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Biomedical subjects

W F Marovitz

Publications and source records attributed to W F Marovitz.

15 recordsLinked to original sources
PubMed1978

Detection of H2-b and Thy-1.2 surface antigens on the differentiating murine otocyst using Nomarski optics.

The 12th postcoital day otocyst appears as a hollow cellular ball of pseudostratified columnar epithelium that has entered into its inital stages of differentiation and organogenesis. H-2b antigen was demonstrated on the ectodermally derived epithelial cells of the otocysts and on the mesodermally derived cells of the surrounding mesenchyme. Thy-1.2 antigen was detected in the mesenchymal cells, but not on the epithelial cells of the otocyst. The use of Nomarski optics as a new method for detecting cell surface staining that would otherwise be undetected by bright field optics was demonstrated.

Animals↗
PubMed1978

Tympanic neurectomy and chorda tympanectomy for the control of drooling.

Seventeen patients suffered from drooling that either occurred as a sequelae of extensive head and neck cancer resections or was due to neurological disorders. In these patients, a tympanic neurectomy and/or chorda tympanectomy was performed in an attempt to eliminate the drooling. The conditions in five of 12 (41%) patients with head and neck cancer were improved following such surgery. Two of four children with cerebral palsy initially had a good result. However, the long-term follow-up of the patients demonstrated that the drooling recurred. An additional patient suffering from bulbar weakness and drooling owing to a cerevrobascular accident had less problems with salivary secretions. The results were relatively disappointing; there are several possible explanations for this.

Adolescent↗
PubMed1978

The evaluation of middle ear meningiomas using computerized axial tomography.

Meningiomas localized within the middle ear and mastoid which have no intracranial component are rare tumors. Three patients with meningiomas which were thought to involve only the middle ear were treated surgically, were followed for two to six years and were thought to have been cured. However, when computerized axial tomography became clinically available, these patients were examined using this radiographic technique. Unexpectedly, all three patients were found to have a large intracranial meningiomatous extension. A review of the literature reveals only 13 primary meningiomas; these case reports are summarized. It was noted that definitive tests for an intracranial extension of the meningioma were performed in only 2 of the 13 cases. Therefore, in view of our recent clinical experience, it is recommended that a patient presenting with a middle ear meningioma should have a computerized axial tomographic examination of the head to detect the possible presence of a clinical silent intracranial involvement.

Adolescent↗
PubMed1977

Comparative histological study of mini pig skin after chemical peel and dermabrasion.

Although individual studies of the histological changes after chemical peel and dermabrasion have been reported, there has not been a comparative study of these modalities in the same animal mode. Using the mini pig, whose skin most closely resembles human skin, a study was performed of histological changes 24 hours to 16 weeks after dermabrasion and chemical peel. A considerable increase in thickness of the new collagen layer was noted after chemical peel in contrast to that seen in skin after dermabrasion. The skin surface after chemical peel appeared smoother after 16 weeks, suggesting that chemical peel may be a more effective modality for treatment of the fine wrinkles of aging skin.

Animals↗
PubMed1976

The role of cellular degeneration in the normal development of (rat) otocyst.

From day 12 to 16 of gestation a highly circumscribed zone of cellular degeneration has been observed in the otocyst of more than 50 normal rats. This zone appears to be produced by selective or programmed cell death, and results in the elimination of unneeded cellular elements. That cells in this zone are also selectively destroying subcellular organelles as a first step in specialization is also discussed. Programmed cellular death has long been known in other systems and is often an obligatory companion to cellular specialization. The ear now joins the long list of organs which demonstrate this phenomenon.

Animals↗
PubMedDate not supplied

Single mitotic center for rodent cochlear duct.

The pattern of terminal mitosis in mouse otocyst observed by Ruben led him to postulate the existence of a growth zone at the junction of saccular and cochlear primordia. With the use of colchicine, an antimitotic drug, a localized zone of mitotic activity has been demonstrated at this predicted site.

Animals↗
PubMedDate not supplied

An improved method for processing early rat otocysts for the electron microscope.

Various methods of dissection, fixation, osmication, sectioning and staining were tested in order to develop an acceptable technique for preparing 9, 10, 11, and 12-day-old rat otocysts for electron microscopic study. The general problems associated with embryonic tissue-difficult handling, high water content and poor stainability are discussed, and concrete methods of preparation which significantly decrease these difficulties are proposed. The specific fixation and sectioning requirements of rat otocyst are also described in the elaboration of a method which will be used in subsequent studies of the organogenesis of rodent ear.

Animals↗
PubMedDate not supplied

Ultrastructural development of the early rat otocyst.

The ultrastructural development and differentiation of cells forming the rat otocyst were studied from the 9th to the 13th postcoital day (PCD). The earliest stage investigated was a simple ovoid structure with a connecting stalk to the surface ectoderm. A process of programmed cellular death involving surface ectoderm, connecting stalk, and lateral otocyst wall rapidly detached the otocyst. The cells forming the otocyst were roughly columnar, the organelles were polarized; mitochondria occurred in greatest number basally and in the supranuclear area; Golgi membranes when present were supranuclear. Luminal cells had many microvilli and cilia of various lengths were detected. The shorter, incompletely formed cilia terminated in small knob-like blebs. With each day the otocysts became more complicated and the endolymphatic duct made its appearance as an evagination of the otocyst. Many more cells were seen to have cilia in various stages of development, and by the 12th PCD possibly each cell of the main otocystic cavity had a kinocilium. Growth of the otocyst due to mitosis occurred to a great extent from a single ventromedial center. Cells in mitosis, although seen at other sites, were in greatest abundance in this area; cellular involution apparently was a related function. Together the process of over-production and programmed cellular involution of supranumerary cells not lost to other causes (e.g., environmental) may represent an evolutionary advantage.

Animals↗
PubMedDate not supplied

Scanning electron microscopic appearance of rat otocyst of the twelfth postcoital day: elaboration of a method.

A method for removal, fixation, microdissection, and drying of early rat otocyst for examination by the scanning electron microscope is elaborated. Tissues were dissected, fixed as for conventional transmission electron microscopy and dried by critical point evaporation using amylacetate as the transitional fluid and carbon dioxide as the pressure head. Otocysts were either dissected at the time of initial fixation, or subsequent to drying. The otocyst of the 12th postcoital day was used as a model system in this preliminary report. Critical point drying retained the overall configuration and the fine ultrastructural detail of the otocyst. The interior otocystic surface was visualized and cilia bearing cells of the luminal surface were identified. Most if not all of these cells had a comspicuous, but short kinocillum which terminated in an ovoid bulb. The scanning electron microscopic appearance was correlated to the transmission electron microscopic image seen in the second paper in this Supplement.

Animals↗
PubMedDate not supplied

Intercellular junctions in the differentiating rat otocyst.

Intercellular junctions between cells of the rat otocyst on the 12th day of gestation were studied using lanthanum tracer and freeze-fracture techniques. At the luminal surface, the intercellular space is closed by a series of tight junctions. Gap junctions are also present between cells both within and below the luminal junctional complex. The presence of tight and gap junctions at this early stage in the differentiating otocyst is probably essential for the development of a normally functioning adult ear.

Animals↗
PubMedDate not supplied

Evaluation of tympanic neurectomy and chorda tympanectomy surgery.

Thirty patients were treated by tympanic neurectomy, chorda tympanectomy, or both for a variety of conditions. Out of six patients with gustatory sweating treated by tympanic neurectomy, two patients were relieved of symptoms, two were improved, and two remained unchanged. In five cases of benign recurrent painful parotid swelling, only two patients noted improvement in symptoms. Seventeen patients suffered from drooling. Out of 12 postresection head and neck patients, 5 (41%) were improved following such surgery. Two of four cerebral palsy children initially had a good result. However, the long term follow-up of the patients demonstrated that the drooling recurred. An additional patient who suffered from drooling caused by bulbar weakness following a cerebrovascular accident had fewer problems with salivary secretions postoperatively. The pertinent anatomy and pathophysiology is outlined. The possible reasons for the relatively disappointing results achieved are discussed.

Adult↗