Do the genes that cause otosclerosis reduce susceptibility to otitis media?

Hypothesis: The genetic factors that cause otosclerosis reduce susceptibility to otitis media.

Background: Susceptibility to some infectious diseases is modulated by host genetic factors. Genes that reduce the morbidity and mortality of infectious diseases may confer a selective advantage and achieve high-frequency in at-risk populations.

Linkage of otosclerosis to a third locus (OTSC3) on human chromosome 6p21.3-22.3.

Clinical otosclerosis (OMIM 166800/605727) has a prevalence of 0.2-1% among white adults, making it the single most common cause of hearing impairment in this group. It is caused by abnormal bone homeostasis of the otic capsule with the consequent development of sclerotic foci that invade the stapedio-vestibular joint (oval window) interfering with free motion of the stapes.

Otorhinolaryngology through the works of Hippocrates.

This retrospective survey refers to the philosophers and first scientists of the pre-Hippocratic era, which included the foundation of schools in Greece at the time (e.g. Ionia, South Sicily, Kyrinia).

Synaptic alterations in the vestibulocerebellar system in Alzheimer's disease--a Golgi and electron microscope study.

Alzheimer's disease is one of the main causes of cognitive impairment in the presenium and senium. Despite increased efforts in investigations of the aetiological background of the disease, most of the pathogenetic mechanisms remain unclear. From the morphological point of view, neurofibrillary degeneration and neuritic plaques, the main hallmarks of Alzheimer's disease, are mostly seen in the hippocampus and the cortex of the cerebral hemispheres.

The acoustic cortex in frontal dementia.

Frontal dementia is a clinical entity of cognitive impairment, characterized mostly by progressive loss of fluency in speech, eventually resulting in aphasia or anomia, associated frequently with early loss of insight and many forms of inappropriate behavior. Hyperphosphorylation of the isoforms of tau protein, a microtubule-associated protein, which plays an important role in the pathogenetic mechanisms of Alzheimer's disease, is mainly involved in the pathogenesis of frontal dementia. In the present study, the morphological alterations of the acoustic cortex are described in three cases of dementia who fulfilled all the clinical and neuropathological criteria of frontal dementia.

Synaptic alterations in acoustic cortex in Creutzfeldt-Jacob disease.

The acoustic cortex was studied in electron microscope in 10 cases of Creutzfeldt-Jacob disease. The most prominent finding was the tremendous loss of neurons associated with marked reactive astrocytosis. The so called Cajal-Retzius cell had completely disappeared in the first cortical layer.

Treatment of secretory otitis media with local instillation of hydroxyzine.

The study is a preliminary single-blind, placebo- and prednisolone-controlled investigation of the treatment of 156 children with otitis media with effusion (secretory otitis media, SOM), ranging from 2 to 12 years. The protocol involved tympanotomy and placement of a ventilation tube (grommet), through which control or drug solutions were introduced. Other parameters and coexisting symptoms which could contribute to SOM were also examined.

The acoustic cortex in Alzheimer's disease.

The morphology of the acoustic cortex was studied in light and electron microscopy, in 6 post mortem cases of Alzheimer's disease. Silver impregnation techniques and routine stainings were applied for the study of the cytoarchitecture and the cellular morphology of the acoustic cortex. Samples from every part of the acoustic cortex were processed for electron microscopy.

Ultrastructural changes of stapedius muscle and stapedius branch nerve endings in otosclerotic patients.

We studied in the electron microscope 12 stapedius muscles and stapedius branches of the facial nerve excised from otosclerotic patients who underwent stapedectomy for hearing restoration. Almost all of the stapedius, muscles demonstrated morphological alterations, such as accumulation of lipids and osmiophilic material, dilatation of the sarcoplasmic reticulum, sarcoplasmic invaginations of the nuclei and accumulation of fibroblasts and satellite cells on the surface of the muscle fibers. The stapedius branch of the facial nerve demonstrated a marked loss of myelinated fibers.

Substance P in the acoustic area of the cortex during neuronal development and maturation.

Substance P has been proved an important neurotransmitter and neuromodulator, serving not only as an excitatory transmitter of the first afferent synapse of pain pathways but as a valuable neuromodulator in the primary cortical areas of sensosensorial integration. In the human acoustic cortex, substance P has been found in the presynaptic terminals as well as in the cell bodies of numerous polyhedral, triangular and bipolar neurons. Using histochemical techniques, we found recently that substance P is first accumulated in the neuronal elements of the human acoustic cortex in 18-gestational-week (GW) fetuses.

Controlled hypotension during anesthesia for otologic operations. An ultrastructural study of the brain in an experimental animal model.

We have studied the fine structure of the cerebral cortex, the cerebellar cortex, the thalamus, the caudate nucleus, the amygdala, the putamen, the vestibular nuclei, the substantia nigra, the hippocampus and the centrum semiovale in a canine model following 20 min controlled hypotension by the administration of sodium nitroprusside. The neurons and the astrocytes of all structures were intact morphologically. The synapses in the cerebral and cerebellar cortex were all unremarkable.

The neuropeptides in the acoustic cortex. I. Substance P.

Peptides are the most recently studied chemical category of neurotransmitters. Most of them are found located in special diencephalic neurons and in some cortical areas serving as transmitters for specific synaptic junctions. In the human acoustic cortex we tried to identify substance P which may participate in the synaptic transmission at the various morphological types of synapses.

Pathology of acoustic nerve Schwannoma in vivo and in vitro.

The ultrastructural pattern of the acoustic nerve Schwannoma was studied on surgically excised tumours and on explants cultured in vitro. The typical neoplastic cell is elongated, spindle-shaped, coated with basement membrane and numerous protruding cellular processes. Cells demonstrating numerous microfilaments are also seen, sometimes intermixed with the typical spindle-shaped cells.

Perforated synapses in the acoustic area of the human brain.

Morphological studies were made of human acoustic cortex by light and electron microscopy. The synapses of the cortical neurons were described and their morphology was correlated with the morphology of the neurons on each cortical layer. Most of the synapses are triangular, disc-like, ovoid fusiform or mushroom-shaped.

Ultrastructural alterations of the vestibular nuclei in Jacob-Creutzfeld disease.

The morphological alterations of the vestibular nuclei in a case of Jacob-Creutzfeld disease were studied with light and electron microscope. The most prominent histological findings were the neuronal degeneration and neuronal loss resulting in a marked decrease of the total population, the increased reactive astrocytosis which demonstrated an extensive perivascular arrangement, the microgliosis and the interstitial spongiosis. At the ultrastructural level a marked dilatation of the astrocytic processes was seen.

Otological findings in cervico-oculo-auditory dysplasia.

A case of congenital ear dysplasia, combined with cleft palate and anomalies of the cervical spine and eyes, is described. The case belongs to the group of cervico-ocular-auditory dysplasias (Klippel-Feil syndrome). A strange feature in our case was the co-existence of conductive hypakousia in the right ear, due to congenital fixation of the stapes footplate, with perceptive deafness in the left ear, due to dysplasia of the cochlea and internal auditory meatus.

[Sudden deafness and vestibular failure in the cervical syndrome (author's transl)].

Acute onset deafness with vestibular failure in the cervical syndrome could be due to embolism of the labyrinthine artery. Probably the symptomatology of the cervical syndrome developes independantly. Two patients with sudden deafness and vestibular failure are reported.

Stapes gusher and Klippel-Feil syndrome.

The stapes gusher which is the most dramatic complication of stapedectomy arises from an abnormal communication between the subarchnoid and perilymphatic spaces. This congenital defect may be associated with other anomalies such as the Klippel-Feil syndrome. Two cases of stapes gusher in patients with congenital fixation of the footplate are described.

[Vagus neurinoma of the basic of the skull and endocranium (author's transl)].

We are discussing a case of neurinoma of the tenth cranial nerve in the area of the base of the skull with endocranial extension in a 51-years-old female patients. The first symptom was hoarseness of the voice, and three years later more cranialnerves were involved (V-VII-X-XI-XII). The existence and the extension of the tumor was verified by radiological examination of the base of the skull, carotic angiography, myelography and scanning; the diagnosis was proved by biopsy.