ABSTRACT
The quantification of endolymph volume by histological techniques or by magnetic resonance (MR) microscopy requires the inner ear to be first treated with chemical fixatives. If the fixative induces soft-tissue shrinkage, it would tend to return a distended Reissner's membrane towards a straight position, since this membrane is anchored to bone at its medial and lateral edges. The goal of this study was to determine the degree of Reissner's membrane shrinkage induced by different fixation protocols to establish methods which minimize tissue shrinkage. Fragments of fresh Reissner's membrane were dissected from isolated cochleae in an artificial perilymph. Specimens were viewed with an inverted microscope during infusion of fixatives, and changes recorded on video tape. Size changes of the specimen were quantified, usually over a 20 min period. Heidenhain-Susa, a fixative which is widely used in histological studies of hydropic cochleae, caused substantial shrinkage of Reissner's membrane, decreasing the length of specimens by an average of 15.1%. Other fixation procedures induced far less shrinkage. The use of 3.1% glutaraldehyde in Hanks' balanced salt solution produced a mean length decrease of only 0.3%. The inclusion in the fixation medium of 4.5% mercuric chloride, corresponding to the concentration which is present in Heidenhain-Susa and which acts to increase the contrast of Reissner's membrane in MR microscopy, contributes significantly to specimen shrinkage. We can conclude that the degree of endolymphatic hydrops may be underestimated in specimens fixed with media containing high levels of mercuric chloride.
Subject(s)
Cochlear Duct/anatomy & histology , Endolymph , Tissue Fixation , Animals , Cochlear Duct/pathology , Endolymphatic Hydrops/pathology , False Negative Reactions , Fixatives , Glutaral , Guinea Pigs , Isotonic Solutions , Mercuric Chloride , Perilymph , Videotape RecordingABSTRACT
Clinical and biological studies indicate that simian varicella virus (SVV) infection of primates is the counterpart of human varicella zoster virus (VZV) infection. We have identified an SVV open reading frame (ORF) that is homologous to the VZV protein IE62 and herpes simplex virus (HSV) ICP4. Like the genes encoding the VZV and HSV proteins, the SVV gene is located in the repeat region of the virus genome. Its expression in SVV-infected cells yields a 4.2-kb transcript. DNA sequencing of the SVV gene reveals a coding region 3834 nucleotides in length and a G+C content of 60.3%. Like ICP4 homologues in other herpesviruses, the SVV protein has five regions, two of which (regions 2 and 4) are highly conserved. The SVV protein also contains a run of serine residues in its amino terminus that is characteristic of herpesvirus ICP4 homologues. The SVV protein shows an overall homology of 24% to HSV ICP4 and 53% to VZV IE62.
Subject(s)
DNA, Viral/chemistry , Genes, Viral , Herpesvirus 3, Human/genetics , Immediate-Early Proteins/genetics , Simplexvirus/genetics , Trans-Activators/genetics , Viral Envelope Proteins/genetics , Viral Proteins/genetics , Amino Acid Sequence , Animals , Base Sequence , Blotting, Southern , Cell Line , Chlorocebus aethiops , DNA, Viral/genetics , Humans , Kidney , Molecular Sequence Data , Open Reading Frames , Sequence Homology, Amino Acid , Transcription, GeneticABSTRACT
Standards (95th, 50th, and 5th percentiles) in fragile X syndrome for weight, height, head circumference, ear length, and testicular volume are reported. For comparison with fragile X syndrome standardized curves, normal control data from the literature were similarly plotted and curves produced. These standards reflect the physical parameters that are frequently abnormal in males with the fragile X syndrome and should be useful in the medical management of patients with this syndrome. The standards may also be used to help identify those individuals, particularly the younger males, for chromosome studies to confirm the clinical impression of the fragile X syndrome.
