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Biomedical subjects

E Mira

Publications and source records attributed to E Mira.

At least 73 records · Page 4Linked to original sources

Insulin short-term control of rat liver alpha 2-microglobulin gene transcription.

By differential screening of a rat liver cDNA library, we have isolated several cDNA clones whose respective mRNAs are decreased in liver from diabetic rats. One such clone corresponding by DNA sequence to alpha 2-microglobulin mRNA has been used in the present study. As it was described previously a reduction (10 times) of alpha 2-microglobulin mRNA levels is observed in liver from diabetic animals. Insulin both in vivo and in isolated hepatocytes from diabetic rats is able to increase the level of alpha 2-microglobulin mRNA within 15 min. This fast effect of insulin is dose-dependent (half-maximal dose at 10(-10) M), indicating that it is likely to be mediated through the insulin receptor. Insulin induction is primarily due to an increase in the rate of transcription of the gene as judged by nuclear run-on transcription experiments and by its complete prevention with actinomycin D. These data indicate that alpha 2-microglobulin gene is a fast insulin-responsive gene and constitutes a good model gene to study the possible regulatory sequences involved in the control of gene transcription by insulin.

Alpha-Globulins↗

Presence of phospholipidic lamellar bodies on the mucosa of rabbit eustachian tube. Ultrastructural aspects.

Electron microscopy of the rabbit eustachian tube showed the presence of osmiophilic lamellar bodies in the cytoplasm of secretory cells and of osmiophilic free lamellar membranes in the lumen of tubal glands or above the epithelium. Similar structures have been reported in other parts of the respiratory system and in the pulmonary alveoli. The functional significance of these morphological observations is suggestive of a surface-tension-lowering effect on the mucosal lining layer of the eustachian tube and of a possible relationship to the phospholipid surfactant of the lung.

Animals↗

Iron status in children undergoing tonsillectomy and its short-term modification following surgery.

Red cell and iron status parameters were studied in a group of 44 children undergoing tonsillectomy for recurrent throat infections and in a control group of 40 healthy children. In the patient group, before tonsillectomy, 8 children presented a latent iron deficiency and 15 a decrease in serum ferritin levels. This altered iron status can be attributed to a reduced intestinal iron absorption, due to recurrent infections. One and seven days following surgery there was a significant fall in serum iron, serum transferrin and transferrin saturation, in parallel with an increase of serum ferritin and alpha-2 globulins levels. These modifications cannot be attributed to the blood loss, as proven by the constancy of haemoglobin level and of other red cell parameters, but to an unspecific reaction to surgical stress, as observed in fever, traumas and inflammation. They reflect an altered processing of iron, with a temporary block of its release to plasma and an increased storage within the reticuloendothelial cells.

Child↗

[Current computerized support for vestibular function tests. II. An expert system for the classification of vertigo].

A computerized system (VERTIGO) aimed to the classification and diagnosis of different types of vertigo has been developed. It is based on the shell EXPERT (Weiss and Kulikowski, 1979). At present only the findings arising from patient history are considered as input data and the diagnostic possibilities of the system have been limited to the differential diagnosis of vertigo due to peripheral vestibular disorders. About thirty different forms of vertigo are taken into account. They are clustered in two groups, true vertigo and dizziness. Data are collected through a computer controlled questionnaire. Using the facilities offered by EXPERT, the sequence of the questions can be modified according to the flow of information in order to reproduce different diagnostic strategies. After history taking, the system presents a summary of the available findings followed by its diagnostic conclusions. Different conclusions can be proposed with different degrees of certainty. Conclusions can be justified by the system when required.

Adult↗

[Current computerized support for vestibular function tests.I. Expert systems and their clinical applications].

Expert Systems are a new method developed by the branch of Computer Science known as Artificial Intelligence in order to make available the knowledge and the expertise of the specialists in a certain domain of the science to other operators in the same field. Most of their applications belong to the medical domain. In this paper the main features of the expert systems are briefly described. As an example the structure and the characteristics of the shell EXPERT (Weiss and Kulikowski, 1979) are presented in detail. This shell has already been used to develop several expert systems. It is the tool by which we constructed a consultation system (VERTIGO) aimed to classify different types of vertigo.

Expert Systems↗

Polygraphic study of vestibular stimulation in epileptic patients.

Vertigo, vestibular function and the effect of labyrinthine stimulation on the EEG were studied in 29 epileptic patients. Vertigo has no distinguishing characteristics and the epileptic nature of this symptom can be only tentatively inferred from its chronological relationship with the other epileptic features. In a high percentage of epileptic subjects, especially those with focal seizures, abnormal vestibular responses can be observed. This finding may be ascribed to the existence of a common cerebral lesion responsible for both focal seizures and vestibular abnormalities, even though the data do not allow us to exclude the role played by antiepileptic treatment in modifying the vestibular response. Caloric labyrinthine stimulation in the method employed by us shows a limited activating effect on the EEG and clinical epileptic pattern. Even in the positive cases this method does not allow us to reach any precise anatomo-physiological conclusions.

Adolescent↗

Benign paroxysmal vertigo in childhood: a migraine equivalent.

The two main problems in defining and classifying the syndrome of benign paroxysmal vertigo (BPV) in childhood are the vestibular function pattern and the relationship between BPV and migraine. 13 children suffering from this syndrome were submitted to complete otoneurological examination, including caloric and rotational labyrinthine stimulation with ENG recording, and to headache provocation tests with nitroglycerin, histamine and fenfluramine. Vestibular responses were normal in all except 2 cases which presented signs of central vestibular impairment at the level of the vestibulocerebellar pathways. Headache provocation tests were positive in 9 out of 10 children, and in 4 cases they induced a typical vertiginous attack instead of headache. In addition, several children had a positive family history for migraine, headache was frequently associated with the crisis and other signs of a 'periodic syndrome' (motion sickness, cyclic vomiting, abdominal pain) were present, unrelated to vertiginous attacks. During the follow-up period, some children responded positively to migraine treatment. BPV, like paroxysmal torticollis in infancy and the signs of the periodic syndrome, can be considered a migraine equivalent or a migraine precursor and could be due to the same vascular and/or biochemical mechanisms responsible for the migraine. In children, for anatomical or developmental reasons, these mechanisms could selectively affect parts of the brain stem, including the vestibular nuclei and vestibulocerebellar pathways.

Child↗

Benign paroxysmal vertigo in childhood. Diagnostic significance of vestibular examination and headache provocation tests.

Sixteen children with benign paroxysmal vertigo (BPV) are presented. The great majority had a family history of migraine, neurological and autonomic signs associated with vertiginous attacks, and headache or other sign of the periodic syndrome (motion sickness, cyclic vomiting, abdominal pain) unrelated to the attacks. Vestibular examination, including bithermal caloric and rotational testing with ENG recording, showed normal or transiently decreased vestibular function. Headache provocation tests with nitroglycerin, histamine and fenfluramine were positive in 9 of the 13 patients examined, and in 4 cases induced a typical vertiginous attack instead of headache. BPV can be considered a migraine precursor or a migraine equivalent, attributable to the same vascular and/or biochemical disturbances responsible for migraine.

Child↗

IgM and IgD concentrations in the serum and secretions of children with selective IgA deficiency.

Serum IgG and serum and secretory IgM, IgA and IgD levels were determined in 14 children with selective IgA deficiency and in 12 age and sex matched healthy controls. IgD was determined using a highly sensitive ELISA technique. In the healthy controls serum IgG, IgA and IgM were all in the age normal range, and serum IgA was significantly higher than secretory IgA with IgA in nasal secretions being significantly higher than in saliva. In the IgA deficient children serum IgG and IgM and secretory IgM were present in higher concentrations than in the controls but the difference was statistically significant only for serum IgG and salivary IgM. IgD was detectable in the serum and secretions of all patients and all but one control subject. Like IgM, serum IgD levels were significantly higher than secretory IgD levels and IgD was present in greater concentrations in nasal secretions than in saliva both in the patients and the controls, with no difference between the two groups. Thus, the data of this study show that while serum and secretory IgM levels are elevated in children with selective IgA deficiency, serum and secretory IgD are present in normal concentrations, supporting the hypothesis of a compensatory increase in IgM but not in IgD in such patients.

Adolescent↗

Oculomotor abnormalities after labyrinthine and cerebellar lesion. A case report.

A subject presenting a rare association of left labyrinthine and left hemispheric cerebellar lesion was examined, with recording and analysis of eye movements at different intervals. A complete compensation of the vestibular deficit and recovery of cerebellar postural ataxia, with persistence of limb incoordination and oculomotor abnormalities, were observed. The saccadic, smooth pursuit and optokinetic nystagmus systems were impaired. Ocular signs, in combination, may suggest a cerebellar dysfunction but they do not supply sufficient diagnostic criteria for localizing the cerebellar damage. Only the direction-specific impairment of smooth pursuit and optokinetic nystagmus is indicative of the side of the lesion.

Ataxia↗

Impaired suppression of vestibular nystagmus by fixation of visual and acoustic targets in neurological patients.

Suppression of vestibular nystagmus induced by fixation of visual and acoustic targets moving with the head during sinusoidal rotation (0.1 Hz, 75 degrees/second peak velocity) was tested in cerebellar and noncerebellar patients. Visual suppression was impaired greatly in cerebellar patients, without correlation with visual smooth-pursuit defects. Acoustic suppression was equal to or slightly weaker than visual suppression. In noncerebellar patients, a disturbance of visual suppression was found only in the presence of a severe impairment of pursuit eye movements. Acoustic suppression did not parallel the visual-suppression pattern. In clinical vestibular examination, an impaired modulation of the vestibulo-ocular reflex suggests a cerebellar dysfunction, but also can occur in the presence of disorders of other parts of the CNS severely affecting the SP system.

Attention↗