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Biomedical subjects

D Miceli

Publications and source records attributed to D Miceli.

At least 73 records · Page 4Linked to original sources
PubMed1982

Thalamo-hyperstriatal projections in the pigeon (Columbia livia) as demonstrated by retrograde double-labeling with fluorescent tracers.

Thalamo-hyperstriatal projections were studied in the pigeon by retrograde thalamic labeling following bilateral injections of different combinations of fluorescent substances (Fast Blue, Evans Blue, Nuclear Yellow) into the hyperstriatum. The distribution of single and double-labeled neurons within the thalamic nuclei dorsolateralis anterior and superficialis parvocellularis indicated the presence of distinct functional sub-regions containing neuronal populations providing ascending projections which were either ipsilateral, contralateral or bilateral via collateral axon branching.

Animals↗
PubMed1982

Effects of combined alpha- and beta-blockade by labetalol in patients with coronary artery disease.

1 The effect of labetalol 100 mg orally twice daily on exercise tolerance has been compared with placebo in 19 normotensive subjects with angiographic evidence of coronary artery disease. 2 Labetalol, at the same work load as during placebo exercise, significantly reduced systolic and diastolic blood pressures, as well as heart rate and rate-pressure product. 3 Similarly, ST segment depression was reduced by labetalol from 2.0 +/- 0.4 to 1.36 +/- 0.6 mm (P less than 0.001), thus enabling an increase in exercise tolerance from a control value of 83.7 +/- 18 to 95.3 +/- 19 W (P less than 0.005). 4 In seven other patients, also with coronary artery disease, the haemodynamic effects of a single 0.6 mg/kg intravenous dose of the drug was evaluated during exercise. 5 Compared with conditions during control exercise, labetalol induced a significant reduction in rate-pressure product from 17228 +/- 2375 to 13445 +/- 2404 mmHg/min (P less than 0.005) and in peripheral vascular resistance from 612.0 +/- 61.2 to 512.7 +/- 36.2 dyn cm-5 m-2 (P less than 0.0025). These events were not accompanied by any change in cardiac index and in dP/dT left ventricular end-diastolic pressure (LVEDP) ratio. 6 These data suggest that labetalol may induce reduction in myocardial oxygen consumption, thereby increasing exercise tolerance in patients with coronary artery disease, without impairment of left ventricular performance.

Adult↗
PubMed1981

The retinofugal pathways in the primitive African bony fish Polypterus senegalus (Cuvier, 1829).

Retinal projections were studied using Fink-Heimer and radioautographic methods in Polypterus senegalus, a species which is representative of a small group of African fresh-water bony fish often considered to be very primitive. The large optic nerve showed partial decussation at the chiasm. Two major contralateral tracts were observed: the axillary and marginal optic tracts, with the latter being subdivided posteriorly into the tractus opticus medialis and tractus opticus lateralis. The retina projected onto the: (1) hypothalamus (area optica postoptica); (2) thalamus (nucleus opticus dorsolateralis thalimi, nucleus dorsomedialis thalami, corpus geniculatum laterale, area optica dorsolateralis thalami, area optica ventrolateralis thalami); (3) pretectum (nuclei commissurae posterioris, pretectalis ventralis, pretectalis dorsalis); and (4) optic tectum (stratum marginale, stratum opticum, stratum griseum et fibrosum superficiale, stratum griseum et album centrale, stratum griseum et fibrosum periventriculare). Ipsilateral retinal projections were demonstrated to the same 4 levels and more precisely to the nucleus opticus dorsolateralis thalami, area optica dorsolaterale thalami, nucleus commissurae posterioris, stratum marginale and stratum griseum et album centrale. The existence of a retinal projection to the mesencephalic tegmentum is discussed. Comparing the primary optic system of Polypterus with that of other jawed vertebrates, and particularly with that of other bony fish, indicated that this species possesses a combination of characteristics which are both actinopterygian and sarcopterygian. The phylogenetic significance of this mozaic anatomical arrangement is discussed.

Animals↗
PubMed1981

His bundle electrogram recording using a multipolar electrode catheter via the arm veins.

In eighteen patients with atrioventricular conduction disturbance, His bundle electrograms were studied via the arm vein. A 6F Berkovits-Castellanos USCI hexapolar electrode catheter was introduced into the right atrium and looped across the tricuspid valve in a "golf club" shape. The main aim was to leave the two distal electrodes in contact with the atrial endocardium to perform atrial pacing, while displaying the other four electrodes along the superior angle of the tricuspid valve for proximal and distal His bundle recordings. His bundle electrograms were successfully obtained in all cases. The arm approach provides an alternate route whenever the femoral approach is not feasible. Moreover, the use of an hexapolar electrode catheter provides some practical advantages: 1) it enables atrial pacing to be performed, as well as proximal and distal His bundle recording to be obtained, by using the same multipolar electrode catheter; and 2) it allows long-term monitoring of His bundle potentials, in view of the stability of His bundle recordings. Finally, the arm approach could be the method of choice for the study of His bundle electrograms during leg supine exercise in selected patients.

Arm↗
PubMed1981

Clinical hemodynamic and angiographic findings in 94 patients with old myocardial infarction. Comparison with 79 patients with coronary artery disease and no myocardial infarction.

Clinical, hemodynamic, coronary arteriographic, and ventriculographic findings of 94 patients (pts) with coronary artery disease (CAD) and old myocardial infarction (MI) have been described and compared with those of 70 pts with CAD and no previous MI. Pts with old MI presented a more compromised functional and hemodynamic status, with a higher incidence of NYHA class III-IV pts (40%), symptoms of left ventricular (LV) failure (31%), cardiomegaly (70%), higher left ventricular end-diastolic pressure (LVEDP) (19.6 +/- 9.6 mmHg, p less than 0.05), compared with 32%, 22%, 54% and 16.0 +/- 6.8 mmHg respectively in CAD pts with no MI. MI pts presented more severe CAD, higher incidences of three vessel disease (56%, p less than .005) and of left anterior descending (LAD) (34%) and right coronary artery (RCA) (36%) occlusions, compared with 34%, 6%, and 9% respectively in pts with no MI. Furthermore, pts with old MI showed more diffused and severe LV segmental wall contraction abnormalities, with higher frequencies of LV aneurysm (31%) and of pts with asynergy of more than 2 LV segments (26%), compared with 1% and 3% respectively in pts with no MI. Within the group with old MI, LVEDP was higher in pts with anterior (A) (22.0 +/- 11 mmHg, p less than .02) and anterior ł diaphragmatic (AłD) (21.5+/- 7.9 mmHg, p less than .05) MI, compared with pts with diaphragmatic (D) MI (16.6 +/- 7.1 mmHg); furthermore, LVEDP increase was significantly correlated with the severity and the extent of LV asynergy. In A and D MI, LAD and RCA stenoses or occlusions were prevalent respectively; pts with AłD MI showed larger numbers of coronary stenosis (3.05) and occlusions (1.05) per patient. The coronary artery supplying the infarcted area showed stenosis (greater than 75%) in 95.6% and was normal in 2.2% of cases. Thus, pts with CAD and old MI, and particularly of AłD and A MI, show a more compromised hemodynamic status and more severe degrees of CAD and of LV segmental wall contraction abnormality, which are responsible for their poor prognosis, compared to pts with CAD but no old MI.

Adult↗
PubMed1981

[The role of the corpus callosum and other commissures in the interhemispheric transfer of visual information].

In order to assess the contribution of the lateral suprasylvian area and subcortical pathways other than the corpus callosum in learning and interhemispheric transfer, a series of studies was undertaken in the cat. Groups of animals which received different types of cortical and subcortical lesions were tested for learning and interocular transfer of visual pattern discriminations. Results have shown that : 1. the lateral suprasylvian area is of equal importance in learning and transfer as areas 17, 18 and 19; 2. in the absence of the corpus callosum, other commissures could preserve interocular transfer of visual information. The results obtained on commissurotomized neonate kittens clearly support this assumption.

Animals↗
PubMed1980

Failure of naloxone to affect initial and acquired tolerance to ethanol in rats.

The effects of naloxone on the initial sensitivity to ethanol and the subsequent changes in tolerance induced by prior ethanol treatment were studied in rats by using the drinking test for assessing behavioral effects. Naloxone (N) was administered concurrently with ethanol (E) in either 5 successive single doses spaced at 2-day intervals (Experiment 1) or during 4 days of chronic i.v. infusion (E: 9 g/kg, N: 9 mg/kg in 6 injections per day, Experiment 2). Both treatments produced an increase in nervous tolerance toward ethanol. However naloxone was found to exert no effect on either initial or acquired tolerance toward ethanol. The results are discussed in terms of possible relations between the CNS mechanisms involved in tolerance to morphine and ethanol.

Animals↗
PubMed1980

A bioassay of ethanol-dependence in rats.

A bioassay for the quantitative assessment of ethanol dependence in rat is proposed. It is based upon the alleviation by ethanol of the withdrawal syndrome in previously intoxicated animals. The conditioning by ethanol of a taste preference, linearly related to the duration of the previous chronic intoxication, provides a reliable measure of the level of ethanol dependence. In addition, the results display the neurobehavioural mechanism by which self-maintained intoxication is established in physically dependent rats and humans.

Alcoholism↗
PubMed1980

[Anatomical study of the afferent pathways of the rostral telencephalon in the Gallus domesticus chick].

The neuroanatomical method involving retrograde axonal transport of horseradish peroxidase (HRP) was employed in the chick Gallus domesticus to investigate ascending projection systems to the rostral telencephalon. Following either extensive or restricted injections of the enzyme into different regions of the latter, differential bilateral or unilateral projections onto the Wulst (hyperstriatum accessorium, hyperstriatum intercalatus superior, hyperstriatum dorsale) were demonstrated from the dorsal thalami complex (nucleus dorsolateralis anterior thalami, pars lateralis). Other nuclei of the dorsal thalamus shown to project to the rostral telencephalon were nuclei, dorsolateralis medialis, dorsolateralis posterior, dorsomedialis anterior, parvocellularis and rotundus. At the level of the mesencephalon, rostral telencephalic projections were found to originate in the substantia grisea centralis, the strata cellulare externum and internum, the lateral reticular formation and the area ventralis. More caudally peroxidase label was localized in the nuclei locus, ceruleus, subceruleus dorsale, subceruleus ventrale and within the principal Vth nucleus. The results obtained using restricted injections of HRP made it possible to more precisely identify the telencephalic projections sites of several of the above areas and nuclei. The data is compared to previous findings regarding ascending projection system in different avian species and some methodological problems in the use of HRP technique are discussed.

Afferent Pathways↗
PubMed1980

[Diagnostic availability of R wave changes during effort test for a diagnosis of coronary artery disease (author's transl)].

New ecgraphic criteria has been proposed to improve diagnostic availability of R wave changes (delta R) and algebra summation of delta R and ST segment depression (delta RST) in comparison to the criterion of ST depression (ST). The AA. considered as a positive test for a diagnosis of coronary artery disease (CAD): delta R and delta RST values greater than or equal to 0. In 69 patients with stenosis, 75% of at least one major coronary vessel, delta RST showed correct diagnosis in 87% of cases, R in 81% and ST in 73%. RST sensitivity was better than that of ST (P = 0,02). In 44 patients with normal coronaries delta RST was able to correct diagnosis in 52% of cases, delta R in 57% and ST in 73%. ST specificity was better than that of delta RST (P = 0,04). Predictive accuracy was comparable for the three criteria. In normal healthy subjects everyone with an exercise test negative for CAD, with ST analysis, delta R and delta RST was 0 in 16% of cases. New ecgraphic criteria, also showing a better sensitivity in comparison with ST segment analysis, have a worsened specificity. The Authors do not consider these methods a significant improvement in ecgrahic evaluation of exercise test.

Adult↗
PubMed1979

[Counterimmunoelectrophoresis on cellulose acetate membrane with a commercial lyophilized antigen in diagnosis of human hydatidosis].

A very simplified method of crossed over electrophoresis (CIEP) was employed with a lyophilized commercially produced antigen (previously submitted to several freezing and thawing) and cellulose acetate membrane, for the diagnosis of human hydatidosis. Results are as follows: active hydatidosis (surgically confirmed): number of sera tested 35; positive 32 (91%). Sera of patients with parasitic and non parasitic illnesses (especially malignancies of liver and lung) did not show any precipitin lines. The pattern of immunoprecipitation is characteristically in the form of an "upper lip" or a thick and undulating "streak". The very thin arcs of precipitation which are occurring in some control sera, are to be considered negative. These results indicate that with regard to the rule of the "three S" (specificity, sensitivity and simplicity) the method appears sufficiently satisfactory.

Antibody Formation↗