Roland C. Rouse

Pathology of neuroepithelial suprastructures of the human inner ear.

Neuroepithelial suprastructures in abnormal human inner ears were studied by light microscopy, scanning electron microscopy, and x-ray diffraction. The most common abnormality was calcification, which selectively affected the gelatinous membranes (otoconial, cupular, and tectorial) and the secretory tissues (stria vascularis and utricular dark cells). The structures most frequently affected were the otoconial membranes. The minerals involved were apatite, octacalcium phosphate, and vaterite, replacing the normal layer of calcium carbonate in the form of calcite crystals. The first two of these substances were sometimes mixed with calcite. In the saccule such abnormal otoconial deposits were usually associated with a collapsed saccular wall. Formation of abnormal otoconia is characterized as primary (no pre-existing normal calcite otoconia) or secondary (formed after the destruction of normal otoconia). Such deposits probably depend upon an abnormal composition of the endolymph, especially upon an elevated concentration of phosphate ions. It is inferred that a normal endolymphatic microhomeostasis is necessary to maintain the functional state of the neuroepithelial suprastructures.

Crystal structure of boralsilite and its relation to a family of boroaluminosilicates, sillimanite, and andalusite

Abstract Boralsilite, Al16B6Si2O37, is monoclinic, space group C2/m, with a = 14.767(1), b = 5.574(1), c = 15.079(1) Å, β = 91.96(1)°, and Z = 2. The structure was solved with direct methods and refined to an unweighted residual of 0.026 using 1193 observed reflections. The structure is closely related to those of sillimanite, andalusite, grandidierite, synthetic aluminum borate (Al18B4O33), and werdingite. These structures are all based on a backbone of chains of edge-sharing AlO6 octahedra arranged parallel to c (≅ 5.6 Å) and at the vertices and center of a pseudo-tetragonal subcell having a ≅ b ≅ 7.5 Å. In the boralsilite structure, AlO6 octahedral chains are cross-linked by Si2O7 disilicate groups, BO4 tetrahedra, BO3 triangles, and AlO5 trigonal bipyramids. A given BO4 or SiO4 tetrahedron or BO3 triangle shares two vertices with two adjacent AlO6 octahedra of one chain and a third vertex with an octahedron vertex of an adjacent chain, thus cross-linking the AlO6 octahedral chains. Further linkage is provided through vertex-sharing of AlO5 trigonal bipyramids. These bipyramids alternate with B or Si polyhedra parallel to AlO6 octahedral chains to form four kinds of cross-linking chains of polyhedra, with alternate atom pairs [5]Al1-Si, [5]Al2-[4]B2, [5]Al3-[3]B1, and [5]Al4-[3]B3. The units which cross-link between chains of AlO6 octahedra can alternatively be viewed as consisting of Si2O7 dimers, trimers of edge-sharing AlO5 trigonal bipyramids (plus a B triangle and B tetrahedron), and dimers of edge-sharing AlO5 trigonal bipyramids (plus B triangles and tetrahedra), Variations on these themes are found in the structures of sillimanite, andalusite, grandidierite, werdingite, mullite, and synthetic Al18B4O33. The interchangeability and variety of the various interchain units appears to result in part from the flexibility produced by the ability of Al and B to assume a variety of coordinations by oxygen and from the potential for partial vacancy of some anion and cation sites.

The structure of thorikosite, a naturally occurring member of the bismuth oxyhalide group

Abstract Thorikosite, (Pb 3 Sb 0.6 As 0.4 )(O 3 0H)Cl 2 , is a naturally occurring member of the bismuth oxyhalide group isostructural with LiBi 3 O 4 Cl 2 . The space group is I4/mmm with a = 3.919(1)A˚ , c = 12.854(5)A˚ , and Z = 1 . A crystal structure analysis showed complete solid solution of Pb 2+ , Sb 3+ , and As 3+ on the single cation site and large atomic temperature factors indicative of pervasive structural disorder. The latter is due to the structural adjustments necessary to accommodate cations of very different sizes in the same site. Thorikosite is closely related to synthetic tetragonal PbSbO 2 Cl through the coupled substitution Sb 3+ O 2− ⇌ Pb 2+ (OH) − .

Destinezite ("diadochite"), Fe 2 (PO 4 )(OH).6H 2 O; its crystal structure and role as a soil mineral at Alum Cave Bluff, Tennessee

A new occurrence of destinezite (diadochite), ideally Fe2(PO4)(SO4)(OH)-6H2O, is described from Alum Cave Bluff, Great Smoky Mountains National Park, Tennessee, where it occurs in soil and in a weathered Precambrian phyllite in unusually large crystals associated with other hydrated sulfates such as pickeringite-apjohnite. Destinezite is triclinic, P1̄, with a = 9.570(1), b = 9.716(1), c = 7.313(1) Å, α = 98.74(1)°, β = 107.90(1)°, γ = 63.86(1)° and Z = 2. Its crystal structure consists of infinite chains of Fe(O,OH,H2O)6 octahedra, sulfate tetrahedra and phosphate tetrahedra linked by a unique system of vertex sharing. The chains are weakly bonded into slabs by hydrogen bonding between OH and H2O of the Fe(III) octahedra and oxygen ions of the sulfate tetrahedra. Slabs of tetrahedral/octahedral chains alternate with sheets of H2O molecules. The structure thus somewhat resembles hydrated clay minerals, with H2O molecules that act as hydrogen bond donors and acceptors to oxygen atoms of adjacent slabs. Destinezite and diadochite occur at numerous localities worldwide and have been assumed to be identical, but this identity has never been proven. It is proposed that the name “destinezite” be applied to visibly crystalline, triclinic Fe2(PO4)(SO4)(OH).6H2O and “diadochite” to massive to earthy, poorly ordered, X-ray amorphous materials that approximate destinezite in composition. Diadochite/destinezite may be an unrecognized component of soils where weathering of pyrite and apatite has occurred and pH is low. It may thus be a significant sink for phosphorus and sulfur in such soils.

The new minerals levinsonite-(Y) [(Y, Nd,Ce)Al(SO4)2(C2O4) · 12H2O] and zugshunstite-(Ce) [(Ce,Nd,La)Al(SO4)2(C2O4) · 12H2O]: Coexisting oxalates with different structures and differentiation of LREE and HREE>

Abstract Two new minerals, levinsonite-(Y) [(Y,Nd,Ce)Al(SO 4 ) 2 (C 2 O 4 ) · 12H 2 O] and zugshunstite-(Ce) [(Ce,Nd,La)Al(SO 4 ) 2 (C 2 O 4 ) · 12H 2 O], occur in an evaporite assemblage at Alum Cave Bluff, Great Smoky Mountains National Park, Tennessee. Electron microprobe analyses with oxalate and water assumed as stoichiometric yield the formula Y 0.33 La 0.02 Ce 0.12 Pr 0.03 Nd 0.23 Sm 0.12 Eu 0.02 Gd 0.08 Dy 0.04 Er 0.01 Al(SO 4 ) 2 (C 2 O 4 ) · 12H 2 O for levinsonite-(Y) and Y 0.00 La 0.09 Ce 0.54 Pr 0.07 Nd 0.26 Sm 0.03 Eu 0.01 Gd 0.01 Dy 0.00 Er 0.00 Al(SO 4 ) 2 (C 2 O 4 ) · 12H 2 O for zugshunstite-(Ce). Smaller ions such as Y and several MREE to HREE are enriched in the former phase, whereas the LREE are concentrated in the latter phase. The two minerals occur in intimate contact, with low-temperature conditions favoring MREE in levinsonite-(Y) and LREE in zugshunstite-(Ce). The crystal structures are based on the same fundamental building blocks, chains of alternating REE polyhedra and oxalate groups, with two sulfate tetrahedra attached to each REE polyhedron. The REE polyhedron in levinsonite-(Y) is a square antiprism defined by eight ligands ( = 2.404 A), whereas that in zugshunstite-(Ce) is a nine-fold cooordinated capped square antiprism ( = 2.507 A). The polyhedra resemble those in xenotime and monazite, respectively. The addition of one ligand in zugshunstite-(Ce) into the capping position results in relative shifts of the chains, isolated water molecules, and isolated Al(H 2 O) 6 octahedra relative to their positions in the levinsonite-(Y) structure. The source of the REE elements is likely to be the weathering of pyritiferous schist, which is reported to contain monazite and xenotime. Chelation of REE and Al by oxalate under hydrous conditions at surface temperature permits formation of the minerals.

Four variations of the mondini inner ear malformations as seen in microdissections

Four variations and degrees of severity of the Mondini malformation were found in the temporal bones from two neonates, one with congenital heart disease and the other with trisomy D, and from one teenager with leukemia: 1) short cochlea and normal vestibular organs; 2) short cochlea and persistent horizontal canal anlage; 3) markedly shortened cochlea with no modiolus, wide internal auditory meatus, and persistent horizontal canal anlage; 4) same as variation 3, but with persistent anlagen in all semicircular canals. Variations 3 and 4 were from the case of trisomy D, in which the left cochlea had a normal hair cell population but few nerve fibers, and the intraganglionic spiral bundle was displaced from Rosenthals canal to the osseous spiral lamina. The right ear had no cochlear nerve fibers; the organ of Corti was present, but hair cells were unusually small. In the case of trisomy D, both ears showed subtotal loss of vestibular nerve fibers. Although the rudimentary cristae of the right ear had numerous hair cells, the macular hair cells were fewer and malformed. No hydrops was present.

Sensorineural and vascular changes in an ear with acoustic neurinoma.

The temporal bones from a 55-year-old woman with deafness and dizzy spells caused by a right-sided acoustic neurinoma were examined by the techniques of microdissection, surface preparations, and celloidin sections. Sensorineural degeneration was present in the basal end of the right cochlea but was not severe enough to explain the deafness. The compression of the cochlear nerve by the tumor was postulated to have caused deafness by injury to neurons adjacent and central to the tumor. There was profound degeneration of the vestibular nerve and sensory cells. A gelatinous material occluded the scala vestibuli, and the vestibular fluid spaces contained an amorphous proteinaceous substance. Fewer erythrocytes were seen in the vessels of the right cochlea, but there was no atrophy of capillaries to indicate long-term reduction of circulation. Vasculoneogenesis of venous vessels had occurred in the scala tympani, probably as a result of venous stasis.

Hereditary deafness with hydrops and anomalous calcium phosphate deposits

The temporal bones from a 58-year-old white woman who had had hereditary congenital deafness were examined with the techniques of microdissection and surface preparations followed by sectioning of the modiolus. There was bilateral, almost total sensorineural degeneration, which also involved the saccule. The degeneration of the distal processes of the cochlear neurons in the osseous spiral lamina was almost complete, whereas numerous ganglion cells and proximal processes remained in the modiolus and the internal auditory canal. Severe cochleo-saccular hydrops was present in the left ear with Reissners membrane bulging into the horizontal canal. X-ray diffraction and electron probe analysis were used to study the abnormal crystalline deposits in both ears. On the left side the saccular otoconia were composed of calcite, but the utricular macula was covered by a crust of apatite spherulites. More apatite occurred around the maculae and in the scala media. The cupulae were composed of apatite and octacalcium phosphate. On the right side the utricular otoconia were of normal calcite, but there was a deposit of apatite on the macula sacculi. The upper part of the scala media was completely filled by a deposit of apatite and octacalcium phosphate.

Vaterite Otoconia in Two Cases of Otoconial Membrane Dysplasia

Scanning electron microscopy, electron microprobe analysis, and x-ray powder diffraction were used to study temporal bone specimens obtained at autopsy from an infant with Potter syndrome and from a second trimester fetus, which was the product of an elective abortion. The mothers of both the infant and fetus were juvenile-onset rheumatoid arthritis patients who took prostaglandin inhibitors during pregnancy. The infants external ears were low set and the left ear canal was stenotic. The vestibular maculae on the left were covered by aberrant otoconia composed of vaterite. In the right inner ear, otoconia were entirely absent, although the gelatinous otoconial membranes were intact. Only the left saccule and right utricle from the fetus were studied; both contained vaterite crystals similar to those in the infant. In addition, apatite was present in the fetal utricle, apparently lying on the macula beneath the vaterite otoconia.

A calcareous concretion in the posterior semicircular duct of a human labyrinth

Temporal bones were acquired four hours post mortem from a 67-year-old cancer patient. During dissection of the left vestibular labyrinth, a glistening white, spherical concretion was found in the posterior semicircular duct near the ampulla. The object was subsequently studied by light and scanning electron microscopy, x-ray diffraction, and x-ray energy dispersive elemental analysis. It was composed of four concentric layers: an outer zone of tabular vaterite crystals, a colorless intermediate zone of spherulitic octacalcium phosphate (OCP), and a cloudy core with inner and outer zones both composed of OCP. Examination of the vestibular receptor organs revealed severe loss of hair cells on all three cristae. Very few otoconia were present in the utricle, although the gelatinous layer of the otoconial membrane was intact on the macular surface. During the year preceding his death, the patient had received 800 mg of the potentially ototoxic drug cis-platinum. The concretion described in this report was, however, probably connected with age-related degeneration rather than with any effect of the drug.