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Biomedical subjects

B W Jafek

Publications and source records attributed to B W Jafek.

At least 19 recordsLinked to original sources
PubMed1992

Ultrastructural histopathology of human olfactory dysfunction.

This paper presents electron-microscopic observations on biopsies of the olfactory mucosae of several classes of patients with smell disorders: 1) patients with loss of smell function following head injury (post-traumatic anosmics or hyposmics); 2) patients with loss of smell function following severe head colds and/or sinus infections (post-viral olfactory dysfunction, or PVOD); and 3) patients that have lacked smell function since birth (congenital anosmics). Of these, the traumatic anosmics' olfactory epithelia were quite disorganized; the orderly arrangement of supporting cells, ciliated olfactory receptor neurons, microvillar cells, and basal cells was disrupted. Although many somata of ciliated olfactory receptors were present, few of their dendrites reached the epithelial surface. The few olfactory vesicles present usually lacked olfactory cilia. The post-viral anosmics, too, had a greatly reduced number of intact ciliated olfactory receptor neurons, and most of those present were aciliate. The post-viral hyposmics had a larger population of intact, ciliated olfactory receptor cells. In the seven cases of congenital anosmia studied, no biopsies of olfactory epithelium were obtained, indicating the olfactory epithelium is either absent--or greatly reduced in area--in these individuals.

Biopsy↗
PubMed1992

Ultrastructural neurobiology of the olfactory mucosa of the brown trout, Salmo trutta.

This paper describes four investigations of the olfactory mucosa of the brown trout: 1) the ultrastructure of the olfactory mucosa as revealed by scanning (SEM), conventional transmission (TEM), and high voltage (HVEM) electron microscopy; 2) light and electron-microscopic investigations of retrograde transport of the tracer macromolecule horseradish peroxidase (HRP) when applied to the cut olfactory nerve; 3) SEM and TEM investigations of the effects of olfactory nerve transection on cell populations within the olfactory epithelium; and 4) ultrastructural investigations of reversible degeneration of olfactory receptors caused by elevated copper concentrations. The trout olfactory epithelium contains five cell types: ciliated epithelial cells, ciliated olfactory receptor cells, microvillar olfactory receptor cells, supporting cells, and basal cells. The ciliated and microvillar olfactory receptor cells and a small number of basal cells are backfilled by HRP when the tracer is applied to the cut olfactory nerve. When the olfactory nerve is cut, both ciliated and microvillar olfactory receptor cells degenerate within 2 days and are morphologically intact again within 8 days. When wild trout are taken from their native stream and placed in tanks with elevated copper concentrations, ciliated and microvillar cells degenerate. Replacement of these trout into their stream of origin is followed by morphologic restoration of both types of olfactory receptor cells. Ciliated and microvillar receptor cells are primary sensory bipolar neurons whose dendrites make contact with the environment; their axons travel directly to the brain. Consequently, substances can be transported directly from the environment into the brain via these "naked neurons." Since fish cannot escape from the water in which they swim, and since that water may occasionally contain brain-toxic substances, the ability to close off--and later reopen--this anatomic gateway to the brain would confer a tremendous selective advantage upon animals that evolved the "brain-sparing" capacity to do so. Consequently, the unique regenerative powers of vertebrate olfactory receptor neurons may have their evolutionary origin in fishes.

Animals↗
PubMed1992

Calbindin-like immunoreactivity in two peripheral chemosensory tissues of the rat: taste buds and the vomeronasal organ.

In the rat, calbindin-like immunoreactivity was observed at both the light and electron microscopic levels within the chemoreceptor neurons of the vomeronasal organ (VNO) and both intragemmal cells and associated nerve fibers of the circumvallate taste buds. All VNO neurons were immunoreactive. Only a subset of intragemmal taste cells was immunoreactive; associated immunoreactive nerve fibers were apposed to both labeled and unlabeled cells but no synaptic contacts were observed.

Animals↗
PubMed1991

The vomeronasal (Jacobson's) organ in man: ultrastructure and frequency of occurrence.

These investigations address three major questions: (1) What is the frequency of occurrence of the vomeronasal (Jacobson's) organ (VNO) in man? (2) what is the ultrastructure of the human VNO? and (3) does the VNO contain sensory receptor cells? Macroscopic and microscopic intranasal clinical examinations of over 200 persons revealed paired bilateral vomeronasal pits on the anterior 1/3 of the nasal septum in all cases. Biopsies of the vomeronasal pits and surrounding tissues were examined by light and electron microscopy. These studies showed that the vomeronasal pit leads to a closed tube, 2-8 mm long, lined by a unique pseudostratified columnar epithelium unlike any other in the human body. The anterior end of the tube is lined by tall, columnar cells with a sparse population of short microvilli. The posterior end of the VNO is lined by an epithelium that contains three morphologically distinct cell types: (1) basal cells; (2) "dark cells--tall, slender cells with heterochromatic nuclei and electron-dense cytoplasm that often contain mucigen-like granules; and (3) "light" cells--large, clear cells, extending from the basement membrane to the organ's lumen. Each "light" cell has a round, euchromatic nucleus and a clear cytoplasm that often contains many Golgi stacks and membrane-limited vesicles filled with material of modest electron density. The cell apex is tipped by a few short microvilli. Whether these cells subserve any sensory function awaits further investigation.

Adult↗
PubMed1991

Intrinsic vasculature of the labyrinthine segment of the facial nerve--implications for site of lesion in Bell's palsy.

Recent studies of the intrinsic vasculature of the cat facial nerve have demonstrated relatively poor blood supply to the labyrinthine segment. In this study, the intrinsic vasculature of the human facial nerve was systematically evaluated in 25 temporal bones and three fresh cadaver nerves. Cross-sectional vessel counts were obtained for the labyrinthine, tympanic, and mastoid segments. Capillary densities for each segment were derived from these data. The labyrinthine segment of the human facial nerve, like that in the cat, contains fewer and smaller intrinsic blood vessels than do the mastoid and tympanic segments. This may indicate that the labyrinthine segment of the facial nerve may be more vulnerable to ischemic damage. In conjunction with the previously demonstrated narrowness of the labyrinthine fallopian canal, these findings support the contention that the labyrinthine segment is a likely site of lesion in Bell's palsy.

Ear, Inner↗
PubMed1991

The intraoperative management of the thyroid gland during laryngectomy.

The standard of care of laryngeal cancer surgery is wide field excision of the larynx combined with ipsilateral thyroid lobectomy. A retrospective review of 247 laryngectomies performed between 1979 and 1989 was undertaken to determine specific intraoperative indications for thyroid gland removal. The incidence of thyroid disease in our patients with laryngeal cancer was compared to the normal population. Eight percent of thyroid specimens removed during laryngeal cancer surgery demonstrated invasion by squamous cell carcinoma. All patients having thyroid invasion had T3 or T4 laryngeal lesions that were stage IV at the time of surgery. All these lesions were found to have transglottic growth and laryngeal cartilage invasion by the pathologist. All of these patients also had abnormal thyroid glands intraoperatively and laryngeal cartilage destruction that was evident intraoperatively. Total thyroidectomy with bilateral paratracheal and pretracheal lymph node dissection is indicated when squamous cell carcinoma of the larynx involves the thyroid gland. Prophylactic ipsilateral thyroid lobectomy and isthmusectomy is warranted for large laryngeal cancers (T3, T4) that involve the anterior commissure, the subglottic area, or extend transglottically. Routine thyroid gland removal is not indicated for the majority of laryngeal cancers that do not meet the aforementioned criteria. Finally, abnormal thyroid histopathology was diagnosed in 37% of the surgical thyroid gland specimens removed during laryngectomy.

Adenocarcinoma↗
PubMed1979

Surgical management of the hypodynamic palate.

The most successful surgical correction of velopharyngeal insufficiency (VPI) has been achieved in those patients in whom residual dynamic function of the soft palate/nasopharyngeal sphincter mechanism exists. In spite of the obvious need for rehabilitation, surgical reconstruction has often been advised against in those cases where the palate was hypodynamic or adynamic. We have developed a surgical procedure for these patients by utilizing a modification of Hogan's lateral port control pharyngeal flap method. We present the surgical considerations along with the initial application and results in four patients with hypodynamic palates of differing origins. We think that this technique extends surgical correction of VPI to the previously neglected group of patients in whom this condition is the result of a hypodynamic palate.

Adolescent↗
PubMed1979

Hearing loss in Down's syndrome. A treatable handicap more common than generally recognized.

Significant hearing loss was found in about two-thirds of a series of 107 individuals with Down's syndrome. Hearing loss of that degree causes retardation of speech, language and intellectual development in normal children. Down's children are presumably affected even more by this sensory deprivation and without correction are prevented from reaching their full potential.

Adolescent↗
PubMed1979

Transbronchial drainage of pulmonary abscesses with the flexible fiberoptic bronchoscope.

Flexible fiberoptic bronchoscopy with multiplanar fluoroscopic control is shown to be effective in the transbronchial drainage of pulmonary abscesses. A new technique which permits the intracavitary placement of brush forceps and fine arterial catheters is described. This has facilitated the rapid defervescence of fever and established immediate endobronchial drainage. Seventy percent of patients had complete radiographic closure of their abscess cavities at three months. Clinical findings are presented and the role of aspiration in pathogenesis of pulmonary abscess is stressed.

Adult↗
PubMed1979

Bronchial adenoma: a malignant misnomer.

Bronchial adenomas are a histologically and clinically diverse group of respiratory tract neoplasms arising from mucous glands and ducts of the tracheobronchial tree. They represent 1% of pulmonary malignancies. The traditional concept of a single, histologically benign form is challenged and the malignant potential of these tumors is stressed. Three main cell types with their characteristic histopathologic and clinical features are discussed: carcinoid, adenoid cystic carcinoma, and mucoepidermoid carcinoma. A case of bronchial carcinoid with hepatic metastases is reported, emphasizing the malignant potential of this controversial group of tumors. The appropriate diagnostic evaluation is outlined and aggressive surgical management is stressed. Chemotherapy and radiation therapy which are reserved mainly for palliation do not add to overall five year survival rates.

Adenocarcinoma↗
PubMed1978

The anatomy of the nose. External support.

The anatomy of the nose is poorly defined, even in standard anatomical texts. Wide disagreement exists regarding the interdigitation of the supporting cartilages, the articulation of these cartilages with the nasal bones, and the contribution of each of these cartilages to the support of the external nose. An understanding of this nasal anatomy is essential to the facial plastic surgeon. The authors describe the fundamental anatomical structure of the adult nose based on gross and microscopical observations and serial sections in 31 cadaveric noses. Tables of cartilage measurements and variation, plus appropriate drawings define the anatomy encountered. Structural variations are common and can be predicted by external appearance in selected cases. To discuss relationships of importance in the surgical alteration of the nose in rhinoplasty, anatomical findings are compared to descriptions in the surgical and anatomical literature. Preservation of essential support and physiological function is stressed.

Adult↗
PubMed1978

Middle ear effusions in neonates.

Suppurative middle ear effusions (MEE) have been shown to occur commonly in neonates. In spite of this, otoscopy is not routinely performed on septic infants in the neonatal intensive care unit (ICU). This is clinically significant since unrecognized suppurative MEE may act as a focus for dissemination of bacteria into the circulation and/or central nervous system (CNS). We have completed a prospective study in an attempt to define the prevalence, bacteriology, and response to therapy of MEE in neonates. To facilitate this, the normal micro-otsocopic appearance of the newborn TM was established by systematically examining 50 normal infants under 24 hours old. MEE was present in 30% of 125 consecutively examined infants in the neonatal ICU. Bacteriologic data are drawn from tympanocentesis performed on 34 neonates. Nasotracheal intubation of longer than seven days is highly associated with suppurative MEE. Suppurative MEE in the neonatal ICU is often refactory to treatment and may require prolonged therapy and repeated tympanocentesis.

Animals↗
PubMed1977

Spontaneous subcutaneous emphysema of the neck and mediastinum.

An unusual case of spontaneous subcutaneous emphysema and pneumomediastinum presumably caused by a laryngeal or hypopharyngeal tear during excessive phonation is presented. The patient was treated conservatively after a careful search for any causative factors. Observation, with parenteral ailimentation, intravenous antibiotics, and voice rest, is advocated for most cases. Tracheostomy and open repair or mediastinotomy are reserved for the unusually severe or unresolving case.

Adolescent↗
PubMed1977

Olfaction.

Explore the source record for details and available documents.

Humans↗