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Medical Dictionary


schistocormia (skis-to-kor′me-a)
Congenital clefting of the trunk, the lower extremities of the fetus usually being imperfectly developed. SYN: schistosomia. [schisto- + G. kormos, trunk of a tree]

schistocystis (skis-to-sis′tis)
Fissure of the bladder. [schisto- + G. kystis, bladder]

schistocyte (skis′to-sit)
A variety of poikilocyte that owes its abnormal shape to fragmentation occurring as the cell flows through damaged small vessels. SYN: schizocyte. [schisto- + G. kytos, cell]

schistocytosis (skis′to-si-to′sis)
The occurrence of many schistocytes in the blood. SYN: schizocytosis.

schistoglossia (skis-to-glos′e-a)
Congenital fissure or cleft of the tongue. [schisto- + G. glossa, tongue]

schistomelia (skis′to-mel′e-a)
Congenital cleft of a limb.

schistorrhachis (skis-tor′a-kis)
SYN: spina bifida. [schisto- + G. rhachis, spine]

Schistosoma (skis-to-so′ma)
A genus of digenetic trematodes, including the important blood flukes of humans and domestic animals, that cause schistosomiasis; characterized by elongate shape, by separate sexes with marked sexual dimorphism, by their unusual location in the smaller blood vessels of their host, and by utilization of water snails as intermediate hosts. [schisto- + G. soma, body] S. haematobium the vesical blood fluke, a species with terminally spined eggs that occurs as a parasite in the portal system and mesenteric veins of the bladder (causing human schistosomiasis haematobium) and rectum; common in the Nile delta but is found along waterways, irrigation ditches, or streams throughout Africa and in parts of the Middle East; the intermediate host is Bulinus truncatus in Egypt; elsewhere, other snails of the subfamily Bulininae (Bulinus, Physopsis, Pyrgophysa) are involved. S. intercalatum a blood fluke species related to S. haematobium locally distributed in Zaire and other areas of central Africa, causing mild dysentery and abdominal pains, with enlargement of the spleen and liver; a planorbid snail, Bulinus (Physopsis) africanus, serves as the intermediate host. S. japonicum the Oriental or Japanese blood fluke, a species having eggs with small lateral spines, usually only a small knob; causes schistosomiasis japonica, with extensive pathology from encapsulation of the eggs, particularly in the liver, and is the most pathogenic of the three common schistosome species afflicting man, possibly owing to greater egg production per female worm; it is also the most intractable to treatment and the most difficult to control, as the intermediate hosts are amphibious snails (species of Oncomelania, family Hydrobiidae) that can leave the water to avoid molluscicides, and also because many other animals, such as pigs, oxen, cattle, and dogs, serve as reservoir hosts. S. malayensis a member of the S. japonicum complex described from the rodent Rattus muelleri in peninsular Malaysia. The aquatic snail Robertsiella kaporensis and two other species of this genus were found to be naturally infected. S. malayensis is considered most closely related to S. mekongi. Human infections, based on serologic evidence, were reported among the indigenous people of central peninsular Malaysia. S. mansoni a common species of trematode characterized by large eggs with a strong lateral spine and transmitted by planorbid snails of the genus Biomphalaria; causes schistosomiasis mansoni in humans in Africa, parts of the Middle East, South America, and certain Caribbean islands. S. mattheei a species found in the portal and mesenteric veins of ruminants, primates (including humans), zebra, and rodents in Africa. S. mekongi the Mekong schistosome, a species described from the Mekong delta in southern Laos and northern Cambodia. Infection rates are highest for ages 7–15; dogs appear to be the chief reservoir host; the intermediate host snail is the operculid snail, Tricula aperta. Pathology is similar to but generally less severe than that of S. japonicum.

schistosome (skis′to-som)
Common name for a member of the genus Schistosoma.

schistosomia (skis-to-so′me-a)
SYN: schistocormia. [schisto- + G. soma, body]

schistosomiasis (skis′to-so-mi′a-sis)
Infection with a species of Schistosoma; manifestations of this often chronic and debilitating disease vary with the infecting species but depend in large measure upon tissue reaction (granulation and fibrosis) to the eggs deposited in venules and in the hepatic portals, the latter resulting in portal hypertension and esophageal varices, as well as liver damage leading to cirrhosis. See tropical diseases, under disease. SEE ALSO: schistosomal dermatitis, Symmers clay pipestem fibrosis. SYN: bilharziasis, bilharziosis, hemic distomiasis, snail fever. Asiatic s. SYN: s. japonica. bladder s. SYN: s. haematobium. cutaneous s. japonica SYN: s. japonica. ectopic s. a clinical form of s. that occurs outside of the normal site of parasitism (mesenteric vein or hepatic portals); may result from accidental blood-borne transport of schistosome eggs or, rarely, adult worms, to various unusual sites such as the skin, brain, or spinal cord. s. haematobium infection with Schistosoma haematobium, the eggs of which invade the urinary tract, causing cystitis and hematuria, and possibly an increased likelihood of bladder cancer. SYN: bladder s., Egyptian hematuria, endemic hematuria, urinary s.. S. intercalatum infection with Schistosoma intercalatum; occurs only in West Africa; few symptoms reported and no cases of hepatic fibrosis known. intestinal s. SYN: s. mansoni. s. japonica, Japanese s. infection with Schistosoma japonicum, characterized by dysenteric symptoms, painful enlargement of the liver and spleen, dropsy, urticaria, and progressive anemia. SYN: Asiatic s., cutaneous s. japonica, kabure itch, kabure, Katayama syndrome, Kinkiang fever, Oriental s., rice itch, urticarial fever, Yangtze Valley fever. Manson s. SYN: s. mansoni. s. mansoni infection with Schistosoma mansoni, the eggs of which invade the wall of the large intestine and the liver, causing irritation, inflammation, and ultimately fibrosis. SYN: intestinal s., Manson disease, Manson s.. s. mekongi infection with Schistosoma mekongi, which chiefly afflicts children in the Mekong delta, where it was discovered; the disease is similar to s. japonica. Oriental s. SYN: s. japonica. pulmonary s. pulmonary manifestations of infection with Schistosoma, usually Schistosoma mansoni, occurring when schistosomals, which form in the skin from the cercariae which have entered from infected water, migrate via the bloodstream to the lungs, en route to the gastrointestinal tract and the portal vein; symptoms are usually limited to cough. urinary s. SYN: s. haematobium.

schistosomulum, pl .schistosomula (skis-to-so′mu-lum, -la)
The stage in the life cycle of a blood fluke of the genus Schistosoma immediately after penetration of the skin as a cercaria; marked by loss of the tail and gaining of physiological modifications allowing it to survive in a mammalian bloodstream.

schistosternia (skis-to-ster′ne-a)
SYN: schistothorax. [schisto- + G. sternon, sternum]

schistothorax (skis-to-thor′aks)
Congenital cleft of the chest wall. SYN: schistosternia. [schisto- + G. thorax, thorax]

See schizo-.

schizamnion (skiz-am′ne-on)
An amnion developing, as in the human embryo, by the formation of a cavity over or within the inner cell mass. [schiz- + amnion]

schizaxon (skiz-ak′son)
An axon divided into two branches. [schiz- + G. axon, axis]

schizencephaly (skiz-en-sef′a-le)
Abnormal divisions or clefts of the brain substance. [schiz- + G. enkephalos, brain]

schizo-, schiz-
Split, cleft, division; schizophrenia. SEE ALSO: schisto-. [G. schizo, to split or cleave]

schizo-affective (skiz′o-a-fek′tiv)
Having an admixture of symptoms suggestive of both schizophrenia and affective (mood) disorder.

schizocyte (skiz′o-sit)
SYN: schistocyte. [schizo- + G. kytos, cell]

schizocytosis (skiz′o-si-to′sis)
SYN: schistocytosis.

schizogenesis (skiz-o-jen′e-sis)
Reproduction by fission. SYN: fissiparity, scissiparity. [schizo- + G. genesis, origin]

schizogony (ski-zog′o-ne)
Multiple fission in which the nucleus first divides and then the cell divides into as many parts as there are nuclei; called merogony if daughter cells are merozoites, sporogony if daughter cells are sporozoites, or gametogony if daughter cells are gametes. SYN: agamocytogeny. [schizo- + G. gone, generation]

schizogyria (skiz-o-ji′re-a, -jir′e-a)
Deformity of the cerebral convolutions marked by occasional interruptions of their continuity. [schizo- + G. gyros, circle (convolution)]

schizoid (skiz′oyd)
Socially isolated, withdrawn, having few (if any) friends or social relationships; resembling the personality features characteristic of schizophrenia, but in a milder form. SEE ALSO: s. personality. [schizo(phrenia), + G. eidos, resemblance]

schizoidism (skiz′oy-dizm)
A schizoid state; the manifestation of schizoid tendencies.

schizomycete (skiz′o-mi-set)
A member of the class Schizomycetes; a bacterium.

schizomycetic (skiz-o-mi-se′tik)
Relating to or caused by fission fungi (bacteria).

schizont (skiz′ont)
A sporozoan trophozoite (vegetative form) that reproduces by schizogony, producing a varied number of daughter trophozoites or merozoites. SEE ALSO: meront, segmenter. SYN: agamont, segmenting body. [schizo- + G. on (ont-), a being]

schizonticide (ski-zon′ti-sid)
An agent that kills schizonts. [schizont + L. caedo, to kill]

schizonychia (skiz-o-nik′e-a)
Splitting of the nails. [schizo- + G. onyx, nail]

schizophasia (skiz-o-fa′ze-a)
A rarely used term for the disordered speech (word salad) of the schizophrenic individual. [schizo- + G. phasis, speech]

schizophrenia (skiz-o-fre′ne-a, skit′so-)
A term coined by Bleuler, synonymous with and replacing dementia praecox; a common type of psychosis, characterized by abnormalities in perception, content of thought, and thought processes (hallucinations and delusions) and by extensive withdrawal of interest from other people and the outside world, with excessive focusing on one's own mental life; now considered a group or spectrum of disorders rather than a single entity, with distinction sometimes made between process s. and reactive s.. The “split” personality of s., in which individual psychic components or functions split off and become autonomous, is popularly but erroneously identified with multiple personality, in which 2 or more relatively complete personalities dominate by turns the psychic life of an individual. [schizo- + G. phren, mind] S. is the most prevalent psychosis, affecting some 2 million Americans. The annual cost of the disease to the U.S. economy is estimated at $65 billion, of which $46 billion reflects lost productivity of patients and their caregivers. The lifetime incidence risk is about 1%. Onset is typically gradual, without an obvious precipitating cause. Early symptoms include shortened attention span, memory deficits, and diminished ability to make decisions. Most patients become ill before age 40. Psychotic symptoms persist for months or years, and there is a lifelong risk of relapse. Cognitive malfunctions are typically accompanied by reduced energy level, flat or depressed affect, anhedonia, and abulia. Virtually all patients display impoverished thought content, social withdrawal, and impairment of occupational functioning, and even with intensive psychotherapy and drug treatment about 25% require custodial or institutional care. Although some persons with s. become assassins or mass murderers, the vast majority pose no threat to society; about 10% commit suicide. Neurophysiologic studies have shown generalized limbic lobe and prefrontal cortical abnormalities, abnormal smallness of the thalamus, and changes in signal intensity in adjacent white matter. Brain imaging inconsistently demonstrates structural or physiologic abnormalities in the prefrontal cortex, cingulate cortex, temporal cortex, and hippocampal formation. The amelioration or exacerbation of s. by certain pharmacologic agents seems to indicate that it represents a malfunction of neuronal systems using dopamine, serotonin, glutamate, and γ-aminobutyric acid (GABA) as transmitters or modulators. Genetic studies suggest that susceptibility to s. is inherited as a complex of variations affecting several genes. According to the neurodevelopmental hypothesis, a brain lesion is present or acquired early in life but does not fully manifest itself until late adolescence or early adulthood, when it triggers abnormalities of neuronal proliferation, axonal outgrowth, cell migration, cell survival, synaptic regression, or myelination. Psychotherapy and behavioral therapy are inconsistently effective in the treatment of s.. Neuroleptic drugs shorten episodes of acute psychosis, limit the need for institutional care, and reduce the risk of relapse, but their long-term use is associated with serious side effects, particularly tardive dyskinesia. Newer agents such as clozapine, olanzipine, quetiapine, and risperidone are more effective in improving cognitive function and less likely to induce extrapyramidal side effects. Persons with s. frequently stop taking their medicine, and it is estimated that at any given time only one-half of them are receiving medical treatment or supervision. acute s. a disorder in which the symptoms of s. occur abruptly; they may subside or become chronic over time. SYN: acute schizophrenic episode. ambulatory s. a milder form of s. in which the patient is capable of maintaining himself or herself in society and need not be hospitalized. catatonic s. s. characterized by marked disturbance, which may involve stupor, negativism, rigidity, excitement, or posturing; sometimes there is rapid alternation between the extremes of excitement and stupor. Associated features include stereotypic behavior, mannerisms, and waxy flexibility; mutism is particularly common. childhood s. SYN: infantile autism. disorganized s. a severe form of s. characterized by the predominance of incoherence, blunted, inappropriate or silly affect, and the absence of systematized delusions. SYN: hebephrenic s.. hebephrenic s. SYN: disorganized s.. latent s. a preexisting susceptibility for developing overt s. under strong emotional stress. paranoid s. s. characterized predominantly by delusions of persecution and megalomania. process s. an obsolete term for those forms of severe schizophrenic disorders in which chronic and progressive biologic conditions in the brain are considered to be the primary cause and in which prognosis is poor as well, with insidious onset at a young age, as contrasted with reactive s.. pseudoneurotic s. s. in which the underlying psychotic process is masked by complaints ordinarily regarded as neurotic. reactive s. those forms of severe schizophrenic disorders which are distinguished from process s. by their more acute onset, greater relation to environmental stress, and better prognosis. residual s. blunted or inappropriate affect, social withdrawal, eccentric behavior, or loose associations, but without prominent psychotic symptoms, as the remains of former psychotic symptoms of s.. simple s. s. characterized by withdrawal, apathy, indifference, and impoverishment of human relationships without overt psychotic features.

schizophrenic (skiz-o-fren′ik, -fre′nik, skit-so-)
Relating to, characteristic of, or suffering from one of the schizophrenias.

schizotonia (skiz-o-to′ne-a)
Division of the distribution of tone in the muscles. [schizo- + G. tonos, tension, tone]

schizotrichia (skiz-o-trik′e-a)
A splitting of the hairs at their ends. SYN: scissura pilorum. [schizo- + G. thrix, hair]

Schizotrypanum cruzi (skiz-o-tri′pan-um kroo′zi)
A distinct generic designation used for Trypanosoma cruzi, used frequently by workers in the endemic area of South American trypanosomiasis; also used as a subgeneric designation, i.e., Trypanosoma (Schizotrypanum) cruzi. [schizo- + G. trypanon, a borer, an auger]

schizozoite (skiz-o-zo′it)
A merozoite prior to schizogony, as in the exoerythrocytic phase of the development of the Plasmodium agent after sporozoite invasion of the hepatocyte and before multiple division. [schizo- + G. zoon, animal]

schlammfieber (shlam′fe-ber)
Name given to an outbreak of leptospirosis near Breslau in Germany thought to have been due to infection with Leptospira grippotyphosa.

Carl B., Swiss surgeon, 1864–1934. See Osgood-S. disease.

Friedrich, German anatomist, 1795–1858. See S. canal.

Hermann, Austrian physician, 1868–1934. See S. sign, Pool-S. sign.

schlieren (schler′en)
See s. optics.

Rudi, Swiss-U.S. internist and biochemist, *1922. See McArdle-S.-Pearson disease.

W. See S.-Fraccaro syndrome.

Kasimir C., German anatomist, 1718–1792. See S. anastomoses, under anastomosis.

Gerhard, U.S. biochemist, *1900. See S.-Thannhauser method.

Henry D., U.S. anatomist and pathologist, 1823–1888. See S.-Lanterman clefts, under cleft, S.-Lanterman incisures, under incisure.

Johann F.M., German laryngologist, 1838–1907. See S. syndrome.

Martin Benno, German physician, 1863–1949. See S. syndrome.

Christian G., German pathologist, 1861–1932. See S. nodule, S. ferric-ferricyanide reduction stain, S. picrothionin stain, S. jaundice.

C.V., German anatomist, 1614–1680. See schneiderian membrane.

Franz C., German chemist, 1813–1897. See S. carmine.

Kurt, German psychiatrist, 1887–1967.

Schneidersitz (shni′der-zitz)
A typical sitting position with legs crossed in front, exhibited by severely defective patients with phenylketonuria and resembling the position which was commonly attributed to tailors. [Ger.]

L., 20th century European physician. See S. syndrome.

Per F., Norwegian physiologist, 1905–1980. See S. apparatus, Roughton-S. apparatus, Roughton-S. syringe.

Willibald, German neurologist, 1889–1971. See S. disease.

Christian F., German chemist, 1799–1868. See S. test.

Johann L., German physician, 1793–1864. See S. purpura, Henoch-S. purpura.

school (skool)
A set of beliefs, teachings, methods, etc. [O. E. scol] biometrical s. a group of British geneticists, followers of Galton and Karl Pearson, whose approach to genetics was quantitative rather than enumerative. iatromathematical s. a group of academicians, of whom Descartes was one of the foremost proponents, who maintained that all physiologic processes were the result of physical laws. SYN: mechanistic s.. mechanistic s. SYN: iatromathematical s..

Theodor, 1850–1921, German physician in Bad Nauheim. See S. treatment.

schradan (schra′dan)
A potent irreversible organophosphate cholinesterase inhibitor used as an insecticide. It was prepared for potential use as a nerve gas. Poisoning produces a cholinergic crisis which can be fatal. SYN: octamethyl pyrophosphoramide. [Gerhard Schrader, Ger. chemist, + -an]

Christian H.T., German anatomist and chemist, 1768–1833. See S. lines, under line, Hunter-S. bands, under band, Hunter-S. lines, under line.

Hermann R.A., German pathologist, *1876. See S. cancer hairs, under hair.

Karl L.E., German gynecologist, 1838–1887. See S. operation.

Karl A., German surgeon, 1856–1902. See S. operation.

Wilhelm, German pathologist in Sumatra, 1867–1949. See S. granules, under granule, S. dots, under dot.

Karl H.L.A. Max, German surgeon, 1843–1907. See S. ducts, under duct.

Artur, Austrian neurologist, *1874. See S. disease, S. phenomenon, S. syndrome, Hand-S.-Christian disease.

Johann. See Scultetus.

Werner, German internist, 1878–1947. See S.-Charlton phenomenon, S.-Charlton reaction, S.-Dale reaction.

Arthur R.H., German physician, *1890. See S. reaction, S. stain.

Max J.S., German histologist and zoologist, 1825–1874. See S. cells, under cell, S. membrane, S. sign, comma bundle of S., comma tract of S..

Bernhard S., German obstetrician, 1827–1919. See S. fold, S. mechanism, S. phantom, S. placenta.

Erich, German biochemist, *1902. See S. law, S. rule.

Hugo, 19th century German anatomist. See S. bundle.

Dagobert, German otologist, 1846–1920. See S. test.

Gustav A., German anatomist, 1844–1916. See S. corpuscle, S. nucleus, S. ring, S. spaces, under space.

Theodor, German histologist and physiologist, 1810–1882. See S. cells, under cell, S. cell unit, S. white substance, sheath of S..

schwannoma (shwah-no′ma)
A benign, encapsulated neoplasm in which the fundamental component is structurally identical to a syncytium of Schwann cells; the neoplastic cells proliferate within the endoneurium, and the perineurium forms the capsule. The neoplasm may originate from a peripheral or sympathetic nerve, or from various cranial nerves, particularly the eighth nerve; when the nerve is small, it is usually found (if at all) in the capsule of the neoplasm; if the nerve is large, the neurilemoma may develop within the sheath of the nerve, the fibers of which may then spread over the surface of the capsule as the neoplasm enlarges. Microscopically, neurilemoma is composed of combinations of two patterns, Antoni types A and B, either of which may be predominant in various examples of neurilemomas. SEE ALSO: neurofibroma. SYN: neurilemoma, neuroschwannoma. [Theodor Schwann + -oma] acoustic s. SYN: vestibular s.. vestibular s. a benign but life-threatening tumor arising from Schwann cells, usually of the vestibular division of the eighth cranial nerve; produces hearing loss, tinnitus, and vestibular disturbances, early and cerebellar, brainstem, and other cranial nerve signs and increased intracranial pressure in late stages. SYN: acoustic neurinoma, acoustic neuroma, acoustic s., acoustic tumor, cerebellopontine angle tumor, eighth nerve tumor.


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