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Biomedical subjects

A Bartolini

Publications and source records attributed to A Bartolini.

143 records · Page 8Linked to original sources
PubMedDate not supplied

Assessment of regional cerebral blood flow images with non-diffusible contrast media and angio-CT. Comparison with Xe-CT.

We derived rCBF (ND-rCBF) images using non-diffusible contrast agent time-density curves obtained by monitoring the first pass with an angio-CT sequence. An appropriate elaboration of the sequence of the images led to the generation of vascular volume (Vv) and regional Arm-Brain circulation time images (rABCT). ND-rCBF was obtained by dividing the Vv image by the rABCT image after having rendered them suitable for such an operation. Regional cerebral vascular volume (rCBF) was assessed by standardizing Vv values with blood contrast concentration and intracranial circulation time (rICT) by subtracting from the rABCT image the inflow mean time, assessed as the lowest rABCT value of the slice. The ND-rCBF images were qualitatively fairly well comparable with synchronous rCBF (D-rCBF) images obtained with the Xe-CT technique. However quantitation of the values by ROI use gave different results, the ND-rCBF image showing considerably higher values. Using indicator images to analyse the rCBF values at different levels of rCBV and rICT, it was shown that there was a significant relation between the two ND-rCBF and D-rCBF values in the 70-80% pixels with higher rABCT and lower rCBF values.

Angiography↗
PubMedDate not supplied

Assessment of the CO2 response by means of non diffusible contrast media and angio-CT in patients with cluster headache.

We analyzed the possibility of assessing functional vasomotor changes by means of Arm-Brain Circulation Time (rABCT) and Vascular volume images (Vv) obtained with Angio-CT, in basal condition and following CO2 inhalation, in a sample of 48 patients with cluster headache. CO2 inhalation resulted in the appearance of local changes, which were detected in 28 regions. Analysis by indicator images of Vv-dependent rABCT distribution showed two main patterns: abnormal rABCT mostly evident at the smallest Vv pixels and abnormal rABCT dependent on abnormal Vv distribution. The former pattern was linked to abnormality at the circle of Willis; the latter to abnormal local vasomotor responses. Patients with cluster headache showed both patterns, which prompted us to conclude for the presence of low-degree stenosis in carotid arteries and vasomotor instability in peripheral brain vessels.

Adult↗
PubMedDate not supplied

M1 receptor activation is a requirement for arecoline analgesia.

Arecoline. a drug obtained from the Areca Catechu L., induced a dose-dependent antinociception (0.3-1 mg kg(-1) i.p.) which was prevented by the muscarinic antagonists pirenzepine (0.1 microg per mouse i.c.v.) and S-(-)-ET-126 (0.01 microg per mouse i.c.v.). A dose-dependent inhibition of the antinociception induced by arecoline was observed after inactivation of the M1 gene by an antisense oligodeoxyribonucleotide (aODN). This effect was detected 24 h after the last i.c.v. injection of aODN. These results indicate that arecoline antinociception is mediated by the activation of central M1 muscarinic receptors.

Analgesics, Non-Narcotic↗
PubMedDate not supplied

Local anaesthetic activity of beta-caryophyllene.

In this work we studied the local anaesthetic activity of beta-caryophyllene, one of the main components of clove oil obtained from the dried flower-buds of Syzygium aromaticum (Myrtaceae family). We compared its activity to a chemically related compound, caryophyllene oxide. Anaesthetic activity was evaluated in vivo in the rabbit conjunctival reflex test and in vitro in a rat phrenic nerve-hemidiaphragm preparation. Beta-caryophyllene (10(-4) - 1 microg/ml), but not caryophyllene oxide, was able to reduce drastically, in a dose-dependent manner, the electrically evoked contractions of the rat phrenic hemidiaphragm. In the rabbit, conjunctival reflex test treatment with a solution of beta-caryophyllene (10-1000 microg/ml) allowed a dose-dependent increase in the number of stimuli necessary to provoke the reflex. As in the in vitro results, caryophyllene oxide was ineffective also in the in vivo test. In conclusion, these data evidence the local anaesthetic activity of beta-caryophyllene, which appears to be strictly dependent on its chemical structure.

Anesthetics, Local↗
PubMedDate not supplied

Intravenous 99mTc HM-PAO radionuclide angiography as an adjunct to SPECT assessment of cerebral disease.

An application of intravenous radionuclide angiography as an adjunct to SPECT with 99mTc HM-PAO is presented. From the angiographic sequence a two-dimensional parametric image is generated computing, pixel by pixel, the center of gravity (COG) of the local time curves. This index is independent of blood flow and reflects the relation between transmitted and extravasated activity. COG value, compared in two symmetrical regions analyzed for differences in flow by SPECT, may help to state whether a detected SPECT changed uptake is linearly related or not to the corresponding change of blood flow. All 23 ischemic patients taken into consideration had a similar backflux in symmetrical regions with conspicuous changed uptake. In 3 meningiomas and 2 arteriovenous angiomas it was possible to detect the occurrence of a changed backflux in the lesion suggesting a nonlinearity between blood flow and 99mTc HM-PAO uptake.

Brain Ischemia↗
PubMedDate not supplied

Central cholinergic challenging of migraine by testing second-generation anticholinesterase drugs.

The antinociceptive activity of donepezil, a novel cholinesterase inhibitor, was investigated in the mouse hot plate test. Donepezil (5 to 10 mg kg(-1) i.p.) induced a dose-dependent antinociception that reached its maximum effect 15 minutes after injection. Donepezil antinociception was prevented by the antimuscarinic drug scopolamine. At analgesic doses, donepezil did not alter gross animal behavior. These results indicate that donepezil is endowed by muscarinic antinociceptive properties, suggesting this compound as a potential therapeutic approach for the treatment of painful pathologies. Therefore, we investigated donepezil's effect in migraine. Donepezil (5 mg per os, evening assumption) was effective as a prophylatic agent in patients suffering from migraine with or without aura by reducing the number of hours with pain, the number of attacks, and the severity of the pain attack. The efficacy of donepezil was compared with that of the beta-blocker propranolol (40 mg bid per os), showing higher activity. Response rates of a large-sized open study devoid of entry criteria regarding migraine subtypes suggest the drug as an excellent prophylactic compound for migraine in general practice. Clinical results also indicate that the activation of the cholinergic system can represent a novel prophylactic approach to migraine.

Adrenergic beta-Antagonists↗
PubMedDate not supplied

Regional arm-brain mean transit time in the diagnostic evaluation of patients with cerebral vascular disease.

By analyzing time-activity curves over selected brain regions, following intravenous administration of non-diffusible radionuclide, it is possible to assess regional arm-brain mean transit time (rABmtT). By evaluating this parameter in normal subjects a relatively small range of differences between asymmetrical regions can be found (0.30 +/- 0.14 sec, mean +/- SD). An increase of this difference above statistical limits was found in 82% of patients with acute complete stroke, in 56% of patients with chronic complete stroke in 21% of patients with transient ischemic attacks.

Arm↗
PubMedDate not supplied

[Computerized radionuclide angiography of brain tumors. Analysis of activity-time curves].

43 patients with a cerebral supratentorial tumor and an increased uptake at the static scan underwent intravenous radionuclide angiography with time-activity curve analysis. The increased uptake was evident during radionuclide angiography in about 50% of the cases, 16% during the upslope and 40% during the downslope of the curve. From these data it was concluded that increased uptake in tumours is determined rather than by an increased blood flow by the barrier disruption which may be operative in determining the increased uptake during the first pass in about 40% of the cases. In this case thy typical modification of the curve is characterized by a decreased falling rate of the downslope.

Blood-Brain Barrier↗
PubMedDate not supplied

Regional cerebral mode transit time and the derivative of the regional cerebral function recorded for intravenous administration of a non-diffusible tracer.

The meaning of the time from origin to first peak and from peak to peak of the derivative of the regional cerebral functions recorded after intravenous administration of a non-diffusible tracer is analyzed. Data obtained by cerebral and cardiac monitoring and evaluation of both times in patients with carotid thrombosis, indicates that the time from origin to first peak may be a better estimate of regional cerebral mode transit time than the time from peak to peak.

Brain↗