States Agency for International Development               | 
              | United States Alcohol, Drug Abuse, and Mental Health Administration use United States Substance Abuse and Mental Health Services Administration               | 
              | United States Centers for Disease Control and Prevention use Centers for Disease Control and Prevention (U.S.)               | 
              | United States Centers for Medicare and Medicaid Services use Centers for Medicare and Medicaid Services (U.S.)               | 
              | United States Department of Agriculture               | 
              | United States Department of Health and Human Services use United States Dept. of Health and Human Services               | 
              | United States Department of Health, Education, and Welfare use United States Dept. of Health and Human Services               | 
              | United States Department of Homeland Security               | 
              | United States Department of Veterans Affairs               | 
              | United States Dept. of Health and Human Services               | 
              | United States Employee Retirement Income Security Act use Employee Retirement Income Security Act               | 
              | United States Environmental Protection Agency               | 
              | United States Federal Trade Commission               | 
              | United States Food and Drug Administration               | 
              | United States Gov't Supported, N.I.H. use Research Support, U.S. Gov't, P.H.S.               | 
              | United States Gov't Supported, Non-P.H.S. use Research Support, U.S. Gov't, Non-P.H.S.               | 
              | United States Gov't Supported, P.H.S. use Research Support, U.S. Gov't, P.H.S.               | 
              | United States Government Agencies               | 
              | United States Health Care Financing Administration use Centers for Medicare and Medicaid Services (U.S.)               | 
              | United States Health Insurance Portability and Accountability Act use Health Insurance Portability and Accountability Act               | 
              | United States Health Resources Administration use United States Health Resources and Services Administration               | 
              | United States Health Resources and Services Administration               | 
              | United States Indian Health Service               | 
              | United States National Academy of Sciences use National Academy of Sciences (U.S.)               | 
              | United States National Aeronautics and Space Administration               | 
              | United States National Center for Health Statistics use National Center for Health Statistics (U.S.)               | 
              | United States National Health Insurance use National Health Insurance, United States               | 
              | United States National Health Planning Information Center use National Health Planning Information Center (U.S.)               | 
              | United States National Institutes of Health use National Institutes of Health (U.S.)               | 
              | United States National Library of Medicine use National Library of Medicine (U.S.)               | 
              | United States Occupational Safety and Health Administration               | 
              | United States Office of Economic Opportunity               | 
              | United States Office of National Drug Control Policy               | 
              | United States Office of Research Integrity               | 
              | United States Office of Technology Assessment               | 
              | United States Office of the Assistant Secretary for Health Office of Research Integrity use United States Office of Research Integrity               | 
              | United States Patient Self-Determination Act use Patient Self-Determination Act               | 
              | United States Public Health Service               | 
              | United States Social Security Administration               | 
              | United States Substance Abuse and Mental Health Services Administration               | 
              | United States Supreme Court use Supreme Court Decisions               | 
              | United States Tax Equity and Fiscal Responsibility Act use Tax Equity and Fiscal Responsibility Act               | 
              | United States Veterans Administration use United States Department of Veterans Affairs               | 
              | United States Visible Human Project use Visible Human Projects               | 
              | Unithiol               | 
              | Units of Hemotherapy use Hemotherapy Service               | 
              | Universal Access To Health Care Services               | 
              | Universal Coverage               | 
              | Universal Precautions               | 
              | Universities               | 
              | University Health Services use Student Health Services               | 
              | University Medical Centers use Academic Medical Centers               | 
              | Unknown Primary Tumors use Neoplasms, Unknown Primary               | 
              | Unleaded Gasoline               | 
              | Unna-Thost Syndrome use Keratoderma, Palmoplantar, Diffuse               | 
              | Unnecessary Procedures               | 
              | Unnecessary Surgery use Unnecessary Procedures               | 
              | Unpublished Works               | 
              | Unsafe Sex               | 
              | Unsaturated Dietary Fats use Dietary Fats, Unsaturated               | 
              | Unsaturated Fats use Fats, Unsaturated               | 
              | Unsaturated Oils use Fats, Unsaturated               | 
              | Unstable DNA Sequence use DNA Sequence, Unstable               | 
              | Untranslated Regions               | 
              | Unux Process Activated Sludges use Pure Oxygen Activated Sludges               | 
              | Unventilated Spaces use Confined Spaces               | 
              | Unverricht-Lundborg Syndrome               | 
              | Up-Regulation               | 
              | Upas antiaris               | 
              | Upas tieute               | 
              | Upflow Anaerobic Reactors               | 
              | Upflow Filters               | 
              | Upflow Filtration               | 
              | Uphill Transport use Biological Transport, Active               | 
              | Upper Aerodigestive Tract Neoplasms use Head and Neck Neoplasms               | 
              | Upper Airway Resistance Sleep Apnea Syndrome use Sleep Apnea, Obstructive               | 
              | Upper Esophageal Sphincter use Esophageal Sphincter, Upper               | 
              | Upper Extremity               | 
              | Upper Extremity Deformities, Congenital               | 
              | Upper Gastrointestinal Tract               | 
              | Upper Limb Deformities, Congenital use Upper Extremity Deformities, Congenital               | 
              | Upper Respiratory Tract Infections use Respiratory Tract Infections               | 
              | Upper Volta use Burkina Faso               | 
              | Upregulation use Up-Regulation               | 
              | Upstream Stimulatory Factors               | 
              | Upwelling               | 
              | Urachal Cyst               | 
              | Urachus               | 
              | Uracil               | 
              | Uracil Arabinofuranoside use Arabinofuranosyluracil               | 
              | Uracil Arabinoside use Arabinofuranosyluracil               | 
              | Uracil Mustard               | 
              | Uracil Nucleotides               | 
              | Uracil Polynucleotides use Poly U               | 
              | Uracil-DNA Glycosidase               | 
              | Uralenic Acid use Glycyrrhetinic Acid               | 
              | Uramustine use Uracil Mustard               | 
              | Uranium               | 
              | Uranium (Homeopathy)               | 
              | Uranium Compounds               | 
              | Uranium Nitricum               | 
              | Uranothorium               | 
              | Uranus               | 
              | Uranyl Nitrate               | 
              | Urate Oxidase               | 
              | Urbach-Wiethe Disease use Lipoid Proteinosis of Urbach and Wiethe               | 
              | Urban Agglomeration use Agglomeration, Urban               | 
              | Urban Agriculture               | 
              | Urban Agriculture Networks               | 
              | Urban Cleaning               | 
              | Urban Cleaning Coverage               | 
              | Urban Cleaning Enterprises               | 
              | Urban Cleaning Equipment               | 
              | Urban Cleaning Service               | 
              | Urban Development use Urban Renewal               | 
              | Urban Fires               | 
              | Urban Health               | 
              | Urban Health Services               | 
              | Urban Horticulture use Urban Agriculture               | 
              | Urban Hospitals use Hospitals, Urban               | 
              | Urban Planning use City Planning               | 
              | Urban Population               | 
              | Urban Population Health use Urban Health               | 
              | Urban Renewal               | 
              | Urban Sanitation               | 
              | Urban Settlements               | 
              | Urban Villages use Urban Settlements               | 
              | Urban Zones               | 
              | Urban-Rural Migration use Rural-Urban Migration               | 
              | Urbanization               | 
              | Urea               | 
              | Urea Nitrica               | 
              | Urea Pura               | 
              | Ureaplasma               | 
              | Ureaplasma Infections               | 
              | Ureaplasma parvum use Ureaplasma               | 
              | Ureaplasma urealyticum               | 
              | Urease               | 
              | Urecholine use Bethanechol Compounds               | 
              | Uremia               | 
              | Ureohydrolases               | 
              | Ureter               | 
              | Ureteral Calculi               | 
              | Ureteral Cancer use Ureteral Neoplasms               | 
              | Ureteral Diseases               | 
              | Ureteral Neoplasms               | 
              | Ureteral Obstruction               | 
              | Ureterocele               | 
              | Ureterolithiasis               | 
              | Ureteroscopes               | 
              | Ureteroscopic Surgical Procedures use Ureteroscopy               | 
              | Ureteroscopy               | 
              | Ureterostomy               | 
              | Urethane               | 
              | Urethra               | 
              | Urethral Cancer use Urethral Neoplasms               | 
              | Urethral Diseases               | 
              | Urethral Neoplasms               | 
              | Urethral Obstruction               | 
              | Urethral Stenosis use Urethral Stricture               | 
              | Urethral Stricture               | 
              | Urethritis               | 
              | Urgencies use Emergencies               | 
              | Urginea               | 
              | Urginea scilla use Squilla maritima               | 
              | Uric Acid               | 
              | Uricase use Urate Oxidase               | 
              | Uricosuric Agents               | 
              | Uricum Acidum               | 
              | Uridine               | 
              | Uridine Diphosphate               | 
              | Uridine Diphosphate Galactose               | 
              | Uridine Diphosphate Glucose               | 
              | Uridine Diphosphate Glucose Dehydrogenase               | 
              | Uridine Diphosphate Glucose Epimerase use UDPglucose 4-Epimerase               | 
              | Uridine Diphosphate Glucuronic Acid               | 
              | Uridine Diphosphate N-Acetylgalactosamine               | 
              | Uridine Diphosphate N-Acetylglucosamine               | 
              | Uridine Diphosphate N-Acetylmuramic Acid               | 
              | Uridine Diphosphate Sugars               | 
              | Uridine Diphosphate Xylose               | 
              | Uridine Diphospho-N-Acetylglucosamine use Uridine Diphosphate N-Acetylglucosamine               | 
              | Uridine Diphosphogalactose use Uridine Diphosphate Galactose               | 
              | Uridine Diphosphoglucose use Uridine Diphosphate Glucose               | 
              | Uridine Diphosphoglucuronic Acid use Uridine Diphosphate Glucuronic Acid               | 
              | Uridine Kinase               | 
              | Uridine Monophosphate               | 
              | Uridine Phosphates use Uracil Nucleotides               | 
              | Uridine Phosphorylase               | 
              | Uridine Pyrophosphoacetylglucosamine use Uridine Diphosphate N-Acetylglucosamine               | 
              | Uridine Pyrophosphogalactose use Uridine Diphosphate Galactose               | 
              | Uridine Triphosphate               | 
              | Uridyl Transferase use UDPglucose-Hexose-1-Phosphate Uridylyltransferase               | 
              | Uridylate 5'-Nucleotidase use 5'-Nucleotidase               | 
              | Uridylic Acid use Uridine Monophosphate               | 
              | Urinals use Sanitary Devices               | 
              | Urinalysis               | 
              | Urinary Bladder               | 
              | Urinary Bladder Calculi               | 
              | Urinary Bladder Diseases               | 
              | Urinary Bladder Fistula               | 
              | Urinary Bladder Neck Obstruction               | 
              | Urinary Bladder Neoplasms               | 
              | Urinary Bladder Prolapse use Cystocele               | 
              | Urinary Bladder Stones use Urinary Bladder Calculi               | 
              | Urinary Bladder, Neurogenic               | 
              | Urinary Bladder, Overactive               | 
              | Urinary Calculi               | 
              | Urinary Catheterization               | 
              | Urinary Diversion               | 
              | Urinary Fistula               | 
              | Urinary Incontinence               | 
              | Urinary Incontinence, Stress               | 
              | Urinary Incontinence, Urge               | 
              | Urinary Kallikrein use Tissue Kallikreins               | 
              | Urinary Plasminogen Activator use Urokinase-Type Plasminogen Activator               | 
              | Urinary Reservoirs, Continent               | 
              | Urinary Retention               | 
              | Urinary Sphincter, Artificial               | 
              | Urinary Stones use Urinary Calculi               | 
              | Urinary Tract               | 
              | Urinary Tract Cancer use Urologic Neoplasms               | 
              | Urinary Tract Diseases use Urologic Diseases               | 
              | Urinary Tract Infections               | 
              | Urinary Tract Physiological Phenomena               | 
              | Urinary Tract Physiological Processes               | 
              | Urinary Tract Physiology use Urinary Tract Physiological Phenomena               | 
              | Urination               | 
              | Urination Disorders               | 
              | Urine               | 
              | Urine Concentrating Ability use Kidney Concentrating Ability               | 
              | Urinoma               | 
              | Urobilin               | 
              | Urobilinogen               | 
              | Urocanase use Urocanate Hydratase               | 
              | Urocanate Hydratase               | 
              | Urocanic Acid               | 
              | Urochordata               | 
              | Urocortin use Urocortins               | 
              | Urocortins               | 
              | Urocyon use Foxes               | 
              | Urodela               | 
              | Urodynamics               | 
              | Urofollitropin               | 
              | Urogastrone use Epidermal Growth Factor               | 
              | Urogastrone Receptor use Receptor, Epidermal Growth Factor               | 
              | Urogenital Abnormalities               | 
              | Urogenital Cancer use Urogenital Neoplasms               | 
              | Urogenital Neoplasms               | 
              | Urogenital Surgical Procedures               | 
              | Urogenital System               | 
              | Urography               | 
              | Urokinase use Urokinase-Type Plasminogen Activator               | 
              | Urokinase-Type Plasminogen Activator               | 
              | Urolithiasis               | 
              | Urologic Cancer use Urologic Neoplasms               | 
              | Urologic Diseases               | 
              | Urologic Neoplasms               | 
              | Urologic Surgical Procedures               | 
              | Urologic Surgical Procedures, Male               | 
              | Urological Manifestations               | 
              | Urology               | 
              | Urology Department, Hospital               | 
              | Uronic Acids               | 
              | Uropepsinogen use Pepsinogen A               | 
              | Uroporphyrinogen Carboxy-Lyase use Uroporphyrinogen Decarboxylase               | 
              | Uroporphyrinogen Decarboxylase               | 
              | Uroporphyrinogen I Synthase use Hydroxymethylbilane Synthase               | 
              | Uroporphyrinogen III Cosynthetase use Uroporphyrinogen III Synthetase               | 
              | Uroporphyrinogen III Synthetase               | 
              | Uroporphyrinogen Isomerase use Uroporphyrinogen III Synthetase               | 
              | Uroporphyrinogen-III Synthase use Uroporphyrinogen III Synthetase               | 
              | Uroporphyrinogens               | 
              | Uroporphyrins               | 
              | Urotensins               | 
              | Urothelium               | 
              | Ursidae               | 
              | Ursodeoxycholic Acid               | 
              | Ursus use Ursidae               | 
              | Urtica crenulata               | 
              | Urtica dioica               | 
              | Urtica gigas               | 
              | Urtica urens               | 
              | Urticaceae               | 
              | Urticaria               | 
              | Urticaria Pigmentosa               | 
              | Urticaria, Giant use Angioedema               | 
              | Uruguay               | 
              | Urundi use Burundi               | 
              | US Agency for International Development use United States Agency for International Development               | 
              | US AID use United States Agency for International Development               | 
              | USAID use United States Agency for International Development               | 
              | USDA use United States Department of Agriculture               | 
              | Use of Radiation in Medicine and Investigation               | 
              | Use of Radiation on Energy               | 
              | Use of Radiation on Industry               | 
              | Use of Scientific Information for Health Decision Making               | 
              | Used Oils use Lubricant Oils               | 
              | Used Rubber Tires use Tires               | 
              | Used Tires use Tires               | 
              | User Embracement               | 
              | User-Computer Interface               | 
              | Uses of Epidemiology               | 
              | Uses of Radiation               | 
              | USFDA use United States Food and Drug Administration               | 
              | USFTC use United States Federal Trade Commission               | 
              | Usher Syndromes               | 
              | Usnea               | 
              | Usnea barbata use Usnea               | 
              | Usnea Barbata (Homeopathy)               | 
              | USPHS use United States Public Health Service               | 
              | USSR               | 
              | Ustilaginales               | 
              | Ustilago               | 
              | Ustilago maydis               | 
              | Utah               | 
              | Uterine Appendages use Adnexa Uteri               | 
              | Uterine Artery Embolization               | 
              | Uterine Cancer use Uterine Neoplasms               | 
              | Uterine Cervical Diseases               | 
              | Uterine Cervical Dysplasia               | 
              | Uterine Cervical Erosion               | 
              | Uterine Cervical Incompetence               | 
              | Uterine Cervical Neoplasms               | 
              | Uterine Cervicitis               | 
              | Uterine Contraction               | 
              | Uterine Diseases               | 
              | Uterine Endoscopy use Hysteroscopy               | 
              | Uterine Hemorrhage               | 
              | Uterine Inertia               | 
              | Uterine Inversion               | 
              | Uterine Monitoring               | 
              | Uterine Muscle use Myometrium               | 
              | Uterine Neoplasms               | 
              | Uterine Perforation               | 
              | Uterine Prolapse               | 
              | Uterine Rupture               | 
              | Uterine Stimulants use Oxytocics               | 
              | Uteroglobin               | 
              | Uteroplacental Circulation use Placental Circulation               | 
              | Uteroscopes use Hysteroscopes               | 
              | Uteroverdine use Biliverdine               | 
              | Uterus               | 
              | Utility Failure use Interruption of Services Supply               | 
              | Utilization and Quality Control Peer Review Organizations use Professional Review Organizations               | 
              | Utilization Review               | 
              | Utilization Review, Drug use Drug Utilization Review               | 
              | Utopias               | 
              | UTP use Uridine Triphosphate               | 
              | UTP-Glucose-1-Phosphate Uridylyltransferase               | 
              | UTP-Hexose-1-Phosphate Uridylyltransferase               | 
              | Utricle use Saccule and Utricle               | 
              | Utrophin               | 
              | UTRs use Untranslated Regions               | 
              | Uukuniemi Group Viruses use Uukuniemi virus               | 
              | Uukuniemi virus               | 
              | Uva ursi (Homeopathy)               | 
              | Uva-ursi use Arctostaphylos               | 
              | Uvaria               | 
              | Uvaria triloba               | 
              | Uvea               | 
              | Uveal Diseases               | 
              | Uveal Neoplasms               | 
              | Uveitis               | 
              | Uveitis, Anterior               | 
              | Uveitis, Intermediate               | 
              | Uveitis, Posterior               | 
              | Uveitis, Suppurative               | 
              | Uveitis, Sympathetic use Ophthalmia, Sympathetic               | 
              | Uveomeningoencephalitic Syndrome               | 
              | Uveomeningoencephalitis use Uveomeningoencephalitic Syndrome               | 
              | Uveoparotid Fever               | 
              | Uveoparotitis use Uveoparotid Fever               | 
              | Uvomorulin use Cadherins               | 
              | Uvula               | 
              | Uzara               | 
              | Uzbek S.S.R. use Uzbekistan               | 
              | Uzbekistan               |