Anita Newman

Histopathology of congenital subglottic stenosis

Three patients with congenital subglottic stenosis are presented and whole organ serial‐section studies of their larynges are discussed. A superiorly displaced first tracheal ring is observed to form a cartilaginous subglottic stenosis in one. This “trapped first ring” is demonstrated in horizontal, sagittal and coronal planes. Subglottic stenosis is a clinical diagnosis which describes multifarious histopathological forms of narrowing within the subglottic larynx.

Osteosarcoma and chondrosarcoma of the head and neck

Osteosarcomas and chondrosarcomas are rare malignant neoplasms in the head and neck. Eighteen cases seen at the UCLA Center for the Health Sciences are reviewed. Osteosarcomas of the maxilla tended to occur a decade later than those of the mandible or cranial bones. Several followed prior irradiation for retinoblastoma. Complete excision offers the only realistic chance for cure. Adjuvant therapy has little to offer these patients at this time.

Projections of the individual vestibular end-organs in the brain stem of the squirrel monkey

The central nervous system (CNS) projections of primary afferent neurons from individual vestibular receptors were studied using horseradish peroxidase (HRP) or biocytin labeling in 14 ears from 7 adult squirrel monkeys using the technique developed in the chinchilla (Lee et al., 1989, 1992). The specificity of labeling was verified by examining the location of the labeled fibers and cell bodies in the vestibular nerve and Scarpas ganglion. Labeled fibers and cells were restricted to nerves and areas belonging to groups of cells in either the superior or the inferior ganglion of the vestibular nerve. In the vestibular nerve root, labeled primary afferent fibers also exhibited a receptor-dependent segregation at the entrance to the medulla. Fibers from the HSC and the SSC were found rostrally and those from the PSC and the SAC were found in the caudal area. The UTR fibers were situated intermediate between these two groups of fibers. (A bundle of fibers, probably vestibular efferents, was identified immediately rostrally and ventromedially to the UTR fibers.) The primary afferent fibers bifurcated into secondary ascending and descending fibers at the lateral border of the vestibular nuclei, forming a longitudinal rostrocaudal vestibular tract. The secondary fibers from individual end-organs occupied specific locations in the tract: the UTR fibers were dorsal to the SSC and the HSC fibers, PSC fibers were found most medially, and the SAC fibers occupied the lateralmost area. The secondary UTR fibers overlapped considerably with those of the SSC and the HSC. The orderly receptor-dependent segregation of fibers was more prominent in the descending tracts than in the ascending tracts. In the vestibular nuclei complex the location of the tertiary branches of various end-organs exhibited considerable overlap within the major vestibular nuclei (SN, superior nucleus; LN, lateral nucleus; MN, medial nucleus; DN, descending nucleus). There were still differences, however, in the projection pattern. Fibers from the SAC ran primarily in the lateral area, fibers from the SSC and the UTR were found ventromedially to the SAC fibers, and the HSC projected slightly medially to the fibers from the SSC. The PSC fibers projected most medially. The UTR and SAC sent numerous fibers to the cerebellum. Fibers from the semicircular canals projected through the rostrodorsal region of the SN and presumably also projected to the cerebellum. The precise termination of fibers was evaluated by studying the location of labeled boutons, which were identified in all major vestibular nuclei. Labeled boutons from all the receptors were in the rostral and central areas of the SN, and in the MN mainly in the rostral two-thirds. In the LN, boutons from all the receptors were in the rostroventral part, most of which were from the UTR and SAC. No labeled boutons were in the caudodorsal part of this nucleus. Labeled boutons in the DN primarily surrounded the descending tract fibers and were particularly prominent medially. In specimens in which superior vestibular nerve receptor organs were scratched vestibular efferent fibers were also labeled. These fibers traveled in the most ventral part of the vestibular nerve root and projected in the ventral aspect of the LN to labeled soma in the ipsilateral and contralateral brain stem. Specificity the in projection patterns of efferent fibers from different end-organs could not be ascertained.

Orbital Lesions in the Blue Rubber Bleb Nevus Syndrome

PURPOSE To identify ophthalmologic manifestations of the blue rubber bleb nevus syndrome, a rare cutaneovisceral hemangiomatosis. METHODS The authors report two patients with a diagnosis of blue rubber bleb nevus syndrome with orbital hemangiomas. RESULTS In one patient, the orbital lesion presented with signs and symptoms similar to an orbital varix and in the other with lid ecchymosis from an eyelid lesion. CONCLUSION Patients with the blue rubber bleb nevus syndrome may have vascular orbital lesions associated with intermittent proptosis. Ophthalmologists should be familiar with the syndrome and its life-threatening complication of gastrointestinal hemorrhage.

Ameloblastoma of the mandible with cervical lymph node metastasis

Ameloblastoma is an uncommon, slowgrowing, odontogenic epithelial tumor. This lesion is thought to originate from precursor cells of the tooth follicle, and invades the spongy trabecular matrix of the mandible and maxilla. It extends with finger-like projections, making complete resection difficult with curettage or conservative local excision1 Although histologically benign, the tumor may invade local structures; metastases to regional nodes or distant sites such as lung, liver, and skin, although reported, are rare. Because of its invasive characteristics, this tumor is capable of causing significant disfigurement and morbidity. On rare occasions individuals succumb to this disease, more often when it occurs in the maxilla. There have been nine reported cases of ameloblastoma with cervical lymph node metastasis.2*3 This case serves to emphasize the potentially recurrent, aggressive nature of this tumor, despite seemingly adequate resection.

Midline nasal destruction in cocaine abusers.

Idiopathic midline destructive disease (IMDD) is a diagnosis of exclusion in patients who manifest midline nasal necrosis with no specific etiology such as infection, tumor, or Wegeners granulomatosis. Recently, a group of cocaine abusers has been identified that manifests a syndrome that mimics IMDD, but is less fulminant in its course. To better define the natural history of this syndrome, we reviewed the medical records, radio-graphs, and pathologic material from five such patients treated at the University of California, Los Angeles. Other causes of midline nasal destruction were excluded in each patient on the basis of histopathology, cultures, and laboratory tests. Biopsy material, available in four patients, demonstrated inflammation and necrosis without vasculitis. Treatment was conservative in four of the five patients, using antibiotics, local care, debridement, and cessation of cocaine use. During the follow-up period, progressive disease developed in one of the five patients, requiring radiation and steroid therapy. We conclude that the treatment of midline nasal destruction in cocaine abusers should initially be conservative, once other etiologies have been systematically excluded.

Regeneration of the eighth cranial nerve. I. anatomic verification in the bullfrog

The regenerative capacity of the eighth cranial nerve of the bullfrog, Rana catesbeiana, was investigated. The nerve was sectioned between the ganglion and the brain stem in 16 experimental animals. Horseradish peroxidase was extracellularly injected distal to the site of the nerve section five or more weeks postoperatively. Labeled fibers were identified histologically and their central nervous system projections studied. The findings were as follows: 1. The eighth cranial nerve of the bullfrog regenerated after preganglionic axotomy. 2. Fibers of all sizes regenerated. The regenerated fibers in the nerve were disorderly at the site of nerve section. Most fibers entered the brain stem and formed a vestibuloauditory tract, although some “escaped” and coursed along the brain stem. 3. The regenerated vestibuloauditory tract was situated more laterally than normal, with thick and thin fibers intermixed. 4. Regenerated tertiary fibers were long and tortuous and had unusual trajectories. 5. All vestibuloauditory nuclei received thick and thin afferent fibers.

Expression of brain-derived neurotrophic factor and its receptor mRNA in the vestibuloauditory system of the bullfrog

Brain-derived neurotrophic factor (BDNF) is a neurotrophin which has been suggested to play a crucial role in the development and maintenance of the inner ear. In the present study, we investigated the expression of mRNAs of BDNF and its high-affinity receptor trkB in the vestibuloauditory system of the adult bullfrog. In situ hybridization was performed using riboprobes transcribed from Xenopus BDNF and trkB cDNA clones. BDNF mRNA was expressed in the sensory epithelia of the ampullary cristae, utricular and saccular maculae, lagena, and amphibian and basilar papillae. Strong hybridization for BDNF mRNA was also found in neuron somata of the vestibuloauditory nuclear complex. trkB mRNA was detected in the sensory epithelia of all vestibular and auditory endorgans. High levels of both BDNF and trkB mRNAs were found in vestibuloauditory ganglion cells. These results support the hypothesis that BDNF participates in the maintenance of vestibuloauditory neurons and may be important for the trophic regulation of vestibular and auditory sensory epithelia in this animal model.

Primary vestibular projections in the chinchilla.

SummaryThe central projections of fibers from the vestibular nerve were studied in 19 chinchillas after horseradish peroxidase labelling. In addition, the limits of the vestibular nuclei and the anatomical characteristics of their neurons were also studied. All five vestibular nuclei received primary afferents, but there were extensive areas of them that received very little or no projections at all, such as the rostral part of the superior vestibular nucleus, the dorsocaudal part of the lateral vestibular nucleus, the caudal half of the medial vestibular nucleus and the caudalmost aspect of the dorsal vestibular nucleus.

Regeneration of the eighth cranial nerve II. Physiologic verification in the bullfrog

Two experiments were performed to document the functional capacity of the regenerated eighth cranial nerve. In experiment 1, the eighth cranial nerve was sectioned preganglionically and allowed to regenerate in a group of bullfrogs with normal contralateral eighth nerve and labyrinth. Posture and reflex to lateral tilt were measured preoperatively and postoperatively for a minimum of 3 months. Similar measures were performed in a second group of bullfrogs in which the eighth nerve had been destroyed by ganglionectomy and in a third with peripheral labyrinthectomies.