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Biomedical subjects

L Bartolini

Publications and source records attributed to L Bartolini.

At least 19 recordsLinked to original sources
PubMed2004

Thrombophilic risk factors and unusual clinical features in three Italian CADASIL patients.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a genetically transmitted cerebrovascular disease. Typically, the first clinical manifestation is migraine and the full clinical spectrum of the disease with recurrent strokes of the subcortical type, cognitive, and mood disorders is seen during the fourth and fifth decades of life. Vascular risk factors are usually absent in CADASIL patients and the diagnosis of the disease is particularly suspected in young adults with cerebrovascular events of unknown cause, diffuse leukoencephalopathy on computed tomography or magnetic resonance imaging, and a history of cerebrovascular diseases or dementia in many family members. We describe three Italian CADASIL patients who presented to medical attention for cerebrovascular events occurred after the age of 55 and had, in addition to hypertension and hyperlipidemia, thrombophilic risk factors such as hyperhomocysteinemia, elevated levels of lipoprotein(a), and antiphospholipid antibodies. Symptoms possibly related to cortical involvement, such as dysphasia and visual field deficits, were reported by two of these patients. We conclude that a diagnosis of CADASIL should not be disregarded in patients with vascular risk factors and presenting with symptoms not immediately referable to subcortical damage at ages more advanced than commonly reported.

Aged↗
PubMed2002

Longitudinal evaluation of leukoaraiosis with whole brain ADC histograms.

FLAIR and diffusion-weighted MRI were obtained twice (mean interval 20 +/- 4 months) in 10 patients with leukoaraiosis. At follow-up, visual extension of leukoaraiosis was unchanged, whereas the median of whole brain apparent diffusion coefficient (WB-ADC) histogram was increased (p= 0.008) and brain volume index (BVI) was decreased (p = 0.006). WB-ADC histogram and BVI are sensitive to leukoaraiosis and might be considered for monitoring progression of the disease.

Aged↗
PubMed2001

Performance assessment of new multiplex probe assay for identification of mycobacteria.

A new DNA probe assay (INNO LiPA Mycobacteria; Innogenetics, Ghent, Belgium) for the simultaneous identification, by means of reverse hybridization and line-probe technology, of Mycobacterium tuberculosis complex, Mycobacterium kansasii, Mycobacterium xenopi, Mycobacterium gordonae, the species of the Mycobacterium avium complex (MAC), Mycobacterium scrofulaceum, and Mycobacterium chelonae was evaluated on a panel of 238 strains including, besides representatives of all the taxa identifiable by the system, a number of other mycobacteria, some of which are known to be problematic with the only other commercial DNA probe system (AccuProbe; Gen-Probe, San Diego, Calif.), and two nocardiae. The new kit, which includes a control probe reacting with the whole genus Mycobacterium, correctly identified 99.6% of the strains tested; the one discrepancy, which remained unresolved, concerned an isolate identified as MAC intermediate by INNO LiPA Mycobacteria and as Mycobacterium intracellulare by AccuProbe. In five cases, because of an imperfect checking of hybridization temperature, a very slight, nonspecific, line was visible which was no longer evident when the test was repeated. Two strains whose DNA failed amplification at the first attempt were regularly identified when the test was repeated. Interestingly, the novel kit dodged all the pitfalls presented by the strains giving anomalous reactions with AccuProbe. A unique feature of INNO LiPA Mycobacteria is its ability to recognize different subgroups within the species M. kansasii and M. chelonae, while the declared overlapping reactivity of probe 4 with some M. kansasii and Mycobacterium gastri organisms and of probe 9 with MAC, Mycobacterium haemophilum, and Mycobacterium malmoense, may furnish a useful aid for their identification. The turnaround time of the method is approximately 6 h, including a preliminary PCR amplification.

Animals↗
PubMed2001

Pulmonary function in non-insulin-dependent diabetes mellitus.

BACKGROUND: In type I diabetes mellitus, lung function has been investigated in several clinical studies, but there are few data concerning pulmonary function abnormalities in patients with non-insulin-dependent diabetes mellitus (NIDDM). OBJECTIVES: The aim of this study was to assess the presence of pulmonary function abnormalities in patients with NIDDM and to verify the possible associations between diabetic renal microangiopathy, retinopathy and diabetes control. METHOD AND PATIENTS: Thirty patients with NIDDM were collected and divided into two similar groups: subjects with retinopathy and/or diabetic glomerulopathy (group 1, n = 15) and patients without any complications (group 2, n = 15). 17 were males and 13 females, aged from 45 to 81 years. They had had diabetes for 3-23 years and were studied at the Division of Internal Medicine, with an outpatient service for diabetic patients. All patients were non-smokers. The presence of diabetic glomerulopathy was determined by measuring the 24-hour protein excretion rate using the nephelometric method. The presence of retinopathy was determined by using ophthalmoscopy. Glycosylated hemoglobin was measured as an indicator of glycemic control. We performed a global spirometry and measured pulmonary diffusion capacity by the single-breath method corrected by alveolar volume. RESULTS: We found a significant reduction in lung diffusion capacity for carbon monoxide (DL(CO)) in the group of patients with other signs of diabetic microangiopathy (p < 0.005) and a significative correlation between DL(CO )and the grade of albuminuria (r = -0.83, p < 0.001). CONCLUSIONS: Pulmonary function abnormalities, in particular a reduction in diffusion capacity, are common in patients with NIDDM and signs of diabetic microangiopathy. A possible explanation is related to an impaired pulmonary microvasculature and alveolar epithelial basal lamina.

Aged↗
PubMed2000

Comparison of Mycobacterium tuberculosis susceptibility testing performed with BACTEC 460TB (Becton Dickinson) and MB/BacT (Organon Teknika) systems.

The recently introduced automated culture systems MB/BacT (Organon Teknika, Belgium) was compared with radiometric BACTEC 460TB (Becton Dickinson, USA) to test antimicrobial susceptibility of Mycobacterium tuberculosis to first line drugs. On 113 strains 97.5% agreement was obtained, with the difference being not significant. Concordance was practically complete for the most important drugs, isoniazid and rifampin. The two methods however significantly differed for the time needed to complete the test; in fact MB/BacT required on the average five days more than BACTEC 460TB. Despite the delay in the completion of the test, the excellent reliability along with the elimination of radioactivity and full automation make MB/BacT an attractive alternative for susceptibility testing of M. tuberculosis.

Antibiotics, Antitubercular↗
PubMed1999

Effects of histamine H3 receptor agonists and antagonists on cognitive performance and scopolamine-induced amnesia.

In previous research we found that pre-training administration of histamine H3 receptor agonists such as (R)-alpha-methylhistamine and imetit impaired rat performance in object recognition and a passive avoidance response at the same doses at which they inhibited the release of cortical acetylcholine in vivo. Conversely, in the present study we report that the post-training administration of (R)-alpha-methylhistamine and imetit failed to affect rat performance in object recognition and a passive avoidance response, suggesting that H3 receptor influences the acquisition and not the recall processes. We also investigated the effects of two H3 receptor antagonists, thioperamide and clobenpropit, in the same behavioral tasks. Pre-training administration of thioperamide and clobenpropit failed to exhibit any procognitive effects in normal animals but prevented scopolamine-induced amnesia. However, also post-training administration of thioperamide prevented scopolamine-induced amnesia. Hence, the ameliorating effects of scopolamine-induced amnesia by H3 receptor antagonism are not only mediated by relieving the inhibitory action of cortical H3 receptors, but other mechanisms are also involved. Nevertheless, H3 receptor antagonists may have implications for the treatment of degenerative disorders associated with impaired cholinergic function.

Amnesia↗
PubMed1998

Effect of subchronic treatment with metrifonate and tacrine on brain cholinergic function in aged F344 rats.

The effects of 21-day treatment with the acetylcholinesterase inhibitors metrifonate (80 mg kg(-1) per os (p.o.)) and tacrine (3 mg kg(-1) p.o.), twice daily, on cortical and hippocampal cholinergic systems were investigated in aged rats (24-26 months). Extracellular acetylcholine levels were measured by transversal microdialysis in vivo; choline acetyltransferase and acetylcholinesterase activities were measured ex vivo by means of radiometric methods. Basal cortical and hippocampal extracellular acetylcholine levels, measured 18 h after the last metrifonate treatment, were about 15 and two folds higher, respectively, than in control and tacrine-treated rats. A challenge with metrifonate further increased cortical and hippocampal acetylcholine levels by about three and four times, respectively. Basal extracellular acetylcholine levels, measured 18 h after the last treatment with tacrine were not statistically different from those of the control rats. A challenge with tacrine increased cortical and hippocampal extracellular acetylcholine levels by about four and two times. A 75% inhibition of cholinesterase activity was found 18 h after the last metrifonate administration, while only a 15% inhibition was detectable 18 h after the last tacrine administration. The challenge with metrifonate or tacrine resulted in 90 and 80% cholinesterase inhibition, respectively. These results demonstrate that in aging rats a subchronic treatment with metrifonate results in a long-lasting, cholinesterase inhibition, and a persistent increase in acetylcholine extracellular levels which compensate for the age-associated cholinergic hypofunction. Metrifonate is therefore a potentially useful agent for the cholinergic deficit accompanying Alzheimer's disease.

Acetylcholine↗
PubMed1998

Acetylcholine release from the frontal cortex during exploratory activity.

The activation of the cortical cholinergic system was investigated in 3- and 25-month-old male Wistar rats, by measuring by transversal microdialysis the changes in cortical extracellular acetylcholine (ACh) levels during the performance of simple spontaneous tasks involving exploratory activity and working memory. Two days after implantation of the microdialysis probe in the frontal cortex, object recognition was investigated by either moving the rats from the home cage to the arena containing the objects or keeping the rats in the arena and introducing the objects. Spontaneous alternation was investigated in a Y runway. Young rats discriminated between familiar and novel objects and alternated in the Y runway, while aged rats were unable to discriminate. Whenever rats were moved from the home cage to the arena, ACh release increased (+70-80%) during the exploratory activity. Handling per se had no effect on extracellular ACh levels. When young rats were left in the arena, introduction of the objects caused some exploratory activity and object recognition but no increase in ACh release. ACh release increased by about 300% during spontaneous alternation. In aging rats basal extracellular ACh levels and their increase after placement in the arena were less than half that in young rats. Our work demonstrates that a novel environment activates the cortical cholinergic system, which presumably is associated with arousal mechanisms and selective attentional functions. It also demonstrates that in aging rats the cortical cholinergic hypofunction is associated with a loss of non-spatial working memory.

Acetylcholine↗
PubMed1998

Reticulocytes and reticulated platelets: simultaneous measurement in whole blood by flow cytometry.

Reticulated platelets are a fraction of newly released circulating elements characterized by a residual amount of RNA. It has been suggested that the reticulated platelet count, providing an estimate of thrombopoiesis in the same way as erythrocyte reticulocyte count is a measure of erythropoiesis, may be useful in the study of thrombocytopenic disorders. Reticulated red cells and platelets can be analyzed by flow cytometry using specific stains for nucleic acids such as Thiazole Orange and Auramine-O. The aim of our work was to perform the simultaneous evaluation of reticulated elements in whole blood using a standard flow cytometer and to correlate the results obtained with a dedicated cytometer. A group of 14 patients with abnormal absolute reticulocyte counts (range 1.1-11%) and a group of 41 patients showing a platelet discrimination error when analyzed with a dedicated flow cytometer (Sysmex R1000) were enrolled. Linear amplification of both scatter and fluorescence was used to perform reticulocyte count. A gate was set on platelet dimensions, and logarithmic amplification of scatter and fluorescence was used to count reticulated platelets. A good correlation was obtained both for results of reticulocyte count (r2 = 0.9825) and for reticulated platelets (r2 = 0.8717) between our method and those using dedicated instruments. These data show that reticulated platelet count may be easily introduced in clinical laboratories that routinely perform reticulocyte count by flow cytometry.

Benzophenoneidum↗
PubMed1997

Effect of metrifonate on extracellular brain acetylcholine and object recognition in aged rats.

The effects of metrifonate were investigated in 4-6- and 22-24-month-old rats. Extracellular acetylcholine levels were measured by transversal microdialysis in vivo. Baseline extracellular acetylcholine levels in the cerebral cortex and hippocampus were 42% and 60% lower, respectively, in old than in young rats. Old rats did not discriminate between familiar and novel objects. In old rats, metrifonate (80 mg/kg p.o.) brought about 85% inhibition of cholinesterase activity in the cortex and hippocampus, a 4-fold increase in extracellular acetylcholine levels in the cortex only, and restored object recognition. In young rats, metrifonate caused 75% cholinesterase inhibition in the cerebral cortex and hippocampus, a 2-fold increase in cortical and hippocampal extracellular acetylcholine levels, and no effect on object recognition. The slight cholinesterase inhibition following metrifonate (30 mg/kg) in aged rats had no effect on cortical acetylcholine levels and object recognition. In conclusion, metrifonate may improve the age-associated cholinergic hypofunction and cognitive impairment.

Acetylcholine↗
PubMed1997

Tacrine administration enhances extracellular acetylcholine in vivo and restores the cognitive impairment in aged rats.

The effect of oral tacrine administration on cortical and hippocampal extracellular acetylcholine (ACh) levels has been investigated by a microdialysis technique, coupled to a HPLC method, in 6- and 22-24-month-old rats. In order to assess whether the increase in extracellular ACh levels was associated with an improvement in the age-related cognitive impairment, the object recognition and step-trough passive avoidance tests were carried out in the treated rats. The extracellular ACh levels measured in the cortex and hippocampus of aged rats without cholinesterase inhibitor in the perfusion Ringer solution were 39 and 54% lower, respectively, than in the young rats. At the dose of 3 mg kg-1, tacrine brought about a three- to four-fold increase in extracellular ACh levels, both in young and aged rats, which peaked 60-80 min after administration and disappeared within the next 60 min. At the same dose, tacrine caused a twofold increase in extracellular ACh levels in the hippocampus of young rats and a sixfold increase in aged rats. The absolute ACh levels at the peak in aged rats were not significantly different from those of young rats. In the object recognition test, aging rats were unable to discriminate between the familiar and novel object. Discrimination was restored by the administration of tacrine at the dose of 1 and 3 mg kg-1, but not 0. 3 mg kg-1 given 30 min before the first trial. Tacrine (3 mg kg-1 p. o.) administered to aging rats before the training trial significantly improved the acquisition of the passive avoidance conditioned response. Our findings demonstrate that tacrine increased both cortical and hippocampal extracellular ACh levels and improved behavioural functions in aged rats.

Acetylcholine↗