(n.) A commissure; especially, the optic commissure, or crucial union of the optic nerves.
Example Sentences:
(1) For the case described by the author primary tearing of the chiasma due to sudden applanation of the skull in the frontal region with burstfractures in the anterior cranial fossa is assumed.
(2) There were, however, significant differences among investigators in reported mean chiasma frequencies.
(3) In only one case was the B chromosome significantly associated with an increase chiasma frequency.
(4) Chromosomal analysis of cells undergoing diakinesis showed significantly lower chiasma frequency in elderly men, compared with a group of younger control males and also with infertile males.
(5) Furthermore we found increased chiasma frequencies in diakinesis--metaphase I (MI) and reduced nondisjunction frequencies at anaphse I as a result of the treatments applied.
(6) A case of cystic optic glioma involving chiasma and bilateral posterior optic pathway was reported.
(7) CT revealed a calcified lesion which must be a vessel in the chiasma cistern just adjacent to the basilar artery which was relatively larger than normal.
(8) In the unanaesthetised animals the proportions of units responding were high (60%) and did not differ significantly between regions for each type of stimulation investigated: visual, auditory and optic chiasma shocks.
(9) Tangential, centrifugal and incerta sedis-fibres, which originate either from cell bodies in the cell body layer at the periphery of the outer chiasma or more centrally, terminate in the synaptic region of the lamina.
(10) This new function is derived by assuming that all chromosome arms except the short arms of acrocentric chromosomes hav an obligatory chiasma, and that the remaining chiasmata are distributed at random; assumptions which may correspond reasonably well to reality.
(11) Thus from just beyond the chiasma the fibres had already achieved the major uniaxial rearrangement necessary to establish a normal tract distribution despite the eye translocation.
(12) Pathologically there was necrosis of the optic chiasma and focal areas of myelin sheath vacuolation or demyelination in certain areas of the brain, especially in the cerebellar peduncles.
(13) Predictions from the chiasma map can be confirmed or refuted only by genetic evidence for which the estimates of this paper serve as initial values to begin maximum likelihood iteration.
(14) Male meiosis in Mesostoma ehrenbergii ehrenbergii (2x = 10) is characterized by extreme restriction of chiasma formation; 3 pairs of chromosomes form bivalents at metaphase I which are associated by single very distally localized chiasma, while two pairs of chromosomes remain as unpaired univalents.
(15) It was found that both of the heat-induced decreases in chiasma frequency which can be obtained (Effects 2 and 3), were dominant over both of the different types of increase (Effects 1 and 4), with the largest decrease (Effect 3) being dominant over all others.
(16) In precocious puberty we found 1 ectopic pinealoma and 2 gliomas of the chiasma.
(17) The latter refers to the Willis atypical polygons, which determine important atipies in the topographical distribution of the chiasma's arteries and optical bandelets.
(18) In the rostral third of the SCN there are relatively few optic synapses which are found close to the optic chiasma.
(19) In addition to this abnormality there is a misrouting of the optic nerve fibers, with some fibers from the temporal retina following a crossed route at the chiasma and terminating in the contralateral cortical hemisphere.
(20) The chiasma frequency estimates were based on 15 son-sire pairs, the translocation heterozygotes being maintained in a Swiss random-bred genetic background.
Chromosome
Definition:
(n.) One of the minute bodies into which the chromatin of the nucleus is resolved during mitotic cell division; the idant of Weismann.
Example Sentences:
(1) In contrast, DNA polymerase alpha, the enzyme involved in chromosomal DNA replication, was relatively insensitive to CA1.
(2) Here we report that sperm from psr males fertilizes eggs, but that the paternal chromosomes are subsequently condensed into a chromatin mass before the first mitotic division of the egg and do not participate in further divisions.
(3) Clonal abnormalities involving chromosomes 3 and 21 were noted in two patients.
(4) Five probes of high specificity to individual chromosomes (chromosomes 3, 11, 17, 18 and X) were hybridized in situ to metaphase chromosomes of different individuals.
(5) The constitution of chromosomes in the two plasmacytomas remained remarkably stable in their homogeneous modal population.
(6) The data on mapping the episomal plasmid integration sites in yeast chromosomes I, III, IV, V, VII, XV are presented.
(7) The purpose of these studies was to better understand the molecular basis of chromosome aberration formation after mitomycin C treatment.
(8) Twelve families with Wiskott-Aldrich syndrome (WAS) were studied by linkage analysis using 10 polymorphic marker loci from the X-chromosome pericentromeric region.
(9) The effects of phenoxyacetic acid herbicides were investigated on the induction of chromosome aberrations in human peripheral lymphocyte cultures in vitro and in lymphocytes of exposed workers in vivo.
(10) Pituitary weight, mitotic index and chromosomes were studied in male rats following a single or repeated dose of estradiol-benzoate for a total period of 210 days.
(11) Alleles in this region can be exchanged between X and Y chromosomes and are therefore inherited as if autosomal.
(12) The haplotype of the recombinant X chromosome of each of 241 backcross progeny has been established using the X-linked anchor loci Otc, Hprt, Dmd, Pgk-1, and Amg and the additional probes DXSmh43 and Cbx-rs1.
(13) In the triploids, the 40 female chromosomes present (mouse, n = 20) were derived from a single diploid pronucleus formed after the extrusion of a first polar body, and following the monospermic fertilization of primary oocytes.
(14) The induction of cells with two Y chromosomes by nitrogen mustard (NM) was examined.
(15) Several investigators have attempted to correlate chromosomal abnormalities with Cornelia de Lange Syndrome (CLS), but none of them have been conclusive.
(16) The technique resolved chromosomes in the size range of 100 kb-1 Mb.
(17) A number of recurring chromosomal abnormalities have been identified in childhood acute lymphoblastic leukemia.
(18) Since the plasmid-cured strains did not contain DNA sequences homologous to plasmid DNA, the gene for the free-inclusion protein must be encoded in the chromosome.
(19) The gene, which is located at chromosome XIII, is transcribed as a mRNA of about 2.7 kilobases, and the amount of message has been found to increase 3- to 4-fold during the culture.
(20) The numerical chromosome values in 53 human tumors were determined and compared with the modal DNA values as measured by flow cytometry.