Biomedical subjects

H T Bui

Publications and source records attributed to H T Bui.

6 recordsLinked to original sources

PubMed1996

Tympanic membrane reconstruction using formaldehyde-formed autogenous temporalis fascia: twenty years' experience.

This study describes 20 years' experience with autogenous temporalis fascia that is formed and shaped by formaldehyde cross-linking with special Fasciaform (Hear America, Palo Alto, Calif.) molds in the repair of large tympanic membrane perforations. One hundred twenty operations in 113 patients were performed between 1973 and 1993 to close large perforations in patients with intact ossicular chains. All perforations were successfully closed by this technique. Audiometric studies indicated that the postoperative air-borne gap was closed to within 0 to 10 dB in 63% and to within 0 to 20 dB in 97%. One patient had a 15-dB sensorineural hearing impairment. Graft lateralization requiring revision occurred in three patients, two of whom had previous unsuccessful tympanoplasties. Comparisons of adult vs. pediatric groups and primary vs. revision groups were made. The technique ensures the removal of any ectopic epithelium on the medial surface of the tympanic membrane remnant and provides for easy graft placement and stability during healing without the use of middle ear Gelfoam (Upjohn Co., Kalamazoo, Mich.). The formaldehyde-formed fascia graft or Fasciaform graft technique provides an effective method of closing large perforations with excellent functional results and minimal complications.

Adolescent↗

PubMed1989

Histologic and statistical studies on hyalin bodies in the human endolymphatic sac.

Hyalin bodies are amorphous, eosinophilic masses that protrude from the subepithelial connective tissue into the lumen of the endolymphatic sac. In this study, hyalin bodies were analyzed in two groups of temporal bones: normal bones and bones with cochlear otosclerosis. The results revealed that bones with cochlear otosclerosis had significantly more and larger hyalin bodies that did normal bones. In addition, the hyalin bodies in cochlear otosclerosis were denser and associated with more edema and loose connective tissue in the surrounding areas. Foamy macrophages, concentric calcific structures, and bony ingrowth were frequent features of the hyalin bodies in the cochlear otosclerosis. Our current hypothesis is that these hyalin bodies are repository of membranous cellular debris phagocytized by the macrophages. If this is true, the hyalin bodies may further support the proposed resorptive and phagocytic functions of the endolymphatic sac and the enzymatic concept in cochlear otosclerosis.

Adolescent↗

PubMed1989

Electron microscopy of hyalin bodies in the human intraosseous endolymphatic sac.

Hyalin bodies are amorphous, eosinophilic masses protruding from the subepithelial connective tissue into the lumen of the intraosseous endolymphatic sac (ES). We studied hyalin bodies at the electron microscopic level. Celloidin- embedded temporal bone sections known to have hyalin bodies were re-embedded into plastic and cut into thin sections appropriate for electron microscopy. The results revealed that the hyalin bodies are composed predominantly of thick bundles of collagenous fibers arranged in various directions. Fibroblasts and disintegrated macrophages were occasionally observed among the collagen fibers. Concentric calcific structures found within the hyalin bodies were composed of multiple smaller, concentric, lamellar calcifications. The results of this study support the hypothesis that the hyalin bodies are a repository of membranous cellular debris phagocytized by the macrophages.

Calcinosis↗

PubMed1989

An immunohistochemical study of the endolymphatic sac in patients with acoustic tumors.

Intraosseous endolymphatic sacs obtained from patients with acoustic neuromas who had undergone total labyrinthectomy during tumor removal were examined for the presence of T helper/inducer and T suppressor/cytotoxic lymphocytes, B lymphocytes, plasma cells, and macrophages. Immunoperoxidase staining of cryostat sections revealed the presence of T helper/inducer lymphocytes, T suppressor/cytotoxic lymphocytes, and macrophages. The number of B lymphocytes and plasma cells was much smaller than the number of T lymphocytes. The number of T suppressor/cytotoxic lymphocytes was higher than the number of T helper/inducer lymphocytes. This study supports the notion of local immune responsiveness in the human inner ear. This is the first immunohistochemical study to analyze lymphocyte subpopulations; specifically, to provide insight into T-cell function in the endolymphatic sac.

Antigens, Differentiation↗

PubMed1982

[Surgical procedure in complicated mitral stenosis].

The experience with the surgical treatment of complicated forms of mitral stenosis in 110 patients with the III and IV classes of the disease according to the classification of the New York Heart Association was analyzed. Closed mitral commissurotomy was performed in 36 patients, opened commissurotomy--in 33 patients, prosthetics of the mitral valve was made in 41 patients. Closed mitral commissurotomy is believed to be the simplest method of correction of the duct in mild calcinosis and deformity of the mitral valve, and fixed thrombosis of the left auricle. Opened mitral commissurotomy was justified in case of thrombosis of the left auricle and mild calcinosis and deformity of the valve. Substitution of the valve is indicated in cases of massive calcinosis and rough deformity of the valve and subvalvular structures when valve-preserving operations are impossible.

Adult↗

PubMedDate not supplied

Human endolymphatic sac: morphologic evidence of immunologic function.

The ultrastructure of ten normal human endolymphatic sacs (ES), fixed immediately after death and obtained at autopsy, was observed by transmission electron microscopy. The roles of the epithelium, subepithelial space, vasculature, and ES leukocytes were morphologically studied to evaluate possible immunologic functions of the human ES. In addition, five intraosseous ES biopsies from patients undergoing translabyrinthine acoustic neuroma resection were studied using the immunoperoxidase technique to identify specific leukocyte subpopulations. Evidence of phagocytic activity included the presence of phagocytic epithelial cells, monocytes, macrophages, and polymorphonuclear leukocytes. Immune surveillance was suggested by intraepithelial and subepithelial T-lymphocytes, numerous fenestrated blood vessels, and the presence of a homogeneously staining substance within the lumina of ES epithelial tubules. No B-lymphocytes were found. The findings support the existence of a local immune system of the normal human inner ear.

Adult↗