Methylene Blue: A compound consisting of dark green crystals or crystalline powder, having a bronze-like luster. Solutions in water or alcohol have a deep blue color. Methylene blue is used as a bacteriologic stain and as an indicator. It inhibits GUANYLATE CYCLASE, and has been used to treat cyanide poisoning and to lower levels of METHEMOGLOBIN.Methylene Chloride: A chlorinated hydrocarbon that has been used as an inhalation anesthetic and acts as a narcotic in high concentrations. Its primary use is as a solvent in manufacturing and food technology.Methemoglobinemia: The presence of methemoglobin in the blood, resulting in cyanosis. A small amount of methemoglobin is present in the blood normally, but injury or toxic agents convert a larger proportion of hemoglobin into methemoglobin, which does not function reversibly as an oxygen carrier. Methemoglobinemia may be due to a defect in the enzyme NADH methemoglobin reductase (an autosomal recessive trait) or to an abnormality in hemoglobin M (an autosomal dominant trait). (Dorland, 27th ed)Coloring Agents: Chemicals and substances that impart color including soluble dyes and insoluble pigments. They are used in INKS; PAINTS; and as INDICATORS AND REAGENTS.Tolonium Chloride: A phenothiazine that has been used as a hemostatic, a biological stain, and a dye for wool and silk. Tolonium chloride has also been used as a diagnostic aid for oral and gastric neoplasms and in the identification of the parathyroid gland in thyroid surgery.Photosensitizing Agents: Drugs that are pharmacologically inactive but when exposed to ultraviolet radiation or sunlight are converted to their active metabolite to produce a beneficial reaction affecting the diseased tissue. These compounds can be administered topically or systemically and have been used therapeutically to treat psoriasis and various types of neoplasms.Cyclic GMP: Guanosine cyclic 3',5'-(hydrogen phosphate). A guanine nucleotide containing one phosphate group which is esterified to the sugar moiety in both the 3'- and 5'-positions. It is a cellular regulatory agent and has been described as a second messenger. Its levels increase in response to a variety of hormones, including acetylcholine, insulin, and oxytocin and it has been found to activate specific protein kinases. (From Merck Index, 11th ed)Guanylate Cyclase: An enzyme that catalyzes the conversion of GTP to 3',5'-cyclic GMP and pyrophosphate. It also acts on ITP and dGTP. (From Enzyme Nomenclature, 1992) EC 4.6.1.2.Nitric Oxide: A free radical gas produced endogenously by a variety of mammalian cells, synthesized from ARGININE by NITRIC OXIDE SYNTHASE. Nitric oxide is one of the ENDOTHELIUM-DEPENDENT RELAXING FACTORS released by the vascular endothelium and mediates VASODILATION. It also inhibits platelet aggregation, induces disaggregation of aggregated platelets, and inhibits platelet adhesion to the vascular endothelium. Nitric oxide activates cytosolic GUANYLATE CYCLASE and thus elevates intracellular levels of CYCLIC GMP.Phenothiazines: Compounds containing dibenzo-1,4-thiazine. Some of them are neuroactive.Muscle Relaxation: That phase of a muscle twitch during which a muscle returns to a resting position.Indigo Carmine: Indolesulfonic acid used as a dye in renal function testing for the detection of nitrates and chlorates, and in the testing of milk.Photochemotherapy: Therapy using oral or topical photosensitizing agents with subsequent exposure to light.PurinonesNitroprusside: A powerful vasodilator used in emergencies to lower blood pressure or to improve cardiac function. It is also an indicator for free sulfhydryl groups in proteins.Antidotes: Agents counteracting or neutralizing the action of POISONS.Arginine: An essential amino acid that is physiologically active in the L-form.Trypan Blue: A diazo-naphthalene sulfonate that is widely used as a stain.Vasoplegia: Condition of low SYSTEMIC VASCULAR RESISTANCE that develops secondary to other conditions such as ANAPHYLAXIS; SEPSIS; SURGICAL SHOCK; and SEPTIC SHOCK. Vasoplegia that develops during or post surgery (e.g., CARDIOPULMONARY BYPASS) is called postoperative vasoplegic syndrome or vasoplegic syndrome.Dental Leakage: The seepage of fluids, debris, and micro-organisms between the walls of a prepared dental cavity and the restoration.Imidazolines: Compounds based on reduced IMIDAZOLES containing a single double bond.Evans Blue: An azo dye used in blood volume and cardiac output measurement by the dye dilution method. It is very soluble, strongly bound to plasma albumin, and disappears very slowly.Singlet Oxygen: An excited state of molecular oxygen generated photochemically or chemically. Singlet oxygen reacts with a variety of biological molecules such as NUCLEIC ACIDS; PROTEINS; and LIPIDS; causing oxidative damages.Agar: A complex sulfated polymer of galactose units, extracted from Gelidium cartilagineum, Gracilaria confervoides, and related red algae. It is used as a gel in the preparation of solid culture media for microorganisms, as a bulk laxative, in making emulsions, and as a supporting medium for immunodiffusion and immunoelectrophoresis.Dysuria: Painful URINATION. It is often associated with infections of the lower URINARY TRACT.Nitroarginine: An inhibitor of nitric oxide synthetase which has been shown to prevent glutamate toxicity. Nitroarginine has been experimentally tested for its ability to prevent ammonia toxicity and ammonia-induced alterations in brain energy and ammonia metabolites. (Neurochem Res 1995:200(4):451-6)Enzyme Inhibitors: Compounds or agents that combine with an enzyme in such a manner as to prevent the normal substrate-enzyme combination and the catalytic reaction.Dictionaries, ChemicalAgrochemicals: Chemicals used in agriculture. These include pesticides, fumigants, fertilizers, plant hormones, steroids, antibiotics, mycotoxins, etc.Dictionaries, MedicalDictionaries as Topic: Lists of words, usually in alphabetical order, giving information about form, pronunciation, etymology, grammar, and meaning.Biopharmaceutics: The study of the physical and chemical properties of a drug and its dosage form as related to the onset, duration, and intensity of its action.Pharmaceutical Preparations: Drugs intended for human or veterinary use, presented in their finished dosage form. Included here are materials used in the preparation and/or formulation of the finished dosage form.Fruit: The fleshy or dry ripened ovary of a plant, enclosing the seed or seeds.Tea: The infusion of leaves of CAMELLIA SINENSIS (formerly Thea sinensis) as a beverage, the familiar Asian tea, which contains CATECHIN (especially epigallocatechin gallate) and CAFFEINE.Malaria: A protozoan disease caused in humans by four species of the PLASMODIUM genus: PLASMODIUM FALCIPARUM; PLASMODIUM VIVAX; PLASMODIUM OVALE; and PLASMODIUM MALARIAE; and transmitted by the bite of an infected female mosquito of the genus ANOPHELES. Malaria is endemic in parts of Asia, Africa, Central and South America, Oceania, and certain Caribbean islands. It is characterized by extreme exhaustion associated with paroxysms of high FEVER; SWEATING; shaking CHILLS; and ANEMIA. Malaria in ANIMALS is caused by other species of plasmodia.Diet: Regular course of eating and drinking adopted by a person or animal.Antioxidants: Naturally occurring or synthetic substances that inhibit or retard the oxidation of a substance to which it is added. They counteract the harmful and damaging effects of oxidation in animal tissues.Thyroidectomy: Surgical removal of the thyroid gland. (Dorland, 28th ed)Thyroid Gland: A highly vascularized endocrine gland consisting of two lobes joined by a thin band of tissue with one lobe on each side of the TRACHEA. It secretes THYROID HORMONES from the follicular cells and CALCITONIN from the parafollicular cells thereby regulating METABOLISM and CALCIUM level in blood, respectively.Intraoperative Care: Patient care procedures performed during the operation that are ancillary to the actual surgery. It includes monitoring, fluid therapy, medication, transfusion, anesthesia, radiography, and laboratory tests.Thyroid Neoplasms: Tumors or cancer of the THYROID GLAND.Intraoperative Period: The period during a surgical operation.Monitoring, Intraoperative: The constant checking on the state or condition of a patient during the course of a surgical operation (e.g., checking of vital signs).Millettia: A plant genus of the family FABACEAE. Members contain ISOFLAVONES, some of which show molluscicidal and schistosomicidal activity. Some species of Pongamia have been reclassified to this genus and some to DERRIS.Rhodamines: A family of 3,6-di(substituted-amino)-9-benzoate derivatives of xanthene that are used as dyes and as indicators for various metals; also used as fluorescent tracers in histochemistry.Pongamia: A plant genus of the family FABACEAE. Members contain karanjin. Some species of this genus have been reclassified to other genera of FABACEAE including Callerya, DERRIS and MILLETTIA.Adsorption: The adhesion of gases, liquids, or dissolved solids onto a surface. It includes adsorptive phenomena of bacteria and viruses onto surfaces as well. ABSORPTION into the substance may follow but not necessarily.Charcoal: An amorphous form of carbon prepared from the incomplete combustion of animal or vegetable matter, e.g., wood. The activated form of charcoal is used in the treatment of poisoning. (Grant & Hackh's Chemical Dictionary, 5th ed)Rhodamine 123: A fluorescent probe with low toxicity which is a potent substrate for P-glycoprotein and the bacterial multidrug efflux transporter. It is used to assess mitochondrial bioenergetics in living cells and to measure the efflux activity of P-glycoprotein in both normal and malignant cells. (Leukemia 1997;11(7):1124-30)Methenamine: An anti-infective agent most commonly used in the treatment of urinary tract infections. Its anti-infective action derives from the slow release of formaldehyde by hydrolysis at acidic pH. (From Martindale, The Extra Pharmacopoeia, 30th ed, p173)Hyoscyamine: The 3(S)-endo isomer of atropine.Atropa belladonna: A plant species of the genus ATROPA, family SOLANACEAE that contains ATROPINE; SCOPOLAMINE; BELLADONNA ALKALOIDS and other SOLANACEOUS ALKALOIDS. Some species in this genus are called deadly nightshade which is also a common name for SOLANUM.Spasm: An involuntary contraction of a muscle or group of muscles. Spasms may involve SKELETAL MUSCLE or SMOOTH MUSCLE.Phenazopyridine: A local anesthetic that has been used in urinary tract disorders. Its use is limited by problems with toxicity (primarily blood disorders) and potential carcinogenicity.Datura stramonium: A plant species of the genus DATURA, family SOLANACEAE, that contains TROPANES and other SOLANACEOUS ALKALOIDS.