Biomedical subjects

I Sando

Publications and source records attributed to I Sando.

At least 37 records · Page 2Linked to original sources

PubMed1999

Distribution of psammoma bodies in the internal auditory canal and its extended areas in the human temporal bone.

The internal auditory canal (IAC) and its extended areas of 27 normal human temporal bone specimens were investigated histologically for the distribution of psammoma bodies. A total of 145 +/- 25 (mean +/- SE) psammoma bodies were counted in series of every tenth 30-microm-thick section. Psammoma bodies were observed in the IAC and around the labyrinthine portion of the facial nerve (FN), the geniculate ganglion of the FN, and the posterior ampullary nerve in the singular canal. The number of psammoma bodies increases with age. We believe that psammoma bodies are a normal finding of aging in the IAC. The compression of the FN by psammoma bodies in the labyrinthine portion of the facial canal and the distribution of numerous psammoma bodies surrounding the posterior ampullary nerve in the narrow singular canal raise the questions of the involvement of psammoma bodies in the FN and in vestibular dysfunction and the presence of psammoma bodies in the subarachnoid space.

Adolescent↗

PubMed1998

Histopathological features of a cochlear implant and otogenic meningitis in Mondini dysplasia.

The temporal bones of a 6-year-old boy with a cochlear implant for profound hearing loss associated with Mondini dysplasia were studied histopathologically. Despite having severe Mondini dysplasia, he was able to detect sound with the implant. On histological examination of the temporal bone, he had more than 10000 spiral ganglion cells. Histopathological changes in the inner ear associated with the cochlear implant were minimal. Patients with severe Mondini dysplasia and profound hearing loss may, therefore, benefit from cochlear implantation. In the contralateral ear, the patient had suppurative labyrinthitis and meningitis associated with chronic otitis media. Histopathological evidence of inflammatory necrosis of the round window membrane was consistent with suppurative labyrinthitis secondary to otitis media.

Abnormalities, Multiple↗

PubMed1998

Postnatal development of Eustachian tube: a computer-aided 3-D reconstruction and measurement study.

The postnatal development of the Eustachian tube (ET) and its surrounding structures was investigated by means of computer-aided three-dimensional (3-D) reconstruction methods in 13 normal human temporal bones, obtained from individuals 3 months to 71 years old. The cross-sectional area, width and height of the lumen in most of the cartilaginous portion of the ET were significantly smaller in children than in adults. In particular, there was a marked, age-associated difference in the shape of the lumen in the cartilaginous portion of the ET. In adults, the cross-sectional area of the lumen declined monotonically between a large opening at the pharyngeal orifice and the narrowest portion of the ET (near the border of the cartilaginous and junctional regions). In children, by contrast, the ET lumen was uniformly smaller over the first 80% of its length from the pharyngeal orifice. It is suggested that this immature morphology of the ET lumen may confer increased risk of developing otitis media during childhood.

Adolescent↗

PubMed1998

Three-dimensional reconstruction and measurement study of human eustachian tube structures: a hypothesis of eustachian tube function.

Histologic sections from nine temporal bones with eustachian tubes (ETs) attached were analyzed with a computer-aided three-dimensional reconstruction method to determine the curvature and tilt of the ET and the anatomic relationships between the medial lamina of the ET cartilage, the levator veli palatini muscle (LVPM), and Rosenmüller's fossa. It was found that the ET is convex superomedially and is tilted medially. The LVPM is located inferolateral to the inferior margin of the medial lamina of the anterior ET cartilage. The LVPM is inferior to the medial lamina of the posterior ET cartilage. These findings suggest that the LVPM opens the anterior cartilaginous portion of the ET by rotating the medial lamina with increased dimension of the muscle body when it contracts. Rosenmüller's fossa extends along the ET with rich lymphoid tissues as far as approximately one half the total length of the ET and very close to the skull base.

Adolescent↗

PubMed1997

Postnatal change in angle between the tympanic annulus and surrounding structures. Computer-aided three-dimensional reconstruction study.

Postnatal developmental relationships in human ears were studied by a computer-aided three-dimensional reconstruction and measurement method. We measured the angle, in reference to the horizontal plane, between the tympanic annulus, the oval window, and the internal auditory canal (IAC) in 20 normal temporal bones obtained from individuals between 1 day old and 76 years old. The horizontal plane was defined as the plane sloped 30 degrees infero-anteriorly from the plane of the horizontal canal in each specimen. The plane of the tympanic annulus changed from a nearly horizontal orientation (34.2 degrees from the horizontal plane) in neonates to a more vertical orientation (63.3 degrees from the horizontal plane) in adults. The tympanic annulus and oval window planes remained at the same angle to each other (11.9 degrees +/- 5.1 degrees) throughout postnatal development, as did the plane of the tympanic annulus and the IAC (68.6 degrees +/- 5.3 degrees). These findings have implications for ear surgeons, especially those operating on young children.

Adolescent↗

PubMed1997

Narrowest (isthmus) portion of eustachian tube: a computer-aided three-dimensional reconstruction and measurement study.

Nine normal human temporal bones from persons 16 to 88 years old were studied by computer aided three-dimensional reconstruction and measurement. The length of the eustachian tube (ET) lumen in three portions (from pharyngeal orifice to tympanic orifice: cartilaginous, junctional, and bony) averaged 23.6 +/- 4.3 mm, 3.0 +/- 1.9 mm, and 6.4 +/- 2.6 mm. The narrowest portion of the ET lumen was in the cartilaginous portion in all cases: 20.5 +/- 4.2 mm from the pharyngeal orifice and 3.1 +/- 1.6 mm from the pharyngeal margin of the junctional portion. The cross-sectional area of the narrowest portion was 0.65 +/- 0.2 mm2. The tendon of the tensor veli palatini muscle (TVPM) inserted into the lateral lamina in the narrowest portion of the ET lumen in five of nine cases. These results suggest that contraction of the TVPM opens the narrowest portion of the ET lumen to ventilate the middle ear and that this portion also plays a role in protecting the middle ear.

Adolescent↗

PubMed1997

Immunohistochemistry of lymphocytes and macrophages in human celloidin-embedded temporal bone sections with acute otitis media.

Immunohistochemical analyses were used to investigate the distribution of lymphocytes and macrophages in routine human temporal bone sections obtained from a subject with acute suppurative otitis media. Primary antibodies specific for human CD3 and CD43 (T-lymphocytes), CD20 (B-lymphocytes), CD45 (leukocyte common antigen), and CD68 (macrophages) were used. As a pretreatment, the sections were soaked in antigen retrieval solution (saturated sodium hydroxide-methanol solution in methanol at a ratio of 1:3). A second antigen retrieval procedure (microwave treatment in 1% zinc sulfate) was also employed for identifying CD3-positive cells. Then the avidin-biotin-peroxidase complex technique was performed. Positive reactions to all antibodies but anti-CD68 were observed in the mucosa of the eustachian tube, tympanic cavity, and mastoid air cells. Particularly, cells positive to anti-CD3 or anti-CD43 were making a diffuse invasion upon the lamina propria. CD68-positive cells were scattered only in the effusion of mastoid air cells. These results suggest that the retrospective immunohistochemical study of archival temporal bone sections is a promising approach to investigate the pathogenesis of otitis media.

Acute Disease↗

PubMed1997

Molecular and cellular pathology of Meniere's disease.

The etiopathogenesis of Meniere's disease has remained controversial since the early 1900s. Many investigators have studied the molecular and cellular pathology of the inner ear in patients with this disorder. Three basic pathologic mechanisms have emerged; fibrosis of the endolymphatic sac and vestibular epithelia, altered glycoprotein metabolism, and immune-mediated inner ear disease. This article reviews the current understanding of these three basic pathologic processes.

Endolymphatic Sac↗

PubMed1996

Three-dimensional course of the vestibular aqueduct.

Three-dimensional (3-D) reconstruction methods were employed to study the anatomy of the vestibular aqueducts (VAs) in ten postmortem temporal bone specimens obtained from ten individuals aged 4 months to 70 years at death. After reconstruction, the ten 3-D images of VAs were superimposed on one another and differences evaluated. The VA showed postnatal growth and variations in size and shape. However, the variations in angle at which the VA bends near the isthmus were not correlated with age. Furthermore, study of the superimposed images revealed that the 3-D course of the VA was essentially the same in individuals of all ages, despite its wide variability in size and shape. These results indicate that the basic course of the VA is determined before early infancy although the VA grows thereafter, suggesting that VA anomalies such as "large vestibular aqueduct syndrome" (in which the VA takes an abnormally straight and wide course) may be established prenatally.

Adolescent↗

PubMed1996

Mucosa-associated lymphoid tissue in middle ear and Eustachian tube in children.

The presence of mucosal lymphoid follicles with germinal centers, so called mucosa-associated lymphoid tissue (MALT), in the Eustachian tube (ET) and middle ear (ME) was investigated in 23 human temporal bones containing the entire ET obtained from 23 children, 3 months to 10 years old at death. Greater numbers of MALTs were found in specimens from children with otitis media (OM) than from those without OM. MALT showed a wedge-shaped distribution through the ME and ET: in all 3 specimens that had MALTs in the ME, these tissues were seen throughout the ET; in all 4 specimens with MALTs in the bony portion of the ET, these tissues were present both in the tympanic and pharyngeal portions of the cartilagines ET; all 7 specimens that had MALTs in the tympanic half of the cartilagines ET had MALTs in the pharyngeal portion of the cartilagines ET as well. Furthermore, MALTs were noted in the pharyngeal portion of the ET in more than half of the specimens without OM but in none of the MEs of specimens without OM. These results support the hypothesis that persistent and recurrent inflammation in the nasopharynx spreads through the ET to play a role in the pathogenesis of chronic OM in children.

Cartilage↗

PubMed1996

Developmental changes in folding of the human eustachian tube.

Histologic sections of human temporal bone with Eustachian tube attached were examined to investigate the changes that occur in folding of the Eustachian tube (ET) as it develops postnatally. Study of 45 specimens from individuals aged 3 months to 88 years of death, including 5 cases with chronic otitis media (OM) with perforation and 5 with OM with effusion, showed that the folds in the tube decreased significantly as age increased up to 20 years, after which no significant change with age was found. These results suggest that folding in the ET is important to its function in infants and children. Folding provides a relatively greater surface area for the tube, allowing for a greater abundance of ciliated cells, which would promote clearance of the middle ear through the ET. Greater folding might also support the tube's protective function by keeping the lumen narrow.

Adolescent↗

PubMed1995

Orientation for cochlear implant surgery in cases with round window obstruction: a computer reconstruction study.

In order to improve cochlear implant surgery in patients with obstructed round windows, surgical orientations of the round window and scala tympani relative to the stapes footplate were examined in ten normal temporal bones using a computer-aided, three-dimensional reconstruction and measurement technique. The round window was found to be exactly inferior to the midpoint of the inferior margin of the stapes footplate in most cases. An optimal point on the promontory wall for drilling to reach the bottom of the scala tympani of the basal turn was found to lie approximately 1.5 mm anterolateral or anterolateral inferior to a point 3 mm inferior to the midpoint of the inferior margin of the stapes footplate. A combination of the transmeatal and facial recess approaches made it possible to consistently reach the scala tympani, and demonstrated that this approach was also applicable to patients with obstructed round windows.

Adolescent↗

PubMed1995

Postnatal development of the internal auditory canal studied by computer-aided three-dimensional reconstruction and measurement.

Postnatal development of the internal auditory canal (IAC) was investigated in 20 normal human temporal bones obtained from individuals 1 month to 72 years old. Computer-aided three-dimensional reconstruction and measurement of bones showed that the superior, inferior, anterior, and posterior walls of the IAC lengthen significantly from birth until about 10 years of age, with development mainly attributable to lengthening of the part of the IAC medial to the foramen singulare. The lengths of the part of the IAC lateral to the foramen singulare and of the transverse crest and Bill's bar did not appear to develop postnatally. The IAC diameter increased slightly at the porus for about the first year after birth, but not at the fundus or the middle portion of the canal. This finding was confirmed by studying the shape of the IAC. Postnatal increases in the volume of the IAC followed patterns similar to that of increases in length of studying the shape of the IAC. Postnatal increases in the volume of the IAC followed patterns similar to that of increases in length of the IAC walls. These results show that postnatally the IAC increases significantly in length until about 10 years of age and slightly in diameter until about 1 year of age, especially medial to the foramen singulare. This concentration of growth of the IAC medially implies that its postnatal development is mainly due to growth of the bone around the otic capsule, which has implications for IAC surgery.

Adolescent↗

PubMed1994

Postnatal developmental changes in facial nerve morphology. Computer-aided 3-D reconstruction and measurement.

Accurate measurements of the lengths and angles of the facial nerve were obtained in eight normal human temporal bones of varying ages from 7 days to 76 years. Measurements were made on serial histological sections, using computer-aided three-dimensional (3-D) reconstruction. The most noteworthy of the findings demonstrated that both the mastoid portion of the facial nerve and the segment of the facial nerve between the second genu and the divergence of the chorda tympani nerve lengthened with age. The mastoid segment lengthened more significantly than the latter, indicating the facial canal grows more than the facial nerve in its mastoid portion. This difference in growth rates results in the site of the chorda tympani nerve divergence shifting with age relative to the stylomastoid foramen.

Adolescent↗

PubMed1994

Anatomic relationships between Ostmann's fatty tissue and eustachian tube.

To examine anatomic relationships between Ostmann's fatty tissue (OF) and the eustachian tube (ET), we evaluated serial histologic sections of 32 normal temporal bone-ET specimens and made a quantitative analysis of several measurements (height, width, and volume). We compared results in specimens from individuals in whom the ET was still developing (those 19 years and younger) to results in specimens from individuals with adult ETs (those older than 19). We found that 1) the main body of OF is located at the inferolateral aspect of the ET and 2) postnatally, OF grows in volume, mainly by an increase in height, so that OF maintains the same vertical relationship to the growing ET and does not increase in width. The former finding indicates that OF might exert static pressure on the ET not to open widely. The latter finding indicates that the relatively thicker mass of OF may narrow the ET in those with immature ETs. These results indicate a possible role for OF in ET function, which in turn has been implicated in otitis media with effusion.

Adipose Tissue↗

PubMed1994

Postnatal development of the vestibular aqueduct in relation to the internal auditory canal. Computer-aided three-dimensional reconstruction and measurement study.

To investigate a possible developmental relationship between the internal auditory canal (IAC) and the vestibular aqueduct (VA), we made the following measurements in 10 normal temporal bones from individuals 4 months to 70 years of age at death, using a computer-aided three-dimensional reconstruction and measurement method: the volume of the VA, the length of the IAC, and the distance between the IAC and the external aperture of the VA. The degree of periaqueductal pneumatization was also assessed qualitatively by means of a light microscope. The three parameters increased postnatally in parallel with the development of the periaqueductal air cells, and all pairwise comparisons of these parameters showed a statistically significant correlation. Our results indicate that the IAC and VA develop synchronously and in parallel with the development of the periaqueductal air cells. We believe that an understanding of this relationship will be of help during surgery involving the IAC and VA, and may shed some light on the morphological features of Meniere's disease.

Adolescent↗

PubMed1994

Localization of function in the eustachian tube: a hypothesis.

This communication uses our recent quantitative morphometric studies to develop a hypothesis for localization of ventilatory, clearance, and protective functions in different portions of the eustachian tube (ET). We hypothesize that the ET roof is involved mainly with ventilation and that the ET floor is involved mainly with clearance, whereas both portions are involved with protection of the middle ear. The hypothesis states that 1) the cross-sectional shape of the ET lumen and the attachment of the tensor veli palatini muscle to the tip of the lateral lamina are important for ventilation, 2) the ciliated cells in the ET floor subserve clearance, 3) the richly distributed elastin in the hinge portion of the ET cartilage, Ostmann's fatty tissue, and rich mucosa-associated lymphoid tissue are protective, 4) the well-developed ET cartilage lateral lamina is important for both ventilation and protection, and 5) the rich mucosal folding, goblet cells, and glands subserve both clearance and protection. Finally, the utility of the hypothesis for elucidating anatomic factors in otitis media is discussed.

Eustachian Tube↗

PubMed1993

Mucosal folds of eustachian tube in young children.

Differences in the extent of mucosal folding in the superior versus the inferior half of the human Eustachian tube (ET) were studied in young children by measuring the length of the mucosal margin and counting the number of mucosal folds, as they appeared in histological cross-sections, in the pharyngeal, midcartilaginous, isthmus, and osseous portions of each half of the ET in 12 normal ET/temporal bone specimens from 12 individuals aged 1 day to 2 years. The mucosal margin of the ET was significantly longer in the inferior half than in the superior half in the pharyngeal, midcartilaginous, and isthmus portions (paired t-test, pharyngeal portion: t[11] = 3.71, p < 0.01; midcartilaginous portion: t[11] = 4.52, p < 0.01; isthmus portion: t[11] = 3.40, p < 0.01). However, there was no significant difference between in the inferior half and in the superior half at the osseous portion. Also there were significantly more mucosal folds in the inferior half than in the superior half in all four portions (paired t-test, pharyngeal portion: t[11] = 3.46, p < 0.01; midcartilaginous portion: t[11] = 7.40, p < 0.01; isthmus portion: t[11] = 5.03, p < 0.01; osseous portion: t[11] = 4.49, p < 0.01). These results indicate that the surface area of the mucosa in the inferior half of the ET is larger than that of the superior half.(ABSTRACT TRUNCATED AT 250 WORDS)

Child↗