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At least 1,243 records · Page 69Linked to original sources
PubMed2001

Spontaneous cerebrospinal fluid rhinorrhea associated with chronic renal failure--case report.

A 39-year-old woman was admitted with complaints of headache and nasal discharge on the left for 3 months which was later on proved to be cerebrospinal fluid (CSF). Neurological examination found no abnormalities except bilateral papilledema. Neuroimaging demonstrated enlargement of the lamina cribrosa foramina through which the olfactory nerves pass, as well as empty sella and cerebral cortical atrophy. Bone mineral densitometry showed osteopenia. CSF Ca++ and blood parathyroid hormone levels were elevated. CSF pressure was 280 mmH2O. Bilateral frontal craniotomy was performed to expose the anterior fossa. Foraminal enlargement at the lamina cribrosa was confirmed, and islands of extra-osseous calcifications on the arachnoid membrane were identified. The base of the anterior fossa was repaired intradurally with fascial graft and fibrin glue on both sides. No CSF leakage was noted at 1-year follow up. Spontaneous CSF leakage probably resulted from enlargement of the foramina at the lamina cribrosa due to Ca++ mobilization from bones and pseudotumor cerebri not to the extent of hydrocephalus caused by poor CSF absorption at the arachnoid granulations obliterated by extra-osseous calcareous accumulation.

Adult↗
PubMedDate not supplied

[The effect of age on the sense of smell in health individuals].

INTRODUCTION: A need for research of the olfactory function exists in everyday clinical work. The aim of this study was to determine standards for perception and identification thresholds regarding olfactory substances in healthy subjects in regard to their age. MATERIAL AND METHODS: The research included 120 healthy examinees (60 women and 60 men) classified according to age into three age groups (20-30, 31-40, 41-50 years of age). This examination was done using Fortunato-Niccolini's method. RESULTS AND DISCUSSION: The results of this work show that olfactory function becomes significantly weaker after the age of forty. Thresholds of perception in correlation with thresholds of identification for examined olfactory substances are significantly lower in older age groups. CONCLUSION: A gradual loss of olfactory capability with age can be explained by gradual destruction of olfactory cells and fibres of olfactory nerves during life.

Adult↗
PubMed1982

Cerebrospinal fluid drainage as influenced by ventricular pressure in the rabbit.

Artificial cerebrospinal fluid (CSF) containing radioisotope iodinated (125I) serum albumin (RISA) and either blue dextran or indigo carmine was given to white New Zealand rabbits over 4 hours. In one group it was given by ventriculocisternal perfusion, in one by ventricular infusion, and in one by cisterna magna infusion. Blood was sampled continuously from the superior sagittal sinus (SSS) or intermittently from the systemic arterial circulation. Removal of CSF from the cisterna magna during the ventriculocisternal perfusion kept the intracranial pressure (ICP) at 0 to 5 torr, whereas ventricular or cisterna magna infusion raised the ICP to 20 to 30 torr and 15 to 20 torr, respectively. In the two groups with raised ICP, an increased concentration of RISA was present in the optic nerves, olfactory bulbs, episcleral tissue, and deep cervical lymph nodes; but this was not found in the group with normal ICP. In all three groups, the concentration of RISA in the SSS blood was the same as in the systemic arterial blood. The concentration gradient of RISA across the cerebral cortex was similar in both the ventriculocisternal perfusion and the ventricular infusion groups. With cisterna magna infusion, the concentration of RISA was the same on the cortical surface and less in the ventricles compared with the ventricular infusion. It is concluded that, with elevated ICP, CSF drained via pathways that are less evident under normal pressure. Drainage of CSF was similar irrespective of whether the infusion site was the ventricles or cisterna magna. It did not appear that acute dilatation of the ventricles during ventricular infusion compromised the subarachnoid space over the surface of the hemisphere, as the concentration of RISA on the convexities and in the SSS blood did not significantly differ between the groups. Transcortical bulk transfer of CSF was not evident with raised ICP.

Animals↗
PubMed1986

Ultrastructural morphology of the olfactory pathway for cerebrospinal fluid drainage in the rabbit.

Previous physiological studies indicate that the olfactory region serves as a major pathway for cerebrospinal fluid (CSF) drainage into the lymphatic system. The present study was undertaken to determine the ultrastructural characteristics of this egress route. New Zealand White rabbits received a single bolus injection of the tracer ferritin (MW 400,000) into both lateral ventricles in such a manner as not to raise the intraventricular pressure above the normal level. The animals were sacrificed via intracardiac perfusion of fixative between less than 12 minutes and 4 hours following injection. The cribriform region was removed en bloc, decalcified, sectioned coronally, and prepared for light and electron microscopic examination. The arachnoid, dura, and periosteum surrounding the fila olfactoria passing through the cribriform plate merge together and form the perineurium, which consists of multiple layers of loosely overlapping cells with widely separated junctions and few vesicles. The perineurium surrounding the olfactory filaments at the superficial submucosal level is only one cell thick. The subarachnoid space freely communicates with the perineural space surrounding each filament. No morphological barrier between the perineural space and the loose submucosal connective tissue was identified. Whether or not the perineurium was multi- or single-layered, ferritin was noted in abundance between the loosely overlapping perineural cells and in the submucosal connective tissue. The distribution of ferritin at 12 minutes was similar to that at 4 hours; however, the quantity of ferritin was increased at 4 hours. These results indicate that no significant barrier to CSF drainage is present at the rabbit cribriform region and that CSF reaches the submucosal region rapidly via open pathways.

Animals↗
PubMed1990

Anosmia following operation for cerebral aneurysms in the anterior circulation.

Damage to the olfactory nerve during frontotemporal approach to the basal cisternal region has not previously been investigated in a quantified manner. In this retrospective study of 25 patients operated on for ruptured intracranial aneurysms via the frontotemporal route, 22 patients suffered postoperatively from anosmia ipsilateral to the side of surgery. This complication most often goes unrecognized by the patient as well as the physician, and attention should be drawn to it because of its widespread occurrence. This investigation demonstrates a high incidence of anosmia (24 (88.9%) of 27 surgical sides) occurring ipsilateral to the frontotemporal approach in aneurysm surgery. Recovery after traumatic anosmia has been recorded up to 5 years after injury. Nevertheless, the authors believe that the damage is permanent when lasting 35 months or longer.

Adult↗
PubMed1992

The production and characterization of anti-Naegleria fowleri monoclonal antibodies.

Naegleria fowleri, a free-living amoeba commonly found in moist soil and fresh water, enters the body via the nasal mucosa and migrates along the olfactory nerve to the brain, where it causes acute amoebic meningoencephalitis. In the present study 7 clones secreting monoclonal antibodies (McAbs) against N. fowleri were produced and the effector function of them was investigated. Their isotypes were IgG1 (Nf 1, Nf 154), IgG3 (Nf 137) and IgA (Nf 1, Nf 2, Nf 256, Nf 279). Five McAbs (McAb Nf 2, Nf 279, Nf 27, Nf 154, Nf 137) were specific for N. fowleri by ELISA and recognized the antigenic determinants located on the trophozoite surface by IFAT and immunoperoxidase stain. These five McAbs had capacity to agglutinate N. fowleri trophozoites and inhibited the growth of the amoeba in culture medium. McAb Nf 2 inhibited proliferation of trophozoites in vitro significantly. Also the cytotoxicity of N. fowleri against CHO cell was reduced in the presence of McAb Nf 2 and McAb Nf 154. From these results McAb Nf 2 was confirmed to weaken the virulence of the amoeba among 7 screened McAbs.

Animals↗
PubMed1975

Campomelic dwarfism.

The campomelic syndrome is a short-limb, usually fatal, neonatal dwarfism. It is characterized by bowed lower limbs, especially the tibia, usually associated with a cutaneous dimple over the anterior skin. There is delayed calcification of the epiphyses and delayed mineralization of the spine and pelvis. The cartilages of the tracheobronchial tree are hypoplastic, contributing to death from respiratory problems. Other associated abnormalities are unusual appearing facies, cleft palate, absent olfactory nerves and talipes equinovarus. Less commonly seen are cardiac, renal and brain anomalies.

Adult↗
PubMed2001

Functional magnetic resonance imaging of human olfaction.

Olfaction is our basic sense phylogenetically and embryologically. Little is known, however, about how the human brain encodes the quality of odors, odor-associated memories, and emotions. Olfactory information is projected from the olfactory bulb to the primary olfactory cortex, which is composed of the anterior olfactory nucleus, the olfactory tubercle, the piriform cortex, the amygdala, the periamygdaloid region, and the entorhinal cortex. From there, the primary olfactory cortex projects to secondary olfactory regions including the hippocampus, ventral striatum and pallidum, hypothalamus, thalamus, orbitofrontal cortex, agranular insular cortex, and cingulate gyrus. Functional MR studies using olfactory stimuli as paradigms show activation of many of these areas and can advance our understanding of odor perception in humans.

Adult↗
PubMed1975

The claustrum in the dog brain.

The structure of the claustrum was studied in the dog brain using Weigert's, Klüver-Barrera's, Manns' and Nissl's methods. It consists of two main parts arranged one above the other. The dorsal part is situated in the depth of the neocortex and extends from the gyrus orbitalis to the gyrus compositus posterior. The ventral part of the claustrum underlying the olfactory cortex continues from the cuadal fragments of the olfactory peduncle to the entorhinal area, where it fuses with its deep layers. The claustrum can be regarded as a fragment of a bigger cellular formation present in different parts of the hemisphere.

Animals↗
PubMed2003

DLX5 regulates development of peripheral and central components of the olfactory system.

Induction, neurogenesis, and synaptogenesis of the olfactory bulb are thought to require interactions with the olfactory epithelium. The Dlx family of homeobox genes is expressed in both the olfactory bulb and olfactory epithelium. In particular, Dlx5 is expressed in the olfactory placode, olfactory epithelium, and local circuit neurons of the olfactory bulb. Here we analyzed mice lacking DLX5 function. The Dlx5-/- mutation reduces the size of the olfactory epithelium. Although some olfactory neurons are formed, they fail to generate olfactory axons that innervate the olfactory bulb. Despite the lack of innervation, the olfactory bulb forms, and neurogenesis of projection and local circuit neurons proceeds. However, the mutation has a cell-autonomous effect on the ability of neural progenitors to produce olfactory bulb local circuit neurons, with granule cells more severely affected than periglomerular cells. In addition, the mutation has a noncell-autonomous effect on the morphogenesis of mitral cells.

Animals↗
PubMedDate not supplied

[Neurobiological relations and aging].

Of the different aspects of a series of neurobiological changes that take place throughout the life cycle of an individual, in this paper we examine those involved in the aging process. These changes have been associated on different scales, including on a macroscopic level, that take into account variations in the shape, weight and volume of the brain and other encephalic structures. A part of the information about the weight seems to be incompatible and hence its incompatibility has been questioned and argued from a quantitative perspective. The functional option has been proposed as an alternative in the maintenance of normal brain functioning, as have changes on the microscopic scale in neuronal processes, the reduction in number of neurons in certain parts of the brain, which has also been questioned for the case of olfactory nerve fibres, and finally changes that take place on the molecular scale in the alteration of some neurotransmitters in certain parts, modifications suffered by mitochondrial enzymes and others that depend on the genome. These aspects have all been taken into consideration along with a resulting physiological relation in an attempt to gain a slightly more holistic, although still fragmented, view of the process, and to consider neoteny as an evolutionary strategy in the human species that serves to maintain brain functioning.

Aging↗
PubMed1999

[Olfactory evoked potentials produced by electrical stimulation of the olfactory mucosa].

OBJECTIVE: To develop an objective olfactometric method. METHODS: Electrically evoked olfactory potentials were recorded in 20 rabbits with 0.2-4.0 mA electrical stimulations. The stimulating electrodes were placed on the olfactory and respiratory regions of the nasal mucosa. Recording electrode was placed on the scalp near the olfactory bulb. RESULTS: Electrically evoked olfactory potentials composed of triphasic negative-positive-negative peaks, named N1, P1, N2 respectively, were detected on the olfactory region. The latencies of N1, P1, N2 were 16.27 ms, 25.36 ms, 49.75 ms respectively in cribriform plate. No electrically evoked potentials were detected on the respiratory mucosa, nor did on the olfactory mucosa after olfactory neurectomy. CONCLUSION: Steady and clear electrically evoked olfactory potentials which originated from olfactory neurosystem were detected on olfactory mucosa in rabbits.

Animals↗
PubMedDate not supplied

[Smell during speleologic isolation].

A smell evolution it is done from two isolation experiences, in a cave by a speologyst in Eastern Pyriness. The investigation verified the smell recovery from a person who is used to living in town with big pollution. This work was done with twenty four fragrant essences, twenty of them were oriented to olfactory nerve exploration and four of them to trigeminal response. These tests were done with each nostril separately.

Adult↗