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Biomedical subjects

A Leoni

Publications and source records attributed to A Leoni.

At least 55 records · Page 3Linked to original sources

[Modifications of the Portoscuso ecosystem. Distribution, accumulation,and dynamics of pollutants. I. Observations on animal tissues].

In order to assess the extent of environmental pollution by Pb, Cd and Zn in the industrial area of Portoscuso (Southwestern Sardinia-Italy), anatomohistopathological, histochemical and chemical tests were carried out on the heart, liver, kidneys and bones of sheep slaughtered in the local abattoir. On microscopic examination, degenerative lesions were severe in liver and kidneys and slight in the heart; histochemical stainings clearly showed a notable presence of Zn, while spectrophotometric examination confirmed, besides Zn pollution, very high tissue concentrations of Pb and Cd. The Authors conclude that other trial observations over larger areas are necessary.

Animals↗

[Experimental listeriosis in chickens: microbiological and anatomo-histopathological studies and health and hygiene considerations].

The authors report the results of an experimental infection of 20 chickens with L.m. in order to verify if they became affected by Listeriosis and to individuate the degree of contamination of the meat and parenchymas and eggs. Despite the high infecting dose (160 x 10(7) micro-organism in group 1, 51 x 10(8) + cortisone in group 2, 130 x 10(8) in group 3), no signs of the disease were found in any of the animals; besides, L.m. was isolated in the faeces of only 3 subjects for 1 day post-infection and in the organs of 4 subjects for a maximum of 15 days post-infection. From a histopathological point of view only simple lymphocytic-macrophagic and eosinophilic proliferations localized in the liver and, to a lesser extent, in other parenchymas were observed. The authors advance the hypothesis that the frequent isolations of L.m. in chicken meat and eggs can be attributed to exogenous contamination in stages of slaughtering and marketing of the product.

Abattoirs↗

Synthesis, antibacterial activity and structure-activity relationships of N-substituted 4-diazo-pyrazole-5-carboxamides. 2.

A series of 4-diazopyrazole-5-carboxamides 1 d-n has been synthesized and their antibacterial activity against a number of Gram-negative and Gram-positive strains has been tested. Some of the compounds resulted quite active and the whole set allowed to further study the SAR of the class. Substituents in position 5 affect Gram-negative and Gram-positive activities via bulk and electronic properties respectively; position 3 mostly affects the Gram-negative activity, while the presence of the charged diazo group in position 4 is crucial for both antibacterial activities.

Amides↗

Evaluation of ischaemic necrosis of carpal bones by magnetic resonance imaging.

Nine patients with chronic pain in the wrist were examined by M.R.I. to evaluate its accuracy in the detection of ischaemic necrosis of carpal bones. In seven patients, M.R.I. confirmed scintigraphic and radiographic signs of ischaemic necrosis. In two patients with radionuclide accumulations, M.R.I. did not confirm the diagnosis: in one, M.R.I. was totally normal and in the other it showed signs of a healing scaphoid fracture. From this limited experience, M.R.I. seems to be a sensitive imaging modality which is more specific than scintigraphy.

Carpal Bones↗

[Doppler flowmetry in the study of portal hypertension in patients with liver cirrhosis. Qualitative and quantitative analyses].

The recent development of the duplex-Doppler technique, which combined real-time US with pulsed Doppler flowmetry, has allowed the flowmetric hemodynamic study of large abdominal vessels. As yet, however, both accuracy and possible applications of this method in the study of portal hypertension have not been fully investigated. This study was aimed at assessing whether or not the combined use of Doppler flowmetry and bidimensional US is able to detect portal hypertension in patients with liver cirrhosis (LC), and could therefore represent a valid alternative to endoscopic, angiographic, and direct pressure measurement techniques. Twenty-six patients with LC and 25 control patients were studied with a strictly standardized method; portal hypertension was detected in the patients with LC by EGDS and laparoscopy. The results demonstrated pulsed duplex-Doppler US to be able to detect portal hypertension in 92.4% of LC patients, with 2 false negatives only (7.6%). The difference in the flowmetric data of normal and LC patients was highly significant (p less than 0.001 Student's t test). In conclusion, duplex-Doppler US can be considered as a valid technique to detect portal hypertension in LC patients, and can thus be used as an alternative to more invasive techniques of general use in clinics.

Adult↗

[Rotator cuff lesions: evaluation with RM and US].

Physical and instrumental examination of the patients with an "aching shoulder" is often difficult and a positive out-come of surgical treatment may be impaired by the late diagnosis of long-standing rotator cuff lesions causing tendon adhesions and muscle atrophy. The authors report the results obtained in 25 selected patients with an aching shoulder examined with arthrography, real-time ultrasound (US) with a 5 MHz linear probe, and high-field (1.5 T) Magnetic Resonance (MR) imaging. Arthrography was able to demonstrate a cuff tear in 14/25 cases; US detected signs of tear in 14/25 (1 false negative); MR imaging showed a cuff lesion in 16/25 patients, and in one case allowed a partial cuff tear to be demonstrated, which had not been visualized with arthrography. MR imaging could also demonstrate other signs of periarticular pathologies (tendinitis, longhead of biceps inflammation, and bursitis) that may represent the early stages of the inflammatory-degenerative process underlying most of cuff lesions. The high diagnostic accuracy of US (95%) is stressed in the detection of cuff tears, in patients with an aching shoulder; as for questionable cases at US, MR imaging is indicated as a valid alternative to arthrography, which is more invasive and less accepted by the patients.

Arthrography↗

[1.5 T MR in the diagnosis of parotid masses: comparison with ultrasonography].

Twenty-two patients who presented with laterocervical retromandibular enlargement were examined with both US and MR imaging to assess the intrinsic/extrinsic relationship of the mass to the parotid gland, the involvement of the facial nerve and adjacent structures, as well as the nature of the mass. Both US and MR imaging proved to be poorly specific in the characterization of the inflammatory lesions. Within the mass, both methods revealed high sensitivity (100%) in identifying the lesions, even very small ones. MR imaging allowed the lesion to be accurately located, the facial nerve to be identified, and its possible infiltration to be evaluated, with higher reliability than US, thanks to its higher contrast resolution and to its multiplanarity. Neither US nor MR imaging allowed the benign/malignant nature of the lesion to be assessed. On the basis of their experience, the authors suggest the use of T2-weighted MR sequences, with long TR and TE, to differentiate pleomorphic adenomas from other histotypes, after US assessment of the solid nature of parotid masses.

Adenocarcinoma↗

[1.5-T MR of the knee: the correlations with arthroscopy].

The authors report their experience of knee articular pathologies studied with MR imaging. Forty patients (36 with and 4 without articular trauma) were examined with both MR imaging and arthroscopy. Arthroscopic findings were correlated with MR results in order to evaluate the accuracy of the latter in detecting meniscal tears. MR images were obtained with a 1.5 T unit and a transmit-receiver surface coil. Spin-echo sequences and, occasionally, fast-scan sequences were used both in the coronal and in the sagittal planes. High resolution MR imaging clearly depicted knee anatomy. As far as meniscal lesions were concerned, the authors employed a grading system to classify intrameniscal signals, as proposed by Lotysch. The preliminary results are encouraging and suggest the use of MR imaging as the first imaging modality for use in knee pathology before arthroscopy is performed.

Adolescent↗

[Neurotoxic syndrome of sheep due to the ingestion of plants of the Mediterranean scrub: clinical, histopathological, histochemical and ultrastructural observations].

A severe neurological disorder was observed during a very dry season, in sheep pasturing on land with mediterranean vegetation. During the crisis, lasting 5-20", ataxia and convulsions were the main clinical signs. Brain congestion, spongy appearance of the liver, interstitial nephritis and hyperpigmentation of visceral lymph nodes were the most important macroscopic lesions. Histopathological, histochemical and ultrastructural findings confirmed liver and kidney lesions and showed considerable neurovisceral storage of lipofuscin. Although further toxicological and experimental studies are needed to elucidate the origin of the disease, the Authors attribute the outbreak of the neurological syndrome to the ingestion of a neurotoxin containing plant.

Animals↗

Computed tomography and magnetic resonance imaging of cerebral coenurosis.

A case of Coenurus cerebralis involving both cerebral hemispheres and the interpeduncular cistern is presented to illustrate the computed tomography (CT) and magnetic resonance imaging (MRI) features. In CT scans viable cysts appear as lucent lesions surrounded by a contrast-enhanced peripheral rim. By using multiple echo sequences the cyst content is characterized in magnetic resonance images by a cerebrospinal fluid-like intensity pattern.

Brain Diseases↗

Prolidase deficiency in two siblings with chronic leg ulcerations. Clinical, biochemical, and morphologic aspects.

Prolidase deficiency occurred in two sisters suffering from recurrent leg ulcers that appeared in early childhood. The patients presented the typical clinical symptoms of the disease, including characteristic facies, dermatologic manifestations of the lower extremities, splenomegaly, and hematologic anomalies. Large amounts of iminodipeptides were excreted into the urine, and prolidase activity in their erythrocytes was virtually absent. Changes associated with a connective-tissue disorder were demonstrated by light and electron microscopic studies of the patients' apparently normal skin. Collagen fibers were smaller than in controls and were irregularly packed; the fibrils had normal aspect but were significantly smaller than in one age-matched control. Elastin fibers appeared altered both in size and structure.

Adult↗