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Biomedical subjects

P Poli

Publications and source records attributed to P Poli.

At least 55 records · Page 3Linked to original sources

[Pancreatico-pleural fistula in chronic pancreatitis].

Seven patients presented with a pancreatic pleural fistula in the context of chronic pancreatitis. The diagnosis was made by analysis of the pleural effusion and by endoscopic retrograde pancreatography which opacified the fistula in six cases. Surgical procedure (five resections, one Roux-en-Y drainage and one resection associated with Roux-en-Y drainage) was guided by the morphology of the pancreatic duct and the presence of pseudocysts. All patients were successfully treated by surgery.

Adult↗

Characterization of ouabain-resistant mutants of the preadipocyte Ob17 clonal line. Adipose conversion in vitro and in vivo.

After exposure to a mutagenic drug (ethylmethanesulfonate), mutant clones of Ob17 preadipose cells resistant to the cytotoxic action of ouabain have been isolated. Their ability to grow in serum-supplemented medium containing greater than or equal to 3 mM ouabain is consistent with the decreased ouabain sensitivity of K+ transport observed in one of these clones (Ob17-OR11). Ouabain-resistant mutants retain their ability to convert into adipose-like cells in vitro with a frequency similar to that of original Ob17 cells. Long-term maintenance of Ob17-OR11 cells in ouabain-enriched medium leads to a higher frequency of adipose conversion, which is linked to a rather specific and limited growth-promoting effect of the drug. Undifferentiated Ob17-OR11 cells, when injected subcutaneously into athymic mouse, give rise in vivo to a fat pad containing ouabain-resistant mature adipocytes. Therefore, Ob17-OR11 clone should be a useful tool to distinguish in vivo between intrinsic and extrinsic factors involved in the differentiation of adipose precursor cells.

Adipose Tissue↗

Temporal (phase and time) disparities in lateralization.

The topic of this paper concerns the judgement of just noticeable differences (JND) and of complete lateral position for dichotic 1 000-Hz stimuli with phase or onset time or delay differences and for a click. The 1 000-Hz sinusoids had 30 ms steady state with 10 or 50 ms rise/decay time and were presented at 50 dB HL in listeners with normal hearing. For every value of delta phi, delta onset or delay, the presentation consisted of blocks of 20 trials and the JND was determined as the phase or onset time or delay differences producing 80% of correct responses (forced choice). The intracranial 1 000-Hz tone image with long disparities was evaluated for 90, 180 and 270 degrees delta phi, for 250, 500 and 750 microseconds delta onset and for 250, 500 and 750 microseconds delay. Our results demonstrate that the interaural time differences with suitable headphone onset cues have a negligible effect on JND in pure-tone lateralization tests; the JND for a 1 000-Hz tone is based on phase cues only. With 180 and 270 degrees phase shifts, the interaural onset time differences, with 10 ms rise-fall time, become critical and override phase information. The JND for clicks on the contrary is based on time cue only. The intracranial click image with long disparities and duality threshold was evaluated.

Adult↗

Modulation of lipid-synthesizing enzymes by insulin in differentiated ob17 adipose-like cells.

ob17 cells convert into adipose-like cells when maintained in the presence of physiological concentrations of insulin and tri-iodothyronine. After this conversion, insulin removal from differentiated ob17 cells gives within 24-48 h a large decrease in fatty acid synthetase, glycerol 3-phosphate dehydrogenase and acid:CoA ligase activities, as well as in the rate of fatty acid synthesis determined by [14C]acetate incorporation into lipids. All parameters are restored by insulin addition to initial values within 24-48 h. Dose-response curves of insulin on the restoration of glycerol 3-phosphate dehydrogenase activity and of fatty acid synthesis give half-maximally effective concentrations close to 1 nM, in agreement with the affinity for insulin of the insulin receptors previously characterized in these cells. Immunotitration experiments indicate that the changes in the specific activity of fatty acid synthetase are due to parallel changes in the cellular enzyme content. Therefore the ob17 cell line should be a useful model to study the long-term effects of insulin on the modulation of lipid synthesis in adipose cells.

Acetates↗

Lipogenic and mitogenic effects of insulin during conversion of Ob17 cells to adipose-like cells.

Chronic exposure to insulin of confluent cells of a preadipocyte clonal line (Ob17) leads to an acceleration of their development into adipose cells. The short-term effects of insulin have been examined by the stimulation of [14C] alpha-aminoisobutyrate uptake and the long-term effects by the increase in the activity levels of several lipogenic enzymes and in the intracellular triacylglycerol content. These metabolic effects of insulin occur within a physiological range of concentrations (EC50 congruent to 1 nM). As compared to insulin, dose-response curves obtained with proinsulin on these parameters show at least a 10-fold decrease in sensitivity of the cells. In contrast, the growth-promoting effects of both insulin and proinsulin occur at supraphysiological concentrations (EC50 greater than 300 nM). This mitogenic response is likely mediated through binding to receptors of insulin-like growth factors. Our data demonstrate that long-term effects of insulin on lipid synthesis can be dissociated from its effect on cell growth. Therefore the Ob17 cell line should be a useful model to study the role of insulin in the regulation of lipid synthesis in adipose cells.

Adipose Tissue↗

Lateralization, impedance, auditory brain stem response and synthetic sentence audiometry in brain stem disorders.

Applied individually, the conventional audiometric tests are unsatisfactory in the diagnosis of retrocochlear disorders. An accurate identification of a retrocochlear lesion, however, is not always possible using a single test, and only an appropriate test battery provides the basis for correct prediction of a retrocochlear lesion. Because of this observation, lateralization tests, impedance studies, auditory brain stem responses and speech audiometry with synthetic sentences have been applied to patients affected with retrocochlear disorders (acute nucleoreticular vestibular syndrome, multiple sclerosis and focal lesions). Analysis of the results has demonstrated the value of the tests employed, but the various tests were not strongly correlated and are therefore complementary.

Acoustic Impedance Tests↗

Sensitivity of auditory lateralization and temporal order tests to benzodiazepines.

The responses to tests of auditory lateralization and temporal order to the administration of desmethyldiazepam (DMDZ) and of chlorodesmethyldiazepam (Cl-DMDZ) have been investigated. Therapeutic doses of these two benzodiazepines were used. We have tested four groups of 10 healthy normally hearing subjects. It was demonstrated that both DMDZ and Cl-DMDZ cause a temporary disturbance in the lateralization tests: delta i but especially delta t. The temporal order test is not altered after drug administration. The physiopathological and topodiagnostic value of these tests and the site of action of the benzodiazepines are discussed.

Adult↗

[Directional hearing, temporal order, auditory pattern: new methods of symptomatological study of the central auditory pathways. Physiological data].

New tonal audiometry tests: directional hearing, temporal order and hearing pattern were experimented in 50 healthy subjects with normal hearing. These tests involve the ability to integrate and elaborate complex tonal stimuli at the central pathway level, in addition to the perception of tonal stimuli. The method and apparatus employed are described. In spite of the complexity of the latter, the tests are rapid and easily understood by the subject. They are thus suitable for extension from the laboratory into clinical practice. Their use has shown that the central routes display a variety of capabilities at different levels, of both dynamic and static type; the former are evaluated by the directional hearing test, the latter by the other two tests.

Adult↗

Assessment of depression among cancer patients: the role of pain, cancer type and treatment.

One hundred consecutive cancer patients were assessed using two structured methods for assessing major depressive disorder-Structured Clinical Interview for DSM III-R (SCID) and Endicott criteria-and using a depression rating scale-Hamilton Depression Rating Scale (HAMD). Forty-nine percent of patients were depressed using SCID (DSM III-R criteria), whereas 29% of patients were depressed using Endicott criteria. Twenty-eight percent of patients were depressed using both criteria. Age and sex did not have any influence on the assessment of major depression. Both the structured interview and the rating scale were able to identify suicide ideation. Depressed patients were not shown to have more lifetime depression than non-depressed patients using both structured methods. Patients who were depressed using both assessments of depression had more metastasis and pain than non-depressed patients.

Adult↗

Symptomatology and comorbidity of generalized anxiety disorder in children and adolescents.

This study investigated the symptomatology and comorbidity of generalized anxiety disorder (GAD) in a clinically referred sample of Italian children and adolescents as a function of age and gender. The sample consisted of 58 subjects (19 children and 39 adolescents), 23 males and 35 females screened from consecutively referred children and adolescents. This sample was divided into two groups of younger children (19 subjects, eight males and 11 females aged 7 to 12 years; mean age, 9.6) and adolescents (39 subjects, 15 males and 24 females aged 12 to 18 years; mean age, 14.9). Feelings of tension, apprehension, the need for reassurance, irritability, negative self-image, and physical complaints were reported in more than 70% of the subjects. Differences in the symptomatic profile between males and females were not significant. Children and adolescents did not show significant differences in the number of symptoms. The need for reassurance was significantly more frequent in children, and brooding was more frequent in adolescents. Other anxiety disorders were commonly comorbid with GAD. More than half of the patients with GAD showed a concurrent depressive disorder; no differences were found for comorbidity between children and adolescents, except for higher rates of separation anxiety disorder in children.

Adolescent↗

Depressive symptoms and academic self-image in adolescence.

The aim of this paper was to specifically analyse the relationship between the different components of academic self-image, defined as the way adolescents represent themselves as students, and self-reported depressive symptoms, assessed with the Children's Depression Inventory (CDI), in a non-clinical sample of 298 adolescents. We considered both adolescents' beliefs about their own cognitive functioning in academic performance and beliefs about their emotional attitude in achievement situations. Our data indicate that the pattern of correlation between emotional beliefs about schooling and learning are significantly related to CDI scores, but this correlation is not evident for the cognitive beliefs. This pattern of correlation is affected by actual school functioning, because correlation between CDI and beliefs is much more significant in subjects without school failure. Differences between gender in CDI scores, beliefs about schooling and learning, and pattern of correlation are considered. These results can enable to focus supporting psychological interventions on more specific targets.

Achievement↗

Modifications of the stapedius muscle reflex under spontaneous and experimental brain-stem impairment.

An oscilloscopic plus a graphic method of recording of the stapedius muscle reflex has revealed peculiar modifications in the latency, threshold, and shape of development of the reflex in cases of brain-stem impairment. Many subjects have been examined who were affected by nucleo-reticular vestibular syndrome, vascular insufficiency, disseminated sclerosis, tumours, etc. and a comparison has also been made in normal subjects and in the same subjects during a temporary impairment of the brain-stem structures following barbiturate administration. The greatest semeiological value is attributed to the modifications in the shape of the reflex.

Adolescent↗