CHAPTER 21 INDEXING PRINCIPLES FOR CATEGORY A (ANATOMICAL TERMS) 21.1 Category A is a collection of MeSH terms for organs, regions, tissues and cells in the human and animal body. They represent the concepts most frequently met in anatomy literature. For organs, tissues and cells not in MeSH, subheadings are available as a means of indexing and retrieving specific anatomical concepts. 21.2 The following subheadings are permitted with Category A terms /abnormalities /microbiology /anatomy & histology /parasitology /blood supply /pathology /chemistry /physiology /classification (A 11 only) /physiopathology /cytology /radiation effects /drug effects /radiography /embryology /radionuclide imaging /enzymology /secretion /genetics (subcellular elements only) /growth & development /surgery /immunology /transplantation /injuries /ultrasonography /innervation /ultrastructure /metabolism /virology 21.3 Not every subheading listed in 21.2 is permitted with every Category A term. The subheadings permitted with a particular term can be found in the AQ field for that term. 21.4 Index a blood vessel for which there is no MeSH heading under the name of the organ with the subheading /blood supply (IM) and coordinate with the type of vessel (NIM). Pancreatic artery. PANCREAS /* blood supply ARTERIES 21.4.1 Do not index a vessel which feeds into or branches from a larger vessel under the name of the larger vessel even though that term is in MeSH. Gastric artery. STOMACH / *blood supply ARTERIES (not under HEPATIC ARTERY or CELIAC ARTERY from which the right and left gastric arteries originate respectively). 21.4.2 /blood supply refers not only to the vessels themselves supplying an organ but also to the circulation through those vessels. If an article discusses circulation or the circulatory process, index also under REGIONAL BLOOD FLOW (NIM). Do not index under BLOOD CIRCULATION for this heading is reserved for general, i.e., systemic circulation. Blood circulation of the forearm. FOREARM /* blood supply REGIONAL BLOOD FLOW / physiol 21.5 MICROCIRCULATION (A7, G9) refers to either the anatomy or the physiology of microcirculation by virtue of its category assignments. When used with a specific organ with /blood supply (IM), MICROCIRCULATION is NIM. Microcirculation of the skin. SKIN / *blood supply MICROCIRCULATION / physiol 21.6 A few pre-coordinated circulation headings exist in Category G9, for example, LIVER CIRCULATION, RENAL CIRCULATION, and PULMONARY CIRCULATION. These are physiological concepts and therefore do not replace LIVER / blood supply, KIDNEY / blood supply or LUNG/ blood supply for anatomical aspects of blood vessels to these organs. SPLANCHNIC CIRCULATION is the circulation of blood through vessels supplying the abdominal viscera. The effect of ethanol on splanchnic blood flow. ETHANOL /* pharmacol SPLANCHNIC CIRCULATION /* drug eff The effect of ethanol on capillaries in the liver. ETHANOL /* pharmacol CAPILLARIES / drug eff LIVER /* blood supply / drug eff (not LIVER CIRCULATION / drug eff) 21.7 Index a nerve for which there is no MeSH term under the name of the organ with the subheading /innervation. When indicated, index also under a more specific nervous system heading such as SYMPATHETIC NERVOUS SYSTEM. Do not, however, index under NERVE TISSUE. Do not index a nerve which feeds into or branches from a larger nerve under the larger nerve even though that term is in MeSH. Gastric nerve. STOMACH / * innerv Autonomic innervation of the stomach. STOMACH / * innerv *AUTONOMIC NERVOUS SYSTEM Vagal innervation of the stomach. STOMACH / * innerv *VAGUS NERVE Saphenous nerve. LEG /* innerv (not also PERIPHERAL NERVES) 21.8 Index muscles not in MeSH under the name of the organ (IM) and MUSCLE, SKELETAL (IM), MUSCLE, SMOOTH (IM) or MUSCLES (IM). Thigh muscle. *THIGH *MUSCLE, SKELETAL 21.9 Frequently articles are written on muscle as tissue rather than as an organ of movement. In such cases, index under the muscle term (IM) with the site, being of secondary importance, as NIM. Often in relation to third-tier indexing (20.11), the site might not be picked up at all. Glucose metabolism in smooth muscle. (Rat ileum is used.) GLUCOSE / * metab MUSCLE, SMOOTH / * metab ILEUM / metab RATS (check tag) ANIMAL (check tag) 21.10 Index MEMBRANES and its indentions in Category A10 as IM for general articles; index them as NIM when a specific organ is IM. This is true also for EPITHELIUM and its indentions. 21.11 Index cells of an organ under the name of the organ with the subheading /cytology (IM). Index the microanatomic structure of organs or cells under the organ or cell with the subheading /ultrastructure (IM). Determination of the size of renal tubular cells. KIDNEY TUBULES /* cytol CELL SIZE Fine structure of the middle ear epithelium of the chicken. EAR, MIDDLE /* ultrastruct EPITHELIUM / ultrastruct CHICKENS ANIMAL (check tag) 21.11.1 If subcellular elements of an organ or cell are discussed, index the subcellular element IM or NIM depending on the emphasis of the article. Comparison of nuclear DNA synthesis in hepatocytes and muscle cells. DNA / *biosyn CELL NUCLEUS / metab LIVER / *metab /cytol MUSCLES / *metab / cytol COMPARATIVE STUDY (check tag) A study of protein glycosylation in the Golgi apparatus using fibroblasts. GOLGI APPARATUS / *metab PROTEINS / *metab GLYCOSYLATION FIBROBLASTS /metab Lysosome structure in retinal pigment epithelium. LYSOSOMES /* ultrastruct PIGMENT EPITHELIUM of EYE /* ultrastruct 21.12 Index the function of an organ under the name of the organ with the subheading /physiology. The physiology of the stomach in digestion. STOMACH / *physiol DIGESTION / *physiol Brain function during thinking. BRAIN / * physiol THINKING / * physiol 21.13 Index the effect of a drug on an organ under the organ with the subheading /drug effects (IM) and the drug or chemical with the subheading /pharmacology. The effect of bronchodilators on the lung. BRONCHODILATOR AGENTS / * pharmacol LUNG /* drug eff 21.13.1 Frequently the effect of a drug is on some specific aspect of an organ such as its metabolism, function or structure. In these cases, index the organ with both /drug effects and a subheading to cover the other aspect. Tend to make /drug effects IM particularly in pharmacology journals. If in doubt, if the drug is NIM, then the organ /drug effects will probably be NIM with the other subheading on the organ IM. The effect of LSD on histone acetylation in the brain. LSD / * pharmacol BRAIN / * drug eff / metab HISTONES / * metab ACETYLATION / drug eff Ultrastructural study of rat hepatocytes in the presence of cortisone. CORTISONE / * pharmacol LIVER / *drug eff /ultrastruct RATS (check tag) ANIMAL (check tag) Effect of alpha-ketoglutarate on glutamate dehydrogenase activity in rat liver mitochondria. ALPHA-KETOGLUTARATE /* pharmacol MITOCHONDRIA, LIVER / * enzymol / drug eff GLUTAMATE DEHYDROGENASE /* metab RATS (check tag) ANIMAL (check tag) Although /drug effects is allowed with enzymes, it is rarely used except for the effect of a drug on the chemical structure of an enzyme. 21.14 Index the effect of various radiations on an organ under the name of the organ with the subheading /radiation effects (IM) and under the specific radiation (IM). The effect of ultraviolet rays on the skin. SKIN /*rad eff *ULTRAVIOLET RAYS The effect of microwaves on the cell membrane. CELL MEMBRANE / *rad eff *MICROWAVES 21.15 When the radiation affects a specific aspect of an organ or tissue, index under both the organ with the subheading /radiation effects and the other aspect of the organ (metabolism, structure, etc.) The /radiation effects combination will probably be IM, the other combination NIM. The effect of gamma rays on DNA synthesis in muscle mitochondria. MITOCHONDRIA, MUSCLE / * rad eff / metab *GAMMA RAYS DNA, MITOCHONDRIAL/ *rad eff / biosyn 21.16 Do not coordinate the Category A term with RADIATION, IONIZING or RADIATION, NON-IONIZING unless the article is very general and the nature of the radiation seems to be the point of the study. See sections 28.11-13 for further discussion of radiation. The effect of irradiation of the liver on subsequent blood coagulation. (the author states that ionizing radiation was used) LIVER /*rad eff BLOOD COAGULATION / *rad eff (do not index RADIATION, IONIZING) 21.17 Index articles on the metabolism of a substance by an organ under the name of the organ with the subheading /metabolism IM and the name of the substance with the subheading /metabolism IM. See 19.8.43 and 19.10.4 for a discussion of the coverage of the concept "metabolism". Glucose metabolism in the kidney. KIDNEY /* metab GLUCOSE /* metab Turnover of alanine in brain neuroglia. ALANINE /* metab BRAIN /* metab / cytol NEUROGLIA/* metab 21.18 Index the chemistry or chemical composition of an organ or tissue under the name of the organ with the subheading /chemistry. Do not add specific chemistry terms as coordinates such as NEUROCHEMISTRY or BIOCHEMISTRY. The chemical composition of the liver. LIVER /*chem The chemistry of regenerating nerve tissue. NERVE TISSUE / * chem / physiol *NERVE REGENERATION (do not index also under NEUROCHEMISTRY) 21.18.1 Brain chemistry is an exception to this and is indexed with the precoordinated term BRAIN CHEMISTRY. 21.18.2 The presence of a substance in an organ is related to the above concept. Index the substance with the subheading /analysis (IM) and coordinate with the organ with the subheading /chemistry (IM). Collagen content of muscle. MUSCLES /*chem COLLAGEN /*anal Phospholipid content of the brain. PHOSPHOLIPIDS /*anal *BRAIN CHEMISTRY 21.19 Index the secretion of a substance by an organ under the name of the organ with the subheading /secretion (IM). If the substance is also discussed, index it with the same subheading. Do not seek to add routinely the name of every organ naturally secreting substances by checking physiology texts to determine the organ heading. Index on the basis of the article. Index both the organ and the substance it secretes only if the author discusses both. Circadian rhythm in pituitary secretion. *CIRCADIAN RHYTHM PITUITARY GLAND /* secret Circadian rhythm in the pituitary secretion of prolactin. PITUITARY GLAND/*secret PROLACTIN /*secret *CIRCADIAN RHYTHM Circadian rhythm in prolactin secretion. PROLACTIN /*secret *CIRCADIAN RHYTHM 21.20 Index a disease of an organ or tissue under the pre-coordinated organ-disease term applicable from Category C (diseases) if it is an exact equivalent of the desired concept. Mouth neoplasms. *MOUTH NEOPLASMS (not MOUTH + NEOPLASMS) Shoulder fractures. *SHOULDER FRACTURES (not SHOULDER and FRACTURES) Gastritis. *GASTRITIS (not STOMACH and INFLAMMATION) 21.21 If a pre-coordinated organ disease concept is not in MeSH, index the organ IM and add the most specific Category C disease term NIM. See section 23.11. Diseases of the ciliary body. *CILIARY BODY UVEAL DISEASES (Ciliary Body is indented in Category A under UVEA and there is a term UVEAL DISEASES in Category Cll). 21.21.1 If the intended coordinate is more specific than the pre-coordinated organ/disease term, index under the organ (IM) and the pre-coordinated disease (IM). Ciliary body neoplasms. *CILIARY BODY *UVEAL NEOPLASMS 21.21.2 The above instructions represent general principles of indexing organ/diseases not in MeSH. The matter of IM or NIM sometimes changes in certain circumstances. Always check the Annotated MeSH for guidelines on IM or NIM with specific headings. See also section 23 for detailed instructions on indexing diseases. 21.22 The term "pathology" is taken to mean the structural or morphological changes in organs, tissues and cells in disease states. It is not meant by MeSH as a synonym for "disease" nor as a substitute for a pre- coordinated organ/disease heading lacking in MeSH. 21.22.1 Examine the term "pathology" as used by an author. If the author means by "pathology" what INDEX MEDICUS means - a description of non-normal organs, tissues and cells or a description of their structure in disease states then use the subheading /pathology with the organ. If, on the other hand, the author is using an expression such as "lung pathology" to mean lung disease, the correct heading is LUNG DISEASES, not LUNG /pathology. 21.23 Index the pathology of an organ under the name of the organ with the subheading /pathology (IM). Pathology of the liver. LIVER /* pathol 21.24 Index the pathology of an organ in a disease of that organ under the name of the organ with the subheading /pathology (IM) and the name of the disease with the subheading /pathology (IM). The structure of the liver in hepatitis. LIVER /* pathol HEPATITIS /* pathol The hepatocyte in liver diseases. LIVER /* pathol LIVER DISEASES /* pathol 21.25 Index the pathology of an organ in a disease unrelated to that organ under the name of the organ with the subheading /pathology (IM) and the name of the disease with the subheading /pathology (IM). Kidney pathology in stomach diseases. KIDNEY /* pathol STOMACH DISEASES /* pathol 21.26 Use the subheading /pathology to cover the anatomy, histology, or cytology of an organ in a disease state. Use the subheading /ultrastructure to cover pathological ultrastructure or ultrastructure in a disease state. Stomach tissue in hepatitis. STOMACH /* pathol HEPATITIS / * pathol Liver and kidney cells in encephalitis. LIVER /* pathol KIDNEY / * pathol ENCEPHALITIS /* pathol The ultrastructure of the kidney in kidney disease. KIDNEY /*ultrastruct KIDNEY DISEASES /* pathol (/ultrastructure is permitted only with diseases in Category C4 - Neoplasms) 21.27 The physiopathology of an organ must be distinguished from its physiology and pathology. Physiology is the normal function of an organ; pathology is the structure of an organ in a disease state or non-normal structure of an organ. Physiopathology is the disordered function of an organ in a disease state. 21.28 Index the physiopathology of an organ under the name of the organ with the subheading /physiopathology (IM) and the name of the disease with the subheading /physiopathology (IM). The physiopathology of the pancreas. PANCREAS / * physiopathol The function of the pancreas in pancreatitis. PANCREAS /* physiopathol PANCREATITIS / * physiopathol Abnormal function of the liver in colitis. LIVER/* physiopathol COLITIS /* physiopathol 21.29 As with the term "pathology" (21.22.1), examine the term "physiopathology" used by an author. If the author means by "physiopathology" what INDEX MEDICUS means - the disordered function of an organ in a disease - then use the subheading /physiopathology with the organ. If, on the other hand, the author is using an expression such as "lung physiopathology" to mean lung diseases, then use the term LUNG DISEASES, not LUNG /physiopathology. Again, like /pathology (21.22), /physiopathology is not meant to be used as a substitute for a pre-coordinated organ/diseases heading not in MeSH. 21.30 Index wounds or injuries of an organ under the name of the organ with the subheading /injuries (IM). The word "trauma" or "traumatic" appears in titles and means our term "injuries". In foreign titles do not translate "traumatism" in various cognate forms as "trauma" or "traumatism": translate as "injury". Stomach wounds. STOMACH /* inj 21.31 Since wounds and injuries are so frequent in medicine, MeSH has supplied many specific types of wounds and injuries and pre-coordinated injury concepts. Always prefer an applicable pre-coordinate to the organ with the subheading /injuries. Head wounds. *HEAD INJURIES (not HEAD /* inj) 21.32 Index specific types of injuries under the name of the organ with the subheading /injuries (IM) and the specific type of wound or injury from Category C21. See Section 23.23+. Stab wounds of the uterus. UTERUS /* inj *WOUNDS, STAB Penetrating injuries of the neck. NECK /* inj *WOUNDS, PENETRATING Chemical burns of the esophagus. ESOPHAGUS /* inj *BURNS, CHEMICAL Electric burns of the hand. *HAND INJURIES *BURNS, ELECTRIC Fractures of the fibula. FIBULA /* inj *FRACTURES Ununited fractures of the arm. *ARM INJURIES *FRACTURES, UNUNITED 21.33 The concept "abnormalities" refers to structural congenital (rather than acquired) conditions appearing variously in the literature as "deformity", "anomaly", "malformation". The main heading ABNORMALITIES and the subheading /abnormalities will include the absence of organs, aplasia, agenesis, atresia, duplications of single organs, triplication of double organs and other anomalous or teratological states. 21.34 Index structural abnormalities of an organ under the subheading /abnormalities (IM) or under a specific abnormality heading from Category C16. See section 23.20+. Abnormalities of the pancreas. PANCREAS /* abnorm Agenesis of the lung. LUNG /*abnorm Mouth abnormalities. *MOUTH ABNORMALITIES (not MOUTH /*abnorm Heart abnormalities. *HEART DEFECTS, CONGENITAL Abnormalities of the tricuspid valve. TRICUSPID VALVE /* abnorm (do not index also under HEART DEFECTS,CONGENITAL) 21.35 Index the x-ray examination of an organ under the name of the organ with the subheading /radiography. In Category E1, however, are many pre- coordinated radiography terms (AORTOGRAPHY for AORTA/radiography) and many specific radiographic techniques (PNEUMORADIOGRAPHY, etc.). If a specific pre- coordinated radiography term is in MeSH, use that term instead of the organ with the subheading /radiography. X-ray of the liver. LIVER /* radiogr Pancreas radiography. PANCREAS /* radiogr Gallbladder x-ray. *CHOLECYSTOGRAPHY Radiography of veins. *PHLEBOGRAPHY Radiography of the femoral vein. FEMORAL VEIN /*radiogr (not also PHLEBOGRAPHY) 21.36 Index specific x-ray techniques for various organs under the name of the organ with the subheading /radiography (IM) and the specific technique (IM). Microradiography of the pancreas. PANCREAS /* radiogr *MICRORADIOGRAPHY 21.37 Although the widest application of the x-ray of an organ is in diagnosis, do not interpret an article or a discussion on the radiography of an organ as the diagnosis of a disease. Dacryocystography (x-ray of the lacrimal apparatus) LACRIMAL APPARATUS /*radiogr (not LACRIMAL APPARATUS DISEASES /*diag nor LACRIMAL APPARATUS DISEASES /*radiogr) It is possible to discuss the x-ray, x-raying or x-ray image of an organ without discussing its application to the x-ray or radiographic diagnosis of a disease. 21.38 Index the radionuclide imaging or ultrasonography of an organ under the name of the organ with the subheading /radionuclide imaging or /ultrasonography. Follow the procedures outlined above for radiography. Determination of kidney size by renal scintigraphy. KIDNEY / *radionuclide Ultrasonography of the liver in liver cirrhosis. LIVER / *ultrasonogr LIVER CIRRHOSIS /* ultrasonogr 21.39 Index foreign bodies of an organ under the name of the organ (IM), without a subheading, and FOREIGN BODIES (IM). There are so many objects and so much matter available as foreign bodies that no attempt in a medical thesaurus can be made to supply their names. The indexer, therefore, is seldom able to name the foreign body as a coordinate. Foreign bodies of the nose. *NOSE *FOREIGN BODIES Foreign bodies of the eye. *EYE FOREIGN BODIES 21.40 Index the presence of bacteria or fungi or Archaea in an organ under the name of the organ with the subheading /microbiology (IM) and the name of the organism with the subheading /isolation & purification (IM). Index the presence of a virus in an organ under the name of the organ with the subheading / virology (IM) and the name of the virus with the subheading / isolation & purification (IM). The presence of Klebsiella in the liver. LIVER /*microbiol KLEBSIELLA /*isol The isolation of Candida albicans from the skin. SKIN /* microbiol CANDIDA ALBICANS /*isol Detection of methanogens in the rumen of the cow. METHANOGENS /* isol RUMEN / * microbiol CATTLE / * microbiol ANIMAL ( check tag) Detection of rotaviruses in the intestines. INTESTINES /* virology ROTAVIRUS /* isol 21.41 Distinguish the presence of a microorganism in an organ from an infection of that organ. It is possible for an author to write about the presence of a microbe in body tissue without writing about an infection. For indexing purposes we make that distinction, although clinically the presence of an organism very often indicates an infection. See also section 22.11.1 for indexing infected cell lines or cultured cells. The presence of Salmonella in the liver. LIVER /* microbiol SALMONELLA /* isol (not LIVER DISEASES and SALMONELLA INFECTIONS) 21.42 Index the presence of parasites in organs, tissues, and body fluids under the name of the organ with the subheading /parasitology (IM) and the name of the parasite from Category B1 (IM). The presence of Dracunculus in the eye. DRACUNCULUS /* isol EYE /* parasitol (not DRACUNCULOSIS and EYE INFECTIONS, PARASITIC) 21.43 Distinguish the presence of a parasite in an organ from an infection of that organ. An author may discuss the presence of a parasite in an organ without discussing an infection by that organism. In many cases, however, an infection is discussed. 21.44 Use the subheading /parasitology and not /microbiology with an organ for protozoa in an organ. 21.45 Index the surgery of an organ under the name of the organ with the subheading /surgery (IM). Category E4 contains surgical procedures. Index under the Category E4 term instead of the organ/surgery if it is more specific. Surgery of the stomach. STOMACH /* surg Excision of the stomach. *GASTRECTOMY Surgery of the heart. *CARDIAC SURGICAL PROCEDURES (not HEART / surg) 21.46 Index the surgery of an organ in a disease of that organ treated surgically under the name of the organ with the subheading /surgery and the name of the disease with the subheading /surgery. The title of the article and the amount of discussion in the text will determine whether the organ/surgery combination is IM or NIM. Liver surgery in dicrocoeliasis of the liver. LIVER /* surg DICROCOELIASIS /* surg LIVER DISEASES, PARASITIC /* surg 21.47 BLOOD and PLASMA are both in Categories A12 and A15 but are used relatively infrequently as main headings since /blood is available as a subheading for diseases, drugs, many animals and some physiological states. Use the main heading BLOOD, when an author discusses blood as a substance. Plasma is used somewhat more often since it figures in blood transfusions. When used correctly BLOOD and PLASMA are IM. A new culture medium for anaerobes containing calf blood. *CULTURE MEDIA *BLOOD BACTERIA, ANAEROBIC /* growth CATTLE (check tag) ANIMAL (check tag) Levels of calcium in human blood. CALCIUM /*blood HUMAN (check tag) not BLOOD /* chem CALCIUM /* anal 21.48 HEART and MYOCARDIUM are often used interchangeably by authors. Differentiate between these two terms in the following way: if the organ is viewed as a pump, use HEART, if viewed as tissue, use MYOCARDIUM. 21.48.1 The subheadings that are permitted with Category A terms are listed below to show which may be used with HEART and which with MYOCARDIUM. Main heading/subheading combinations which are not allowed are also listed. /abnormalities = HEART DEFECTS, CONGENITAL /anatomy & histology = HEART /anatomy & histology /blood supply = CORONARY VESSELS /chemistry = MYOCARDIUM /chemistry /cytology = MYOCARDIUM /cytology /drug effects = HEART /drug effects /embryology = HEART /embryology /enzymology = MYOCARDIUM /enzymology /growth & development= HEART /growth & development /immunology = MYOCARDIUM /immunology /injuries = HEART INJURIES /innervation = HEART /innervation /metabolism = MYOCARDIUM /metabolism /microbiology = HEART /microbiology /parasitology = HEART /parasitology /pathology = MYOCARDIUM /pathology /physiology = HEART /physiology /physiopathology = HEART /physiopathology /radiation effects = HEART /radiation effects /radiography = HEART /radiography /radionuclide imaging = HEART /radionuclide imaging /secretion = do not use /surgery = CARDIAC SURGICAL PROCEDURES /transplantation =HEART TRANSPLANTATION /ultrasonography = ECHOCARDIOGRAPHY /ultrastructure = MYOCARDIUM /ultrastructure /virology = HEART / virology 21.49 Foreign bodies of the heart are indexed under FOREIGN BODIES (IM) and HEART, not HEART DISEASES. 21.50 The heart in pregnancy will most frequently be indexed under HEART, probably with the subheading /physiology and PREGNANCY /physiology (IM). 21.51 HEART ATRIUM and HEART VENTRICLE are MeSH headings but the nature of most articles on the heart requires viewing it as an entity, i.e., as HEART or MYOCARDIUM. For this reason HEART ATRIUM and HEART VENTRICLE will probably not be IM terms but merely NIM coordinates. MeSH has been annotated at HEART ATRIUM and HEART VENTRICLE. In addition to HEART ATRIUM and HEART VENTRICLE, there are specific ventricular function and atrial and ventricular disease terms in Categories G9 and C14. 21.52 PAPILLARY MUSCLES is often seen in articles on muscle experiments using the papillary muscles as test tissue. When this is the case, index under the main heading MUSCLES (with an appropriate subheading) as IM and make PAPILLARY MUSCLES (with the same subheading)NIM. Under third-tier indexing (20.11), it is possible that PAPILLARY MUSCLES may not be picked up at all. In any event do not index under HEART or MYOCARDIUM. If, however, the point of the article is the papillary muscles as part of the anatomy of the heart, PAPILLARY MUSCLES must be the term used. Calcium metabolism in muscle tissue. (Materials and methods indicates papillary muscles were used.) CALCIUM / * metab MUSCLES / * metab PAPILLARY MUSCLES / metab Papillary muscle function in ischemic heart disease. PAPILLARY MUSCLES /*physiopathol ISCHEMIC HEART DISEASE /* physiopathol 21.53 In articles on the human product of conception, EMBRYO will be used with reference to the first two months of pregnancy while FETUS will be used from the third month of pregnancy on. In articles on animals, follow the term used by the author, but remember FETUS is for mammals only. 21.54 EMBRYOLOGY is to be reserved for the discipline or embryologist only. Distinguish between EMBRYO and /embryology with organs in this way: if the article is on the embryo itself as an entity, as a whole or as tissue, use the heading EMBRYO. Use /embryology attached to an organ for the embryonic development or embryological aspects of that organ only. The effect of gamma rays on the mouse embryo. EMBRYO /* rad eff *GAMMA RAYS MICE (check tag) ANIMAL (check tag) The effect of gamma rays on the embryonic mouse liver. LIVER / *embryol / *rad eff MICE (check tag) ANIMAL (check tag) The effect of retinoic acid on Xenopus laevis embryos. RETINOIC ACID / *pharmacol EMBRYO, NON-MAMMALIAN / *drug eff XENOPUS LAEVIS ANIMAL (check tag) 21.55 In articles on the fetus, check the tag PREGNANCY only if the maternal aspect is discussed in the article. 21.56 Organs or tissue from organs are frequently used in research as representative of a particular type of tissue. For example, in studies of smooth muscle, the ileum is often used as a test tissue. When the organ is used in this manner, index under the specific tissue type (IM) and the organ (NIM) or not at all if it is third tier. The effect of pH on potassium ion transport in ileal muscle of the guinea pig. PH MUSCLE, SMOOTH /* metab ILEUM / metab ION TRANSPORT POTASSIUM /* metab GUINEA PIGS (check tag) ANIMAL (check tag) The function of the ileum in enteritis in humans. ILEUM / * physiopathol ENTERITIS /* physiopathol HUMAN (check tag) 21.57 CELLS, CULTURED including CELL LINE and all the terms treed under it in Category All are almost always NIM without a subheading because the concept almost always figures in an article as the vehicle in research. Index a cell line that is not in MeSH under CELL LINE, the check tag ANIMAL or HUMAN, the organ or tissue source if it is in the title or statement of purpose, and the specific animal for animal cell lines if it can be determined from the article. These terms will be NIM in most cases. If, however, the point of the article is the cell line then the term CELL LINE as well as the terms for the source will be IM. If a cell line is used to study a particular organ, the organ will be indexed IM probably with a subheading. A study of cell differentiation using a rat liver cell line. *CELL DIFFERENTIATION CELL LINE LIVER RATS (check tag) ANIMAL (check tag) (here the liver cell line is used to study the process of cell differentiation in general.) Comparison of cell differentiation in liver and kidney. (author indicates the study was done using rat liver and kidney cell lines) CELL LINE CELL DIFFERENTIATION LIVER /* cytol KIDNEY /*cytol ANIMAL (check tag) RATS (check tag) COMPARATIVE STUDY (check tag) (here the tissues LIVER and KIDNEY are the point of the article and are IM) Description of a new mouse adipocyte cell line. *CELL LINE ADIPOCYTES /* cytol *MICE ANIMAL (check tag) (here the cell line is the point of the article.) Follow the same policy for indexing CELLS, CULTURED and the specific cell culture terms treed under it such as TUMOR CELLS, CULTURED, CELL LINE, TRANSFORMED, etc. See section 24.4.5+ for a discussion of cultured tumor cells. The same principles apply to the indexing of TISSUE CULTURE (Category E5). See also above 21.56.